{{Short description|Extinct genus of endemic Paleogene European artiodactyls}} {{good article}} {{Automatic taxobox | fossil_range = Late [[Eocene]] – early [[Oligocene]] {{fossil range|37|33.4}} {{Period fossil range|Paleogene|37|33.4}} | image = Anoplotherium commune.jpg | image_upright = 1.3 | image_caption = ''Anoplotherium commune'' incomplete skeleton from the commune of [[Pantin]], [[National Museum of Natural History, France]] | image2 = Anoplotherium commune skull 567897.jpg | image2_caption = Skull of ''Anoplotherium commune'' at the National Museum of Natural History, France | taxon = Anoplotherium | authority = [[Georges Cuvier|Cuvier]], 1804 | type_species = {{extinct}}'''''Anoplotherium commune''''' | type_species_authority = Cuvier, 1804 | subdivision_ranks = Other species | subdivision = {{species list |{{extinct}}'''''A. laurillardi'''''|[[Auguste Pomel|Pomel]], 1851 |{{extinct}}'''''A. latipes'''''|[[Paul Gervais|Gervais]], 1852 |{{extinct}}'''''A. pompeckji'''''|[[Wilhelm Otto Dietrich|Dietrich]], 1922 }} | synonyms = {{collapsible list|bullets = true|title=Genus synonymy | ''Eurytherium'' {{small|Gervais, 1852}} }} {{collapsible list|bullets = true |title=Synonyms of ''A. commune'' | ''Anoplotherium duvmoyi'' {{small|Pomel, 1851}} }} {{collapsible list|bullets = true |title=Synonyms of ''A. latipes'' | ''Anoplotherium platypus'' {{small|Pomel, 1851}} | ''Anoplotherium tridactylum'' {{small|[[Vladimir Kovalevsky|Kovalevsky]], 1873}} }} {{collapsible list|bullets = true |title=Synonyms of ''A. laurillardi'' | ''Anoplotherium cuvieri'' {{small|Pomel, 1851}} }} }} '''''Anoplotherium''''' is the [[type genus]] of the extinct [[Paleogene|Palaeogene]] [[artiodactyl]] family [[Anoplotheriidae]], which was endemic to [[Western Europe]]. It lived from the Late [[Eocene]] to the earliest [[Oligocene]]. It was the fifth fossil mammal genus to be described with official taxonomic authority, with a history extending back to 1804 when its fossils from [[Montmartre]] in [[Paris]], France were first described by the French naturalist [[Georges Cuvier]]. Discoveries of incomplete skeletons of ''A. commune'' in 1807 led Cuvier to thoroughly describe unusual features for which there are no modern analogues. His drawn skeletal and muscle reconstructions of ''A. commune'' in 1812 were amongst the first instances of anatomical reconstructions based on fossil evidence. Cuvier's contributions to palaeontology based on his works on the genus were revolutionary for the field, not only proving the developing ideas of [[extinction]] and ecological succession but also paving the way for subfields such as [[paleoneurology|palaeoneurology]]. Today, there are four known species. ''Anoplotherium'' was amongst the largest non-[[Whippomorpha|whippomorph]] artiodactyls of the Palaeogene period, weighing on average {{cvt|115|kg}} to {{cvt|271|kg}} and measuring at least {{cvt|2.5|m}} in head and body length and {{cvt|1.25|m}} in shoulder height. It was an evolutionarily advanced and unusual artiodactyl, sporting three-toed feet in certain species like ''A. latipes'', a long and robust tail, and a highly-developed brain with strong support for both sense of smell and [[sensory perception]]. Its overall robust build and elongate tail has been suggested to have allowed it to stand bipedally like a [[gerenuk]] to browse on plants at greater heights, reaching approximately {{cvt|3|m}} tall, effectively competing with the few other medium to large herbivores it lived with. The full extent of its bipedalism needs to be confirmed by more research, however. The larger, two-toed ''A. commune'' and slightly smaller, three-toed ''A. latipes'' may be sexual dimorphs in that the former is female and the latter male, but this idea remains speculative. Its closest relative was ''[[Diplobune]]'', which similarly is hypothesized to have had specialized behaviours. The artiodactyl lived in western Europe back when it was an [[archipelago]] that was isolated from the rest of Eurasia, meaning that it lived in an environment with various other faunas that also evolved with strong levels of endemism. Its exact origins are unknown, but it arose long after a shift towards drier but still subhumid conditions that led to abrasive plants and the extinctions of the large-sized [[Lophiodontidae]], achieving [[gigantism]] and establishing itself as a dominant herbivore throughout the entirety of the western European region given its abundant fossil evidence. ''Anoplotherium'' was recorded up to the earliest Oligocene, which largely coincided with shifts towards further glaciation and seasonality as part of the [[Grande Coupure]] extinction and faunal turnover event in the earliest Oligocene of western Europe. Tropical and subtropical forests were rapidly replaced by more temperate environments, and most ocean barriers previously separating western Europe from eastern Eurasia closed, allowing for large faunal dispersals from Asia. Although the specific causes are uncertain, Anoplotherium was likely unable to adapt to these major changes for long and succumbed to extinction. == Taxonomy == === Research history === {{Main|Research history of Anoplotherium|l1=Research history of ''Anoplotherium''}} ==== Identifications ==== {{multiple image | align = left | image1=Anoplotherium 1804 Cuvier Lower Jaw.png | image2=Anoplotherium 1804 Cuvier Limbs 1.png | footer = Sketches of dental, cranial, and limb remains of ''Anoplotherium commune'' by [[Georges Cuvier]], 1804 }} While Georges Cuvier knew about fossil bones from the gypsum quarries of the outskirts of [[Paris]] (known as the [[Paris Basin]]) as early as at least 1800, it was not until 1804 that he would describe them. After describing ''[[Palaeotherium]]'', he wrote about the next set of fossils that he was able to discern as being different from ''Palaeotherium'' based on dentition form, including the apparent lack of [[canine (tooth)|canines]] that left a large gap between the [[incisor]]s and [[premolar]]s. He observed that the hemimandible (half a [[mandible]]) had three lower incisors instead of four incisors or none which he said characterized other "[[Pachydermata|pachyderms]]". Cuvier, basing the name on its apparent lack of suitable arms and canines for offensive attacks, erected the name ''Anoplotherium''.{{cite journal|last=Cuvier|first=Georges|year=1804|title=Suite des Recherches: Sur les espèces d'animaux dont proviennent les os fossiles répandus dans la pierre à plâtre des environs de Paris.|journal=Annales du Muséum National d'Histoire Naturelle, Paris|language=french|volume=3|pages=364–387|url=https://www.biodiversitylibrary.org/item/51193#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-07-27|archive-url=https://web.archive.org/web/20230727022652/https://www.biodiversitylibrary.org/item/51193#page/1/mode/1up|url-status=live}}{{cite journal|last=Rudwick|first=Martin J. S.|year=2022|title=Georges Cuvier's appeal for international collaboration, 1800|journal=History of Geology|volume=46|number=1|pages=117–125 |doi=10.18814/epiiugs/2022/022002|s2cid=246893918|doi-access=free}} The [[genus name]] ''Anoplotherium'' means "unarmed beast" and is a compound of the [[Greek language|Greek]] words {{lang|grc|αν-}} ({{translit|grc|an}}, 'not'), {{lang|grc|ὅπλον}} ({{translit|grc|hóplon}}, 'armor, large shield'), and {{lang|grc|θήρ}} ({{translit|grc|thēr}}, 'beast, wild animal').{{cite book |last1=Roberts |first1=George |title=An etymological and explanatory dictionary of the terms and language of geology |year=1839 |publisher=Longman, Orme, Brown, Green, & Longmans |location=London |page=8 |url=https://archive.org/details/anetymologicala00robegoog |access-date=29 December 2021 |language=English}} Cuvier named three species of ''Anoplotherium'' in the same year, the first of which was the "sheep-sized" ''A. commune'' and the other three of which were "smaller species" that he named ''A. medium'', ''A. minus'', and ''A. minimum''. The etymology of the species name ''A. commune'' refers to how "common" fossils of the species were while the etymologies of the other two species were based on sizes compared to ''A. commune''.{{efn|Latin {{lang|la|commune}} is the neuter form of ''communis'', which translates in English to 'common'.}} He also attributed a [[cloven hoof]] (or didactyl hoof) to ''A. commune'' since the specimen appeared to be large-sized. He thought that ''Anoplotherium'' had didactyl hooves instead of tridactyl hooves, which would have separated it from ''Palaeotherium''. Based on the hooves and dentition, he concluded that ''Anoplotherium'' was similar to [[ruminant]]s or [[camelid]]s.{{cite journal|last=Cuvier|first=Georges|year=1804|title=Suite des Recherches: Suite de recherches sur les os fossiles de la pierre à plâtre des environs de Paris. Troisième mémoire. Restitution des pieds. Première section. Restitution des différens pieds de derrière.|trans-title=Continuation of Research: Further research on the fossil bones from the gypsum quarries in the vicinity of Paris. Third memoir. Reconstruction of the feet. First section. Reconstruction of the various hind feet.|journal=Annales du Muséum National d'Histoire Naturelle, Paris|language=french|volume=3|pages=442–472|url=https://www.biodiversitylibrary.org/item/51193#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-07-27|archive-url=https://web.archive.org/web/20230727022652/https://www.biodiversitylibrary.org/item/51193#page/1/mode/1up|url-status=live}}{{cite journal|last=Cuvier|first=Georges|year=1805|title=Troisième mémoire. Deuxième section. Restitution des différens pieds de devant.|trans-title=Third Memoir. Second Section. Reconstruction of the various forefeet.|journal=Annales du Muséum National d'Histoire Naturelle, Paris|language=french|volume=6|pages=253–283|url=https://www.biodiversitylibrary.org/item/92466#page/1/mode/1up|access-date=2023-08-30|archive-date=2012-11-10|archive-url=https://web.archive.org/web/20121110230536/http://www.biodiversitylibrary.org/item/92466#page/1/mode/1up|url-status=live}} However, in 1807, Cuvier found out that ''Anoplotherium commune'' had three toes on its hind limbs, although the third index toes were of smaller sizes compared to the other two.{{cite journal|last=Cuvier|first=Georges|year=1807|title=Suite des recherches sur les os fossiles des environs de Paris. Troisième mémoire, troisième section, les phalanges. Quatrième mémoire sur les os des extrémités, première section, les os longs des extrémités postérieures.|trans-title=Continuation of research on fossil bones from the vicinity of Paris. Third memoir, third section: the phalanges. Fourth memoir on the bones of the limbs, first section: the long bones of the hind limbs.|journal=Annales du Muséum d'Histoire Naturelle|volume=9|pages=10–44|url=https://www.biodiversitylibrary.org/item/23267#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-09-02|archive-url=https://web.archive.org/web/20230902170002/https://www.biodiversitylibrary.org/item/23267#page/1/mode/1up|url-status=live}} ==== Skeletons ==== {{multiple image | align = right | image1 = Anoplotherium Commune skeleton 1807 1.png | image2 = Anoplotherium Commune skeleton 1807 2.png | total_width = 450 | footer = Sketches of two incomplete, embedded skeletons of ''Anoplotherium commune'', found in the communes of [[Pantin]] (left skeleton) and [[Antony, Hauts-de-Seine|Antony]] (right skeleton) }} In 1807, Cuvier wrote about two incomplete skeletons that were recently uncovered, although the first was partially damaged because it was not collected carefully (which he expressed as having frustrated his understanding of the skeletal anatomy of ''Anoplotherium'' initially). The first skeleton, found in the quarries of [[Montmartre]] in the commune of [[Pantin]], helped to confirm Cuvier's earlier diagnoses of ''Anoplotherium'' as correct. The embedded skeleton was the size of a small horse and helped to confirm the large didactyl feet and the 44 total teeth that it had (11 in each side of its jaw). It also had 11 complete ribs and a fragment of a 12th, matching with the number of ribs of camelids. The most surprising element to Cuvier, however, was the enormous tail with 22 vertebrae in the skeleton, a feature that he said he would not have known about previously, as there are no modern analogues of the elongated and thick tail in any large quadrupedal mammal.{{cite journal|last=Cuvier|first=Georges|year=1807|title=Suite des recherches sur les os fossiles des environs de Paris. Ve mémoire, IIe section, description de deux squelettes presque entiers d'Anoplotherium commune.|trans-title=Continuation of research on fossil bones from the vicinity of Paris. Memoir Ve, Section IIe: description of two nearly complete skeletons of Anoplotherium commune.|language=french|journal=Annales du Muséum d'Histoire Naturelle|volume=9|pages=272–282|url=https://www.biodiversitylibrary.org/item/23267#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-09-02|archive-url=https://web.archive.org/web/20230902170002/https://www.biodiversitylibrary.org/item/23267#page/1/mode/1up|url-status=live}} The second incomplete skeleton came from [[Antony, Hauts-de-Seine|Antony]], this time more carefully removed with supervision from experts than the first skeleton. In it, he was able to confirm six [[lumbar vertebrae]] and three [[sacral vertebrae]], all of which were extremely strong and probably supported the long tail. Most notable to Cuvier was the confirmation that ''Anoplotherium'' had two large fingers and one small finger on its front legs, which was unusual for mammals related to it. ==== Significance in palaeontological history ==== [[File:Anoplotherium commune 667.JPG|thumb|left|''Anoplotherium commune'' skull, [[National Museum of Natural History, France]]]] Although ''Palaeotherium'' and ''Anoplotherium'' are not well-recognized compared to fossil animals of other periods (i.e. [[Mesozoic]] dinosaurs and [[Neogene]]-[[Quaternary]] mammals), their fossil discoveries in Montmartre and formal descriptions by Cuvier are recognized as critical moments that pioneered palaeontology to the modern era. Unlike [[Pleistocene]] fossil genera in the Americas in early palaeontological history such as ''[[Megatherium]]'' and ''[[Mammut]]'', ''Palaeotherium'' and ''Anoplotherium'' were not found in surface-level deposits but embedded in deeper, harder rock deposits dating to the [[Eocene]]. People in Paris had been previously familiar with animal skeletons being in their area for centuries, some of which were later kept and formally described. However, it was Cuvier who formally erected two fossil genera that came from older deposits, and from his homeland in the continent of Europe instead of the Americas where ''Megatherium'' and ''Mammut'' were found.{{cite book|editor-last1=Chemla|editor-first1=Karine|editor-last2=Keller|editor-first2=Evelyn Fox|last=Belhoste|first=Bruno|year=2017|title=Cultures without Culturalism: The Making of Scientific Knowledge|chapter=Chapter 10: From Quarry to Paper. Cuvier's Three Epistemological Cultures|publisher=Duke University Press|pages=250–277}} The [[Paleogene|Palaeogene]]-aged fossils left no evidence of any later descendants, extinct or extant, although the similarities of ''Palaeotherium'' to tapirs made proving the theory more difficult. He noticed that below the gypsum was older sediments of seashells and reptiles like what Cuvier described as a giant "crocodile", which would later be known as ''[[Mosasaurus]]''. Cuvier knew then that the world that ''Anoplotherium'' and ''Palaeotherium'' came from was a different span of time before that of the preceding time of sea reptiles and the proceeding times of ''Megatherium'' and ''Mammut'', thereby proving the concept of natural extinction.{{cite book|last=Wallace|first=David Rains|year=2004|title=Beasts of Eden: Walking Whales, Dawn Horses, and Other Enigmas of Mammal Evolution|chapter=Chapter 1: Pachyderms in the Catacombs|publisher=University of California Press|pages=1–13}} Cuvier's descriptions of an [[endocast]] (fossilized brain case) of a [[cerebral hemisphere]] belonging to a broken skull of ''A. commune'' from Montmartre, starting from 1804 up to 1822, are recognized as the first true instance of [[paleoneurology|palaeoneurology]], the study of brain evolution. The very first definition of an "endocast" dates back to 1822 when Cuvier described a mould of the brain of ''A. commune'', noticing that it offered hints to the true shape of the brain of the now-extinct mammal (although it was later found to be a portion of the brain rather than the entirety of it). Since the first endocast study, many other brain studies were conducted for other fossil mammals throughout the second half of the 19th century onward.{{cite thesis|last=Allemand|first=Rémi|year=2017|title=Endocranial microtomographic study of marine reptiles (Plesiosauria and Mosasauroidea) from the Turonian (Late Cretaceous) of Morocco: palaeobiological and behavioral implications|type=PhD|publisher=National Museum of Natural History, France|url=https://www.researchgate.net/publication/337484256}}{{cite book|last=Cuvier|first=Georges|year=1822|title=Recherches sur les ossemens fossiles, où l'on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces|trans-title=Researches on Fossil Bones, in which the characteristics of several animals are reconstructed, the species of which were destroyed by the revolutions of the globe|publisher=G. Dufour and E. d'Ocagne|language=french|volume=3|url=https://www.biodiversitylibrary.org/item/214528#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-08-19|archive-url=https://web.archive.org/web/20230819062404/https://www.biodiversitylibrary.org/item/214528#page/1/mode/1up|url-status=live}}{{cite book|editor-last1=Dozo|editor-last2=Paulina-Carabajal|editor-first2=Ariana|editor-last3=Macrini|editor-first3=Thomas E.|editor-last4=Walsh|editor-first4=Stig|last1=Orliac|first1=Maeva J.|last2=Maugoust|first2=Jacob|last3=Balcarcel|first3=Ana|last4=Gilissen|first4=Emmanuel|title=Paleoneurology of Amniotes|date=2023|chapter=Paleoneurology of Artiodactyla, an Overview of the Evolution of the Artiodactyl Brain|publisher=Springer Cham|pages=507–555|doi=10.1007/978-3-031-13983-3_13|isbn=978-3-031-13982-6|chapter-url=https://hal.science/hal-03931359/file/Book_chap_paleoneuro_Orliac.pdf|access-date=2023-08-30|archive-date=2023-08-29|archive-url=https://web.archive.org/web/20230829140545/https://hal.science/hal-03931359/file/Book_chap_paleoneuro_Orliac.pdf|url-status=live}} An 1822 description by Cuvier of a healed fractured femur of ''A. commune'' is cited as an early instance of [[paleopathology|palaeopathology]], the study of ancient diseases and injuries on prehistoric organisms.{{cite journal|last=Moodie|first=Roy Lee|year=1917|title=Studies in Paleopathology. I. General Consideration of Evidence of Pathological Conditions Found among Fossil Animals|journal=Annals of Medical History|volume=1|issue=4|pages=374–393|pmid=33943144|pmc=7927727}}{{cite journal|last1=Diéguez|first1=Carmen|last2=Isidro|first2=Albert|last3=Malgosa|first3=Assumpció|year=1996|title=An introduction to zoo-paleopathology and an update on fossil phyto-paleopathology from Spain|journal=Journal of Paleopathology|volume=8|issue=3|pages=133–142|url=https://www.researchgate.net/publication/281030849}}{{cite book|editor-last1=Buikstra|editor-first1=Jane|editor-last2=Roberts|editor-first2=Charlotte|year=2012|last=Thomas|first=Richard|title=The Global History of Paleopathology: Pioneers and Prospects|chapter=Chapter 66: NonHuman Paleopathology|publisher=Oxford University Press|pages=652–664|doi=10.1093/acprof:osobl/9780195389807.003.0066}} ==== Early depictions ==== {{multiple image | align = left | image1 = Anoplotherium 1812 Skeleton Reconstruction.png | image2 = Anoplotherium_1812_Skeleton_Sketch.jpg | total_width = 500 | footer = Georges Cuvier's published sketch (left) and unpublished sketch with outline (right) of an incomplete skeletal reconstruction of ''Anoplotherium commune'', ~1812. }} In 1812, Cuvier published his drawing of a skeletal reconstruction of ''A. commune'' based on known fossil remains of the species including the aforementioned incomplete skeletons. Based on the robust build of the mammal species, he hypothesized that its body structure was similar to [[otter]]s except for its legs, that it was adapted for semi-aquatic life by swimming for consumption of aquatic plants, lacking long ears similar to semi-aquatic mammals, and living in marshy environments. Cuvier suggested that its lifestyle was therefore similar to semi-aquatic quadrupedal mammals like [[hippopotamuses]] and [[muroid]] rodents. He thought that in comparison, other species of ''Anoplotherium'' such as ''A. medium'' and ''A. minus'' were adapted for terrestrial behaviours and mixed feeding (browsing and grazing).{{cite book|last=Cuvier|first=Georges|year=1812|title=Recherches sur les ossemens fossiles de quadrupèdes: où l'on rétablit les caractères de plusieurs espèces d'animaux que les révolutions du globe paroissent avoir détruites|trans-title=Researches on the Fossil Bones of Quadrupeds: in which the characteristics of several animal species—apparently destroyed by the revolutions of the globe—are reconstructed|chapter=Résumé général et rétablissement des Squelettes des diverses espèces|volume=3|language=french|publisher=Chez Deterville|url=https://www.biodiversitylibrary.org/item/123872#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-07-31|archive-url=https://web.archive.org/web/20230731200748/https://www.biodiversitylibrary.org/item/123872#page/1/mode/1up|url-status=live}}{{cite book|last=Rudwick|first=Martin J. S.|year=1997|title=Georges Cuvier, Fossil Bones, and Geological Catastrophes: New Translations and Interpretations of the Primary Texts|chapter=Chapter 6: The Animals from the Gypsum Beds around Paris|publisher=University of Chicago Press}} Today, the reconstruction for the skeletal anatomy has aged well, mostly standing the test of time since 1812.{{cite journal|last1=Manucci|first1=Fabio|last2=Romano|first2=Marco|year=2022|title=Reviewing the iconography and the central role of 'paleoart': four centuries of geo-palaeontological art|journal=Historical Biology|volume=35|issue=1|pages=1–48|doi=10.1080/08912963.2021.2017919|s2cid=246054069 }} ''Anoplotherium'' and ''Palaeotherium'' were also depicted in 1822 drawings by the French palaeontologist [[Charles Léopold Laurillard]] under the direction of Cuvier, although the restorations were not as detailed as Cuvier's.{{cite book|last=Rudwick|first=Martin J.S.|year=1992|title=Scenes from Deep Time: Early Pictorial Representations of the Prehistoric World|chapter=Chapter 2: Keyholes into the Past|pages=27–58}} [[File:Crystal Palace Anoplotherium.jpg|thumb|Sculptures of an ''Anoplotherium commune'' herd as part of the [[Crystal Palace Dinosaurs]] sculptures on the Tertiary Island of the [[Crystal Palace Park]], United Kingdom]] The reconstruction of ''Anoplotherium'' as an aquatic swimmer was supported by multiple 19th century European palaeontologists and persisted for over a century{{cite book|last=Gervais|first=Paul|year=1848–1852|title=Zoologie et paléontologie françaises (animaux vertébrés): ou nouvelles recherches sur les animaux vivants et fossiles de la France|trans-title=French Zoology and Paleontology (Vertebrate Animals): or New Research on the Living and Fossil Animals of France|chapter=Note sur le genre Eurytherium, suivie d'une liste comparative des Mamifères observés dans les hassins de Paris et d'Apt, et de remarques sur les Ongulés observés en France.|publisher=Arthus Bertrand|language=french|volume=2|url=https://www.biodiversitylibrary.org/item/87545#page/87/mode/1up|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804054414/https://www.biodiversitylibrary.org/item/87545#page/87/mode/1up|url-status=live}}{{cite journal|last1=Schlosser|first1=Max|year=1883|title=Uebersicht der bekannten Anoplotherien und Diplobunen nebst Erläuterung der Beziehungen zwischen Anoplotherium und anderen Säugethierfamilien.|trans-title=Overview of the known Anoplotheres and Diplobunes, together with an explanation of the relationships between Anoplotherium and other mammalian families.|journal=Neues Jahrbuch für Mineralogie, Geologie und Palaeontologie, Abhandlungen|language=french|volume=2|url=https://www.biodiversitylibrary.org/item/151144#page/189/mode/1up|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804211228/https://www.biodiversitylibrary.org/item/151144#page/189/mode/1up|url-status=live}} until 1938 when M. Dor rejected the theory of the genus as being aquatic-adapted based on anatomical differences from otters and hippopotamuses that contradict semi-aquatic behaviours and are more consistent with terrestrial life.{{cite journal|last=Dor|first=M.|year=1938|title=Sur la biologie de l'Anoplotherium (L'Anoplotherium était-il aquatique?)|trans-title=On the biology of Anoplotherium (Was Anoplotherium aquatic?)|journal=Mammalia|language=french|volume=2|pages=43–48|doi=10.1515/mammalia-1938-020108}} This rejection was supported by Jerry J. Hooker in 2007 and Svitozar Davydenko et al. in 2023 based on anatomical traits, although the former disagreed with Dor's observations on the tail. Hooker argued that although the distal caudal vertebrae of the anoplothere are less prominent than those of kangaroos (''[[Macropus]]''), the vertebrae patterns of ''Anoplotherium'' are more similar to ''Macropus'' than ungulates like ''[[Bos]]'' or ''[[Equus (genus)|Equus]]''. Today, ''Anoplotherium'' is thought to be a terrestrial browser with specialized behaviours.{{cite journal|last=Hooker|first=Jerry J.|year=2007|title=Bipedal browsing adaptations of the unusual Late Eocene–earliest Oligocene tylopod Anoplotherium (Artiodactyla, Mammalia)|journal=Zoological Journal of the Linnean Society|volume=151|issue=3|pages=609–659|doi=10.1111/j.1096-3642.2007.00352.x|doi-access=free}}{{cite journal|last1=Davydenko|first1=Svitozar|last2=Gol'din|first2=Pavel|last3=Bosselaers|first3=Mark|last4=Vahldiek|first4=Bernd|last5=Vliet|first5=Henk Jan van|year=2023|title=Gross and microscopic anatomy of a tibia tentatively attributed to a cetacean from the Middle Eocene of Europe, with a note on the artiodactyl Anoplotherium and on the perissodactyl Lophiodon|journal=Paläontologische Zeitschrift|volume=97 |issue=3 |pages=627–652 |doi=10.1007/s12542-023-00653-x|bibcode=2023PalZ...97..627D |s2cid=259897461 }} ''A. commune'' was notably depicted in the [[Crystal Palace Dinosaurs]] attraction in the [[Crystal Palace Park]] in the [[United Kingdom]], open to the public since 1854 and constructed by English sculptor [[Benjamin Waterhouse Hawkins]]. More specifically, three statues of ''A. commune'' were made, two of which are standing and the third of which is in a reposed position. These statues resemble hybrids of deer and [[big cat]]s and measure {{cvt|3.6|m}} long. Its inclusion in the Crystal Palace Park reflects the popularity and public interest in ''Anoplotherium'' in the 19th century, as it was an icon of palaeontology, geology, and natural history that it was regularly incorporated in palaeontological texts and classrooms (its popularity diminished since the 20th century).{{cite book|last1=Phillips|first1=Samuel|last2=Shenton|first2=Francis Kingston John|year=1860|title=Guide to the Crystal Palace and park|url=https://books.google.com/books?id=KiJbAAAAcAAJ|access-date=2023-08-30|archive-date=2023-08-29|archive-url=https://web.archive.org/web/20230829140653/https://books.google.com/books?id=KiJbAAAAcAAJ|url-status=live}}{{cite book|last1=Witton|first1=Mark P.|last2=Michel|first2=Ellinor|year=2022|title=The Art and Science of the Crystal Palace Dinosaurs|chapter=Chapter 4: The sculptures: mammals|publisher=The Crowood Press|pages=68–91}} The sculptures of ''A. commune'' were overall based on Hawkins closely following Cuvier's description of the genus based on known remains, including Cuvier's unpublished robust muscle speculations which are seen as accurate by modern-day standards. Hawkins did also deviate outside of Cuvier's descriptions, however, likely basing its facial designs and the inaccurate presence of tetradactyl limbs (four toes on each foot) instead of didactyl or tridactyl limbs on extant camelids. Besides these errors, the statues have largely been accurate to modern-day depictions of ''Anoplotherium''. ==== Confusions with other mammal groups ==== [[File:Extinct monsters and creatures of other days (6288299303).jpg|thumb|upright=0.8|Illustrations of ''Anoplotherium'' (foreground left), ''Xiphodon'' (background left), and ''Palaeotherium'' (right)]] For much of the 19th century, palaeontologists confused mammals of other families with ''Anoplotherium'' largely due to palaeontology being at its early stages. One of the earlier examples is 1822, when Cuvier erected the names ''A. gracile'', ''A. murinum'', ''A. obliquum'', ''A. leporinum'', and ''A. secundaria'', replacing earlier species names within ''Anoplotherium'' outside of ''A. commune''. In ''A. gracile'', he noticed differences in the [[molar (tooth)|molars]] that he erected the [[subgenus]] ''[[Xiphodon]]''. For ''A. leporinum'', ''A. murinum'', and ''A. obliquum'', the subgenus ''[[Dichobune]]'' was created by Cuvier based on its small size. In 1848, French palaeontologist [[Auguste Pomel]] promoted the 2 subgenera to genus ranks and erected an additional genus ''[[Amphimeryx]]'' for ''A. murinus'' and ''A. obliquus''. The revised taxonomies were followed by subsequent palaeontologists like French naturalist [[Paul Gervais]]. Therefore, the species are no longer classified as ''Anoplotherium'' but distant genera.{{cite journal|last=Pomel|first=Auguste|year=1848|title=Recherches sur les caractères et les rapports entre eux des divers genres vivants et fossiles des Mammifères ongulés|trans-title=Research on the characteristics and interrelationships of the various living and fossil genera of ungulate mammals|journal=Comptes rendus hebdomadaires des séances de l'Académie des sciences|language=french|volume=26|pages=686–688|url=https://www.biodiversitylibrary.org/item/21163#page/696/mode/1up}}{{cite book|last=Gervais|first=Paul|year=1848–1852|title=Zoologie et paléontologie françaises (animaux vertébrés): ou nouvelles recherches sur les animaux vivants et fossiles de la France|trans-title=French Zoology and Paleontology (Vertebrate Animals): or New Research on the Living and Fossil Animals of France|chapter=Diverses espèces d'Ongulés fossiles.|publisher=Arthus Bertrand|language=french|volume=2|url=https://www.biodiversitylibrary.org/item/87545#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804054414/https://www.biodiversitylibrary.org/item/87545#page/1/mode/1up|url-status=live}}{{cite book|last=Lydekker|first=Richard|year=1885|title=Catalogue of the fossil Mammalia in the British museum, (Natural History): Part II. Containing the Order Ungulata, Suborder Artiodactyla|publisher=Order of the Trustees, London|url=https://www.biodiversitylibrary.org/item/125716#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-08-02|archive-url=https://web.archive.org/web/20230802145811/https://www.biodiversitylibrary.org/item/125716#page/1/mode/1up|url-status=live}} Other mammals initially confused with the genus ''Anoplotherium'' but eventually reclassified within the 19th century represented the endemic European artiodactyl family [[Cainotheriidae]] (''[[Cainotherium]]''{{cite book|last=Saint-Hilaire|first=Étienne Geoffroy|year=1833|title=Revue encyclopédique, ou Analyse raisonnée des productions les plus remarquables|trans-title=Encyclopedic Review, or Analytical Survey of the Most Remarkable Works|chapter=Considérations sur ossements fossiles, la plus inconnus, trouvés et observés dans le l'Auvergne|publisher=Bureau Central de la Revue Encyclopédique|language=french|volume=59|url=https://books.google.com/books?id=eGdFAAAAYAAJ|access-date=2023-09-19|archive-date=2023-08-25|archive-url=https://web.archive.org/web/20230825151202/https://books.google.com/books?id=eGdFAAAAYAAJ|url-status=live}}{{cite journal|last=Berthet|first=Didier|year=2003|title=Le genre Cainotherium (Mammalia, Artiodactyla): étude morphométrique, révision systématique, implications évolutives et paléogéographiques, extinction|trans-title=The genus Cainotherium (Mammalia, Artiodactyla): morphometric study, systematic revision, evolutionary and paleogeographic implications, extinction|journal=Travaux et Documents des Laboratoires de Géologie de Lyon|language=french|volume=159|number=159|pages=3–205|url=https://www.persee.fr/doc/geoly_0750-6635_2003_mon_159_1#geoly_0750-6635_2003_mon_159_1_T1_0036_0000|access-date=2023-08-30|archive-date=2023-08-06|archive-url=https://web.archive.org/web/20230806224744/https://www.persee.fr/doc/geoly_0750-6635_2003_mon_159_1#geoly_0750-6635_2003_mon_159_1_T1_0036_0000|url-status=live}}), European and Indian subcontinental members of the perissodactyl family [[Chalicotheriidae]] (''[[Anisodon]]''{{cite journal|last=Lartet|first=Édouard|year=1837|title=Note sur les ossements fossiles des terrains tertiaires de Simorre, de Sansan, etc., dans le département du Gers, et sur la découverte récente d'une mâchoire de singe fossile.|trans-title=Note on the fossil bones from the Tertiary deposits of Simorre, Sansan, etc., in the Department of Gers, and on the recent discovery of a fossil monkey jaw. |journal=Comptes Rendus de l'Académie des Sciences|language=french|volume=4|pages=85–93|url=https://www.biodiversitylibrary.org/item/112006#page/89/mode/1up|access-date=2023-08-30|archive-date=2020-06-13|archive-url=https://web.archive.org/web/20200613221709/https://www.biodiversitylibrary.org/item/112006#page/89/mode/1up|url-status=live}}{{cite journal|last=Lartet|first=Édouard|year=1839|title=Notice géologique.|trans-title=Geological Note.|journal=Extrait de l'Annuaire du Département du Gers|language=french}}{{cite journal|last1=Anquetin|first1=Jérémy|last2=Antoine|first2=Pierre-Olivier|last3=Tassy|first3=Pascal|year=2007|title=Middle Miocene Chalicotheriinae (Mammalia, Perissodactyla) from France, with a discussion on chalicotheriine phylogeny|journal=Zoological Journal of the Linnean Society|volume=151|issue=3|pages=577–608|doi=10.1111/j.1096-3642.2007.00327.x|doi-access=free}} and ''[[Nestoritherium]]''{{cite journal|last1=Cautley|first1=Proby T.|last2=Falconer|first2=Hugh|year=1837|title=Notice on the Remains of a Fossil Monkey from the Tertiary Strata of the Sewalik Hills in the North of Hindoostan.|journal=Transactions of the Geological Society|pages=499–504|url=https://www.biodiversitylibrary.org/item/111770#page/639/mode/1up|access-date=2023-08-30|archive-date=2023-08-02|archive-url=https://web.archive.org/web/20230802183104/https://www.biodiversitylibrary.org/item/111770#page/639/mode/1up|url-status=live}}{{cite book|last=Lydekker|first=Richard|year=1886|title=Catalogue of the fossil Mammalia in the British museum, (Natural History): Part III. Containing the Order Ungulata, Suborders Perissodactyla, Toxondontia, Condylarthra, and Amblypoda|publisher=Order of the Trustees, London|url=https://www.biodiversitylibrary.org/item/125717#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-08-02|archive-url=https://web.archive.org/web/20230802200529/https://www.biodiversitylibrary.org/item/125717#page/1/mode/1up|url-status=live}}{{cite journal|last1=Colbert|first1=Edwin H.|year=1935|title=The Proper Use of the Generic Name Nestoritherium|journal=Journal of Mammalogy|volume=16|issue=3|pages=233–234|doi=10.1093/jmammal/16.3.233}}), and even endemic South American members of the order [[Litopterna]] (''[[Scalabrinitherium]]'' and ''[[Proterotherium]]''{{cite journal|last=Buffetaut|first=Eric|year=2016|title=From Charles Darwin's comments to the first mention of South American giant fossil birds: Auguste Bravard's catalogue of fossil species from Argentina (1860) and its significance|journal=Bulletin de la Société Géologique de France|volume=187|issue=1|pages=41–53|doi=10.2113/gssgfbull.187.1.41}}). ==== Revisions within the Anoplotheriidae ==== [[File:Anoplotherium commune Teylers.JPG|thumb|''A. commune'' jaw fragment, [[Teylers Museum]]]] In 1851, Pomel observed that ''Anoplotherium'' species could be determined as having either didactyl hooves (lessened third index) or tridactyl hooves (greater-developed third index) and that the only previously erected species that are valid are ''A. commune'' and ''A. secundaria''. In addition, he erected three new species based on additional remains: ''A. duvmoyi'' (based on Cuvier's fossil illustrations of ''A. commune''), ''A. platypus'', ''A. laurillardi'' (convex incisors on the anterior surface), and ''A. cuvieri''. ''A. laurillardi'' derives as a species name from Charles Laurillard.{{cite journal|last=Pomel|first=Auguste|year=1851|title=Nouvelles observations sur la structure des pieds dans les animaux de la famille des Anoplotherium, et dans le genre Hyaemoschus.|trans-title=New observations on the structure of the feet in animals of the Anoplotherium family and in the genus Hyaemoschus.|journal=Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences|language=french|volume=33|pages=16–17|url=https://www.biodiversitylibrary.org/item/106907#page/26/mode/1up|access-date=2023-08-30|archive-date=2023-08-03|archive-url=https://web.archive.org/web/20230803201439/https://www.biodiversitylibrary.org/item/106907#page/26/mode/1up|url-status=live}} French palaeontologist Paul Gervais in 1852 named the genus ''Eurytherium'' based on its presence of tridactyl hooves instead of didactyl hooves, for he made the new species ''E. latipis'' the type species and ''A. platypus'' a synonym of the former. [[Henri Filhol]] would follow Gervais by erecting ''E. quercyi'' and ''E. minus'' based on dental sizes and reclassifying ''A. secundarium'' (or ''A. secundaria'') to ''Eurytherium''.{{cite journal|last=Filhol|first=Henri|year=1877|title=Recherches sur les Phosphorites du Quercy. Etude des fossiles qu'on y rencontre et spécialement des mammiféres.|trans-title=Research on the Quercy Phosphorites. A study of the fossils found there, particularly the mammals.|journal=Annales des Sciences Géologiques de Paris|language=french|url=https://gallica.bnf.fr/ark:/12148/bpt6k432584w/f5.item.r=minus|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804211456/https://gallica.bnf.fr/ark:/12148/bpt6k432584w/f5.item.r=minus|url-status=live}} In 1862, [[Ludwig Rütimeyer]] erected the subgenus ''[[Diplobune]]'' for the genus ''Dichobune'' on the basis that it was an evolutionary transition between ''Anoplotherium secundarium'' and the dichobunid.{{cite journal|last=Rütimeyer|first=Ludwig|year=1862|title=Eocaene Säugethiere aus dem Gebiet des schweizerischen Jura.|trans-title=Eocene mammals from the Swiss Jura region.|journal=Neue Denkschriften der Schweizerischen Naturforschenden Gesellschaft|language=german|volume=19|pages=1–98|url=https://www.biodiversitylibrary.org/item/47574#page/1/mode/1up|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804195821/https://www.biodiversitylibrary.org/item/47574#page/1/mode/1up|url-status=live}} It was promoted to a distinct genus with one species ''D. bavaricum'' being placed into the genus by [[Oscar Fraas]] by 1870, however.{{cite journal|last=von Fraas|first=Oscar Friedrich|year=1870|title=Diplobune bavaricum.|journal=Palaeontographica|language=german|volume=17|pages=177–184|url=https://www.biodiversitylibrary.org/item/44253#page/187/mode/1up|access-date=2023-08-30|archive-date=2023-08-04|archive-url=https://web.archive.org/web/20230804195819/https://www.biodiversitylibrary.org/item/44253#page/187/mode/1up|url-status=live}} [[File:Anoplotherium illustrations postcranial remains.jpg|thumb|upright=0.9|Illustrations of the [[calcaneum]], [[astragalus (bone)|astragalus]], and partial [[fibula]] of ''A. commune'']] In 1883, [[Max Schlosser (zoologist)|Max Schlosser]] made ''Eurytherium'' a synonym of ''Anoplotherium'' because he argued that the limb anatomies and dentitions were specific differences in characteristics rather than major ones that defined an entire genus. Sclosser pointed out that all species of ''Anoplotherium'' in some form had three indexes despite ''A. commune'' having less developed third indexes than ''A. latipes''. He also reinforced the idea that "''A. platypus''" is a synonym of ''A. latipes''. The name ''A. latipes'' takes priority over ''A. platypus'' to the modern day because Pomel in 1851 did not list any specimen for the species, effectively making it a [[nomen dubium]]. He also mentioned that the status of ''A. duvmoyi'' was not stable due to being based on illustrations, which he considered to be a "hopeless effort". He also supported ''Diplobune'' being a valid genus in that he argued that ''A. secundaria'' should be renamed to ''D. secundaria'' based on dentition and smaller sizes. Schlosser also said that ''A. cuvieri'' was an invalid species because the diagnosis based on isolated [[metatarsal bone]]s was valid-enough. [[Richard Lydekker]] erected the species ''A. cayluxense'' in 1885 based on its smaller size and unique variations in the molar cusps. He also demoted the genus ''Diplobune'' as a synonym of ''Anoplotherium'', meaning that the former's species were added/readded to ''Anoplotherium'' as ''A. secundarium'', ''A. quercyi'', ''A. modicum'', ''A. bavaricum'', and ''A. minus'' (= ''A. minor'', Filhol 1877). The synonymy of ''Diplobune'' with ''Anoplotherium'' was not supported by [[Hans Georg Stehlin]] in 1910, as he argued that the former was generically distinct from the latter despite their close relations, thus restoring the previous species into ''Diplobune'' (with the exception of ''D. modicum'', which he synonymized with ''D. bavarica'') and adding "''A. secundarium''" into ''Diplobune'' as ''D. secundaria''. He also wrote that ''A. cayluxense'' was a synonym of ''D. secundaria''. Stehlin also tentatively referred "''A.''" ''obliquum'' to the genus ''[[Haplomeryx]]'' as ''H? obliquum''. As a result of the revisions, the only valid species of ''Anoplotherium'' were ''A. commune'', ''A. latipes'', and ''A. laurillardi''.{{cite journal|last=Stehlin|first=Hans Georg|year=1910|title=Die Säugertiere des schweizerischen Eocaens. Sechster Teil: Catodontherium – Dacrytherium – Leptotherium – Anoplotherium – Diplobune – Xiphodon – Pseudamphimeryx – Amphimeryx – Dichodon – Haplomeryx – Tapirulus – Gelocus. Nachträge, Artiodactyla incertae sedis, Schlussbetrachtungen über die Artiodactylen, Nachträge zu den Perissodactylen.|trans-title=The Mammals of the Swiss Eocene. Part Six: Catodontherium – Dacrytherium – Leptotherium – Anoplotherium – Diplobune – Xiphodon – Pseudamphimeryx – Amphimeryx – Dichodon – Haplomeryx – Tapirulus – Gelocus. Addenda, Artiodactyla incertae sedis, concluding remarks on the Artiodactyla, addenda regarding the Perissodactyla.|journal=Abhandlungen der Schweizerischen Paläontologischen Gesellschaft|language=german|volume=36|url=https://www.biodiversitylibrary.org/item/247842#page/5/mode/1up|access-date=2023-08-30|archive-date=2023-08-05|archive-url=https://web.archive.org/web/20230805150136/https://www.biodiversitylibrary.org/item/247842#page/5/mode/1up|url-status=live}} In 1922, German palaeontologist [[Wilhelm Otto Dietrich]] erected the fourth species ''A. pompeckji'' from the locality of [[Mähringen]] in Germany, named in honor of German palaeontologist [[Josef Felix Pompeckj]]. The species was described as a medium-sized tridactyl species with 4-fingered front limbs and 3-toed hind limbs with slimmer hand bone proportions and a smaller [[astragalus (bone)|astragalus]].{{cite journal|last=Dietrich|first=Wilhelm Otto|year=1922|title=Beitrag zur Kenntnis der säugetierführenden Bohnerzformation in Schwaben. 1. Ein vergessenes, neu erschlossenes Höhlenvorkommen terrestrischen Eozäns auf der Ulmer Alb.|trans-title=Contribution to the knowledge of the mammal-bearing pisolitic iron ore formation in Swabia. 1. A forgotten, newly accessible cave deposit of terrestrial Eocene age on the Ulm Alb.|journal=Zentralblatt für Mineralogie, Geologie und Paläontologie|language=german|volume=19|pages=209–224}} ''A. pompeckji'' is the least characterized species and has similar dentition to ''A. laurillardi'', making its status less certain compared to the three other species.{{cite journal|last1=Badiola|first1=Ainara|last2=De Vicuña|first2=Nahia Jiménez|last3=Perales-Gogenola|first3=Leire|last4=Gómez-Olivencia|first4=Asier|year=2023|title=First clear evidence of Anoplotherium (Mammalia, Artiodactyla) in the Iberian Peninsula: an update on the Iberian anoplotheriines|journal=The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology|doi=10.1002/ar.25238|pmid=37221992 |s2cid=258864256 |doi-access=free|pmc=12062563}} In 1964, palaeontologist [[Louis de Bonis]] reviewed briefly the taxonomic synonyms of ''Anoplotherium'', considering that ''A. duvernoyi'' was based on a young individual with incisor characteristics that Pomel did not specify and that ''A. cuvieri'' does not differ in metacarpal dimensions from ''A. laurillardi''. He followed Stehlin in recognizing the three main species of ''Anoplotherium'', although he did not mention ''A. pompeckji'' in his review.{{cite journal|last=de Bonis|first=Louis|year=1964|title=Étude de quelques mammifères du Ludien de La Débruge (Vaucluse)|trans-title=Study of some mammals from the Ludian of La Débruge (Vaucluse)|journal=Annales de Paléontologie|language=french|pages=121–154}} === Classification === [[File:Georges Cuvier.png|thumb|Portrait of [[Georges Cuvier]], the French naturalist who described ''Palaeotherium'' and ''Anoplotherium'' in 1804]] ''Anoplotherium'' is the [[type genus]] of the Anoplotheriidae, a Palaeogene artiodactyl family endemic to western Europe that lived from the Middle Eocene to the Early Oligocene (~44 to 30 Ma, possible earliest record at ~48 Ma). The exact evolutionary origins and dispersals of the anoplotheriids are uncertain, but they exclusively resided within the continent when it was an [[archipelago]] that was isolated by seaway barriers from other regions such as [[Balkanatolia]] and the rest of eastern Eurasia. The Anoplotheriidae's relations with other members of the Artiodactyla are not well-resolved, with some determining it to be either a tylopod (which includes camelids and [[merycoidodont]]s of the Palaeogene) or a close relative to the infraorder and some others believing that it may have been closer to the Ruminantia (which includes [[tragulid]]s and other close Palaeogene relatives).{{cite journal|last1=Licht|first1=Alexis|last2=Métais|first2=Grégoire|last3=Coster|first3=Pauline|last4=İbilioğlu|first4=Deniz|last5=Ocakoğlu|first5=Faruk|last6=Westerweel|first6=Jan|last7=Mueller|first7=Megan|last8=Campbell|first8=Clay|last9=Mattingly|first9=Spencer|last10=Wood|first10=Melissa C.|last11=Beard|first11=K. Christopher|year=2022|title=Balkanatolia: The insular mammalian biogeographic province that partly paved the way to the Grande Coupure|journal=Earth-Science Reviews|volume=226|article-number=103929 |doi=10.1016/j.earscirev.2022.103929|bibcode=2022ESRv..22603929L |doi-access=free}} The Anoplotheriidae consists of two subfamilies, the [[Dacrytheriinae]] and [[Anoplotheriinae]], the latter of which is the younger subfamily that ''Anoplotherium'' belongs to. The Dacrytheriinae is the older subfamily of the two that first appeared in the Middle Eocene (since the [[Mammal Paleogene zones|Mammal Palaeozone Zones]] unit MP13, possibly up to MP10), although some authors consider them to be a separate family in the form of the Dacrytheriidae.{{cite book|editor-last1=Prothero|editor-first1=Donald R.|editor-last2=Foss|editor-first2=Scott E.|last1=Erfurt|first1=Jörg|last2=Métais|first2=Grégoire|year=2007|title=The Evolution of Artiodactyls|publisher=Johns Hopkins University Press|chapter=Endemic European Paleogene Artiodactyls|pages=59–84}}{{cite journal|last1=Orliac|first1=Maeva|last2=Gilissen|first2=Emmanuel|year=2012|title=Virtual endocranial cast of earliest Eocene Diacodexis (Artiodactyla, Mammalia) and morphological diversity of early artiodactyl brains|journal=Proceedings of the Royal Society B|volume=279|issue=1743|pages=3670–3677 |doi=10.1098/rspb.2012.1156|pmid=22764165 |pmc=3415922 }} Anoplotheriines made their first appearances by the Late Eocene (MP15-MP16), or ~41-40 Ma, within western Europe with ''[[Duerotherium]]'' and ''[[Robiatherium]]''. By MP17a-MP17b, however, there is a notable gap in the fossil record of anoplotheriines overall as the former two genera seemingly made their last appearances by the previous MP level MP16.{{cite journal|last1=Cuesta|first1=Miguel-Ángel|last2=Badiola|first2=Ainara|year=2009|title=Duerotherium sudrei gen. et sp. nov., a New Anoplotheriine Artiodactyl from the Middle Eocene of the Iberian Peninsula|journal=Journal of Vertebrate Paleontology|volume=29|number=1|pages=303–308|doi=10.1671/039.029.0110|jstor=20491092|bibcode=2009JVPal..29..303C|s2cid=55546022}} By MP18, ''Anoplotherium'' and ''Diplobune'' made their first appearances in western Europe, but their exact origins are unknown. The two genera were widespread throughout western Europe based on abundant fossil evidence spanning from Portugal, Spain, United Kingdom, France, Germany, and Switzerland for much of pre-Grande Coupure Europe (prior to MP21), meaning that they were typical elements of the Late Eocene up until the earliest Oligocene.{{cite book|last1=Schmidt-Kittler|first1=Norbert|last2=Godinot|first2=Marc|last3=Franzen|first3=Jens L.|last4=Hooker|first4=Jeremy J.|year=1987|chapter=European reference levels and correlation tables|title=Münchner geowissenschaftliche Abhandlungen A10|publisher=Pfeil Verlag, München|pages=13–31|url=https://www.researchgate.net/publication/234056546}} The earlier anoplotheriines are considered to be smaller species whereas the later anoplotheriines were larger. ''Anoplotherium'' and ''Diplobune'' are considered the most [[apomorphy and synapomorphy|derived]] (or evolutionarily recent) anoplotheriids based on dental morphology and achieved gigantism amongst non-[[Whippomorpha|whippomorph]] artiodactyls, making them some of the largest non-whippomorph artiodactyls of the Palaeogene as well as amongst the largest mammals to roam western Europe at the time (all species of ''Anoplotherium'' were large to very large whereas not all species of ''Diplobune'' were large).{{cite journal|last1=Sudre|first1=Jean|last2=Martinez|first2=Jean-Noël|year=1995|title=The astragalus of Paleogene artiodactyls: comparative morphology, variability and prediction of body mass|journal=Lethaia|volume=28|issue=3|pages=197–209|doi=10.1111/j.1502-3931.1995.tb01423.x|bibcode=1995Letha..28..197M }}{{cite thesis|last=Weppe|first=Romain|year=2022|title=Déclin des artiodactyles endémiques européens, autopsie d'une extinction|trans-title=Decline of endemic European artiodactyls: an autopsy of an extinction|language=french|publisher=University of Montpellier|url=https://theses.hal.science/tel-04160245|access-date=2023-08-30|archive-date=2023-08-11|archive-url=https://web.archive.org/web/20230811141229/https://theses.hal.science/tel-04160245|url-status=live}} [[File:Cainotherium restoration.jpg|thumb|left|Reconstructed skeleton of the related ''[[Cainotherium]]'']] Conducting studies focused on the phylogenetic relations within the Anoplotheriidae has proven difficult due to the general scarcity of fossil specimens of most genera. The phylogenetic relations of the Anoplotheriidae as well as the [[Xiphodontidae]], [[Mixtotheriidae]], and Cainotheriidae have also been elusive due to the [[selenodont]] morphologies of the molars, which were convergent with tylopods or ruminants. Some researchers considered the selenodont families Anoplotheriidae, Xiphodontidae, and Cainotheriidae to be within Tylopoda due to postcranial features that were similar to the tylopods from North America in the Palaeogene. Other researchers tie them as being more closely related to ruminants than tylopods based on dental morphology. Different phylogenetic analyses have produced different results for the "derived" selenodont Eocene European artiodactyl families, making it uncertain whether they were closer to the Tylopoda or Ruminantia.{{cite journal|last1=Luccisano|first1=Vincent|last2=Sudre|first2=Jean|last3=Lihoreau|first3=Fabrice|year=2020|title=Revision of the Eocene artiodactyls (Mammalia, Placentalia) from Aumelas and Saint-Martin-de-Londres (Montpellier limestones, Hérault, France) questions the early European artiodactyl radiation|journal=Journal of Systematic Palaeontology|volume=18|issue=19|pages=1631–1656|doi=10.1080/14772019.2020.1799253|bibcode=2020JSPal..18.1631L |s2cid=221468663 }}{{cite journal|last1=Weppe|first1=Romain|last2=Blondel|first2=Cécile|last3=Vianey-Liaud|first3=Monique|last4=Escarguel|first4=Gilles|last5=Pélissié|first5=Thierry|last6=Antoine|first6=Pierre-Olivier|last7=Orliac|first7=Maëva Judith|year=2020|title=Cainotheriidae (Mammalia, Artiodactyla) from Dams (Quercy, SW France): phylogenetic relationships and evolution around the Eocene–Oligocene transition (MP19–MP21)|journal=Journal of Systematic Palaeontology|volume=18|number=7|pages=541–572|doi=10.1080/14772019.2019.1645754|bibcode=2020JSPal..18..541W|s2cid=202026238|url=https://hal.archives-ouvertes.fr/hal-02349546/file/caino_manuscrit_Review2.pdf|access-date=2023-09-19|archive-date=2022-03-07|archive-url=https://web.archive.org/web/20220307180222/https://hal.archives-ouvertes.fr/hal-02349546/file/caino_manuscrit_Review2.pdf|url-status=live}} In an article published in 2019, Romain Weppe et al. conducted a phylogenetic analysis on the [[Cainotherioidea]] within the Artiodactyla based on mandibular and dental characteristics, specifically in terms of relationships with artiodactyls of the Palaeogene. The results retrieved that the superfamily was closely related to the Mixtotheriidae and Anoplotheriidae. They determined that the Cainotheriidae, [[Robiacinidae]], Anoplotheriidae, and Mixtotheriidae formed a clade that was the sister group to the Ruminantia while Tylopoda, along with the [[Amphimerycidae]] and Xiphodontidae split earlier in the tree. The phylogenetic tree used for the journal and another published work about the cainotherioids is outlined below:{{cite journal|last1=Weppe|first1=Romain|last2=Blondel|first2=Cécile|last3=Vianey-Liaud|first3=Monique|last4=Pélissié|first4=Thierry|last5=Orliac|first5=Maëva Judith|year=2020|title=A new Cainotherioidea (Mammalia, Artiodactyla) from Palembert (Quercy, SW France): Phylogenetic relationships and evolutionary history of the dental pattern of Cainotheriidae|journal=Palaeontologia Electronica|number=23(3):a54|doi=10.26879/1081|s2cid=229490410 |doi-access=free}} {{clade| style=font-size:85%; line-height:85% |1={{clade |1=''[[Eurodexis|Eurodexis russelli]]'' |2=''[[Dichobune|Dichobune leporina]]'' |3={{clade |1={{clade |1=''[[Amphimeryx|Amphimeryx murinus]]'' |2={{clade |1=''[[Xiphodon|Xiphodon castrense]]'' |label2=[[Tylopoda]] |2={{clade |1=''[[Paratoceras|Paratoceras coatesi]]'' |2=''[[Eotylopus|Eotylopus reedi]]''}}}}}} |2={{clade |label1=[[Ruminantia]] |1={{clade |1=''[[Parvitragulus|Parvitragulus priscus]]'' |2={{clade |1=''[[Lophiomeryx|Lophiomeryx chalaniati]]'' |2=''[[Archaeomeryx|Archaeomeryx optatus]]''}}}} |2={{clade |label1=[[Mixtotheriidae]] |1=''[[Mixtotherium|Mixtotherium cuspidatum]]'' |label2=[[Anoplotheriidae]] |2={{clade |1='''''Anoplotherium latipes''''' |2=''[[Dacrytherium|Dacrytherium ovinum]]''}} |label3=[[Cainotherioidea]] |3={{clade |label1=[[Robiacinidae]] |1={{clade |1=''[[Robiacina|Robiacina lavergnesis]]'' |2={{clade |1=''[[Robiacina|Robiacina minuta]]'' |2=''[[Robiacina|Robiacina quercyi]]''}}}} |label2=[[Cainotheriidae]] |2={{clade |1=''[[Palembertina|Palembertina deplasi]]'' |2={{clade |label1=[[Oxacroninae]] |1={{clade |1=''[[Paroxacron|Paroxacron bergeri]]'' |2={{clade |1=''[[Paroxacron|Paroxacron valdense]]'' |2=''[[Oxacron|Oxacron courtoisii]]''}}}} |label2=[[Cainotheriinae]] |2={{clade |1=''[[Cainotherium|Cainotherium laticurvatum]]'' |2={{clade |label1=''[[Caenomeryx]]'' |1={{clade |1=''[[Caenomeryx|Caenomeryx filholi]]'' |2=''[[Caenomeryx|Caenomeryx procommunis]]''}} |label2=''[[Plesiomeryx]]'' |2={{clade |1=''[[Plesiomeryx|Plesiomeryx cadurcensis]]'' |2=''[[Plesiomeryx|Plesiomeryx huerzeleri]]''}}}}}}}}}}}}}}}}}}}}}} In 2020, Vincent Luccisano et al. created a phylogenetic tree of the basal artiodactyls, a majority endemic to western Europe, from the Palaeogene. In one clade, the "bunoselenodont endemic European" Mixtotheriidae, Anoplotheriidae, Xiphodontidae, Amphimerycidae, Cainotheriidae, and Robiacinidae are grouped together with the Ruminantia. The phylogenetic tree as produced by the authors is shown below: {{clade| style=font-size:85%; line-height:85% |label1=[[Artiodactyla]] |1={{clade |label2= |1=''[[Bunophorus]]'' |2={{clade |1=''[[Gunophorus]]'' |2=''[[Diacodexis]]'' }} |3={{clade |1={{clade |1=''[[Protodichobune]]'' |2=''[[Eurodexis]]'' }} |2={{clade |1={{clade |1=''[[Buxobune]]'' |2={{clade |1=''[[Mouillacitherium]]'' |2=''[[Meniscodon]]'' }} |3={{clade |1={{clade |1=''[[Hyperdichobune]]'' |2={{clade |1=''[[Dichobune|Dichobune robertiana]]'' |2={{clade |1=''[[Dichobune|Dichobune leporina]]'' |2={{clade |1=''[[Homacodon]]'' |2={{clade |label2=[[Suina]] |1=''[[Gobiohyus]]'' |2={{clade |1={{clade |1=''[[Khirtharia]]'' |2=''[[Entelodon]]'' }} |2={{clade |1=''[[Palaeocheorus]]'' |2=''[[Perchoerus]]'' }} }} }} }} }} }} }} |2={{clade |label1=[[Haplobunodontidae]] |1={{clade |1=''[[Haplobunodon]]'' |2={{clade |1=''[[Cuisitherium]]'' |2=''[[Lophiobunodon]]'' }} }} |2={{clade |1=''[[Mixtotherium]]'' |2={{clade |1=''[[Robiacina]]'' |2={{clade |1={{clade |1={{clade |1=''[[Dacrytherium]]'' |2=''[[Diplobune]]'' }} |2={{clade |1=''[[Xiphodon]]'' |2=''[[Paraxiphodon]]'' }} }} |2={{clade |1={{clade |1=''[[Cainotherium]]'' |2=''[[Paroxacron]]'' }} |2={{clade |1=''[[Archaeomeryx]]'' |2={{clade |1=''[[Amphimeryx]]'' |2=''[[Pseudamphimeryx]]'' }} }} }} }} }} }} }} }} }} |2={{clade |1=''[[Aumelasia]]'' |2={{clade |1={{clade |1=''[[Hallebune]]'' |2=''[[Amphirhagatherium]]'' }} |2={{clade |label1=[[Cebochoeridae]] |1={{clade |1=''[[Cebochoerus]]'' |2=''[[Gervachoerus]]'' }} |2={{clade |1=''[[Choeropotamus]]'' |2=''[[Siamotherium]]'' }} }} }} }} }} }} }} }} In 2022, Weppe created a phylogenetic analysis in his academic [[thesis]] regarding Palaeogene artiodactyl lineages, focusing most specifically on the endemic European families. The phylogenetic tree, according to Weppe, is the first to conduct phylogenetic affinities of all anoplotheriid genera, although not all individual species were included. He found that the Anoplotheriidae, Mixtotheriidae, and Cainotherioidea form a clade based on [[apomorphy and synapomorphy|synapomorphic]] dental traits (traits thought to have originated from their most recent common ancestor). The result, Weppe mentioned, matches up with previous phylogenetic analyses on the Cainotherioidea with other endemic European Palaeogene artiodactyls that support the families as a clade. As a result, he argued that the proposed superfamily Anoplotherioidea, composing of the Anoplotheriidae and Xiphodontidae as proposed by Alan W. Gentry and Hooker in 1988, is invalid due to the [[polyphyly]] of the lineages in the phylogenetic analysis. However, the Xiphodontidae was still found to compose part of a wider clade with the three other groups. ''Anoplotherium'' and ''Diplobune'' compose a clade of the Anoplotheriidae because of their derived dental traits, supported by them being the latest-appearing anoplotheriids.{{cite book|last1=Gentry|first1=Alan W.|last2=Hooker|first2=Jerry J.|year=1988|title=The Phylogeny and Classification of the Tetrapods: Volume 2: Mammals (The Systematics Association Special Volume, No. 35B)|chapter=The phylogeny of the Artiodactyla|publisher=Oxford University Press|pages=235–272}} == Description == === Size === [[File:Anoplotherium size comparison chart.png|thumb|Estimated ''Anoplotherium'' size comparisons based on known fossil material]] ''Anoplotherium'' species were particularly large in the Late Eocene, reaching sizes unusual for most artiodactyl groups in the Palaeogene. The large size estimates began in 1995 when Martinez and Sudre made weight estimates of Palaeogene artiodactyls based on the dimensions of their astragali and M1 teeth. The astragali are common bones in fossil assemblages due to their reduced vulnerability to fragmentation as a result of their stocky shape and compact structure, explaining their choice for using it. The two measurements for ''A. commune'' yielded different results, with the M1 giving the body mass of {{cvt|312.075|kg}} and the astragalus yielding {{cvt|265.967|kg}}. These estimates are far larger than those of most other Palaeogene artiodactyls in the study, although the researchers pointed out that the M1 measurements could be overestimated compared to the astragalus estimate. In 2014, Takehisa Tsubamoto reexamined the relationship between astragalus size and estimated body mass based on extensive studies of extant terrestrial mammals, reapplying the methods to Palaeogene artiodactyls previously tested by Sudre and Martinez. The researcher used linear measurements and their products with adjusted correction factors. The recalculations resulted in somewhat lower estimates compared to the 1995 results (with the exception of ''Diplobune minor'', which as a shorter astragalus proportion than most other artiodactyls), displayed in the below graph:{{cite journal |last=Tsubamoto |first=Takehisa |year=2014 |title=Estimating body mass from the astragalus in mammals |journal=Acta Palaeontologica Polonica |volume=59 |issue=2 |pages=259–265 |doi=10.4202/app.2011.0067 |s2cid=54686160 |doi-access=free}} [[File:Body Mass Estimates European Paleogene Artiodactyls.jpg|thumb|center|Estimated body masses (kg) of Palaeogene artiodactyls based on recalculated trochlear widths (Li1) in comparison to estimates from Martinez and Sudre (1995)]] In 2022, Weppe calculated the body mass of ''A. commune'', yielding {{cvt|360|kg}}. In 2023, Ainara Badiola et al. estimated that the weight of ''Anoplotherium'' ranges between {{cvt|115|kg}} and {{cvt|271|kg}}. In their calculations, ''A. laurillardi'' was the smaller anoplotheriid that weighed on average {{cvt|157|kg}}. ''A. latipes'' was larger and has an average weight estimate of {{cvt|229|kg}}, and ''A. commune'' has the heaviest weight estimates at {{cvt|271|kg}}. In 2007, Hooker made size estimates of ''A. latipes'' based on an incomplete skeleton of an immature individual from the Hamstead Member of the [[Bouldnor Formation]] in the [[Isle of Wight]], United Kingdom. The reconstructed Hamstead level 3 individual gave size measurements of {{cvt|2|m}} in head and body length. The immature ''Anoplotherium'' individual's humerus measures {{cvt|330|mm}} long, so the humeri of mature individuals may have measured about {{cvt|410|mm}} long. As a result, adult ''A. latipes'' may have measured {{cvt|2.5|m}} in head and body length and {{cvt|1.25|m}} in shoulder height. When standing up bipedally on its hind limbs with the back, neck and head at an angle of about 15°, the Hamstead level 3 individual might have reached {{cvt|2.5|m}} when browsing while more mature ''A. latipes'' individuals might have stood just over {{cvt|3|m}}. === Skull === [[File:Anoplotherium commune skull.JPG|thumb|Upper part of the skull of ''Anoplotherium commune'', [[National Museum of Natural History, France]]]] The Anoplotheriidae is characterized in part by low-proportioned skulls with elongated [[muzzle (anatomy)|muzzles]] (the muzzle aligns with the top of the [[cranium]] in the case of ''Anoplotherium''), and orbits that are widely open from behind.{{cite book|last=von Zittel|first=Karl Alfred|editor-last=Schlosser|editor-first=Max|year=1925|title=Text-Book of Paleontology. Volume III. Mammalia|publisher=Macmillan and Co. Limited|pages=179–180|url=https://www.biodiversitylibrary.org/item/125078#page/191/mode/1up|access-date=2023-08-30|archive-date=2023-08-14|archive-url=https://web.archive.org/web/20230814154524/https://www.biodiversitylibrary.org/item/125078#page/191/mode/1up|url-status=live}}{{cite book|editor-last1=Harmer|editor-first1=Sidney Frederic|editor-last2=Shipley|editor-first2=Arthur Everett|last=Beddard|first=Frank Evers|year=1902|title=The Cambridge Natural History: Mammalia|publisher=Macmillan and Co. Limited|pages=332–333|url=https://www.biodiversitylibrary.org/item/280573#page/348/mode/1up|access-date=2023-08-30|archive-date=2023-08-17|archive-url=https://web.archive.org/web/20230817023815/https://www.biodiversitylibrary.org/item/280573#page/348/mode/1up|url-status=live}} The skull's upper profile is straight and nearly transversely flat from the parietal bones of the skull's back to the front area of the nasals; this trait along with another of the orbit being above the second upper molar (M2) is shared with ''Diplobune''.{{cite journal|last=Depéret|first=Charles|year=1906|title=Los vertebrados del obligoceno inferior de Tárrega|trans-title=Vertebrates from the Lower Oligocene of Tárrega|journal=Memorias de la Real Academia de Ciencias y Artes de Barcelona|language=spanish|series=3|volume=5|pages=401–451|url=https://www.biodiversitylibrary.org/item/245521#page/527/mode/1up}}{{cite journal|last=Sudre|first=Jean|year=1974|title=D'important restes de Diplobune minor Filhol à Itardies (Quercy)|journal=Palaeovertebrata|volume=6|pages=47–54|url=https://palaeovertebrata.com/Articles/view/167}} Anoplotheriids have large paroccipital processes, formed from the mastoid and [[lateral parts of occipital bone|exoccipital]] bones. ''Anoplotherium'' lacks [[fossa for lacrimal sac|lacrimal fossa]]e unlike in dacrytheriines.{{cite book|last=Viret|first=Jean|year=1961|title=Traitè de Palèontologie|section=Artiodactyla|publisher=Masson|pages=887–1104}} The skull of ''Anoplotherium'' is narrow and elongated, with a constricted postorbital bone. It features robust [[sagittal crest|sagittal]] and [[nuchal lines]], the former having high elevations and emerging from low postorbital ridges and the latter having complicated elevation shifts. The back has a circular foramen magnum and large [[occipital condyle]]s. The [[lambdoid]] crest is well-developed and large. The underside has an elongated [[palate]] with glenoid surfaces and strong glenoid processes of the [[squamosal bone]].{{cite journal|last=Palmer|first=R.W.|year=1913|title=The Brain and Brain-Case of a Fossil Ungulate of the Genus Anoplotherium|journal=Proceedings of the Zoological Society of London|volume=83|number=4|pages=878–893|doi=10.1111/j.1096-3642.1913.tb01994.x|url=https://www.biodiversitylibrary.org/part/72259|access-date=2023-09-19|archive-date=2023-10-13|archive-url=https://web.archive.org/web/20231013195726/https://www.biodiversitylibrary.org/part/72259|url-status=live}} The skull's bones are robust, with the spongy [[diploë]] bone being greatly developed. The skull's strength is attributed to massive [[temporal muscles]] as part of an overall strong body build. The skull has a shallow [[pituitary fossa|sella turcica]], a pear-shaped [[cranial fossa]], extensive [[parietal bone]]s, large squamosal bone, narrow [[occipital bone]], and two small [[occipital bun]]s for muscle attachment. Many cranial traits seen in ''Anoplotherium'' are also found in the closely related ''Diplobune''.{{cite journal|last1=Pearson|first1=Helga Sharpe|year=1927|title=On the Skulls of Early Tertiary Suidae, together with an Account of the Otic Region in Some Other Primitive Artiodactyla|journal=Philosophical Transactions of the Royal Society of London. Series B, Containing Papers of a Biological Character|volume=215|issue=421–430 |pages=440–445|doi=10.1098/rstb.1927.0009|doi-access=free}} The nuchal lines of the occipital bone are prominent, overhanging at the skull's back. The [[zygomatic arch]] is overall straight and, at its rear, is oblique. ''Anoplotherium'' also has a narrow postglenoid process at the [[temporal bone]] and a strong and elongated [[jugular process]] at the occipital bone.{{cite journal|last1=Remy|first1=Jean A.|last2=Fournier|first2=François|year=2003|title=Mammifères fossiles des grès de Célas (Eocène supérieur du Gard): découvertes récentes|trans-title=Fossil mammals from the Célas Sandstones (Upper Eocene, Gard): recent discoveries|journal=Bulletin de la Société d'étude des sciences naturelles de Nîmes|language=french|volume=64|pages=18–30|url=https://www.researchgate.net/publication/262669532_Mammiferes_fossiles_des_gres_de_Celas_Eocene_superieur_du_Gard_decouvertes_recentes}} In the auditory region (including the temporal bones), the [[periotic bone]] of the inner ear is extensive, the [[internal auditory meatus]] and [[facial canal]] openings of the temporal bone being visible in the lower triangular area of the periotic bone. The [[tympanic part of the temporal bone]] is connected partially to the squamosal bone, remains separate from the periotic bone, and consists of a small but thick auditory bulla (hollow bony structure of the auditory region), which projects underneath the [[petrous part of the temporal bone]]. The mandible is elongated, its lower edge being nearly straight. The [[angle of the mandible]] is prominent and rounded. The [[coronoid process of the mandible]] is strong. In a skull fragment of ''A. laurillardi'' with incisors and canine [[alveolar process|alveoli]], the known length of the [[nasal bone|nasal]] region is large, measuring {{cvt|38.1|mm}}. The trait of large nasals is similar to what was observed in a skull of ''Diplobune secundaria'', which are recorded to be massive, elongated, and connected to each other and the [[maxilla]]. Cyril Gagnaison and Jean-Jacques Leroux proposed in the case of ''D. secundaria'' that the elongated nasal region supports the presence of a very tapered tongue, which similar to [[giraffe]]s may have allowed it to pull plant branches.{{cite journal|last1=Gagnaison|first1=Cyril|last2=Leroux |first2=Jean-Jacques|year=2013|title=Un crâne de Diplobune secundaria Cuvier, 1822 de Saint-Capraise-d'Eymet (Dordogne)|trans-title=A skull of Diplobune secundaria Cuvier, 1822 from Saint-Capraise-d'Eymet (Dordogne)|language=french|journal=Symbioses|volume=29|pages=43–46|url=https://www.researchgate.net/publication/279186555}} === Endocast anatomy === {{multiple image | align = left | image1 = Anoplotherium brain cast dorsal view.png | image2 = Anoplotherium brain cast ventral view.png | total_width = 300 | footer = Illustrations of a brain cast of ''Anoplotherium'' in dorsal (top) and ventral (botton) views, 1913 }} In 1913, R.W. Palmer conducted studies on the brain cast from a cranium of ''Anoplotherium commune'', originating from the [[Quercy Phosphorites Formation|Phosphorites of Quercy]] within the [[British Museum]] collections (the endocast is now in the [[National Museum of Natural History, France]] as the specimen BMNH 3753). The individual in question was estimated to have weighed {{cvt|80|kg}} by its death similar to extant [[llama]]s, weighing considerably less than typical estimates of adult ''Anoplotherium''. The total length of the brain is under {{cvt|10|cm}}, its volume measuring approximately {{cvt|230|ml}}.{{cite book|editor-last1=Kass|editor-first1=Jon H.|editor-last2=Striedter|editor-first2=Georg F.|editor-last3=Rubenstein|editor-first3=John L.R.|editor-last4=Bullock|editor-first4=Theodore H.|editor-last5=Krubitzer|editor-first5=Leah|editor-last6=Preuss|editor-first6=Todd|last=Jerison|first=Harry J.|year=2009|title=Evolutionary Neuroscience|chapter=Chapter 10: How Can Fossils Tell us About the Evolution of the Neocortex?|publisher=Academic Press|pages=497–508}} The form of the brain is naturally narrow and elongated. The cerebellum and cerebrum are both at high positions compared to modern ungulates that have brain hemispheres located above the cerebellum. Palmer noticed that the brain was similar to the modern [[aardvark]] (''Orycteropus afer''). The highly-developed cerebrum that enables a strong sense of smell from ''Anoplotherium'' makes it macrosmatic (derived in sense of smell), as also indicated by the enlarged olfactory bulbs and the small size of the [[neocortex]]. In both ''Anoplotherium'' and ''Diplobune'', the [[rhinal fissure]] divides the brain hemisphere horizontally and equally in half. The [[cerebellar vermis]] of the cerebellum is divided almost equally by the [[primary fissure of cerebellum]] (or "fissura prima").{{cite book|last=Edinger|first=Tilly|title=25: Evolution of the Horse Brain|year=1948|chapter=Evolution of the Horse Brain|series=Geological Society of America Memoirs|volume=25|pages=1–178|publisher=Geological Society of America|chapter-url=https://books.google.com/books?id=KXhH_mLYyNEC&pg=PR1|doi=10.1130/MEM25-p1|access-date=2023-09-19|archive-date=2023-10-13|archive-url=https://web.archive.org/web/20231013195725/https://books.google.com/books?id=KXhH_mLYyNEC&pg=PR1|url-status=live}} Additionally, the [[olfactory bulbs]] are thick, and the [[olfactory tubercles]] take the form of smooth circular elevations that are curved more backwards than the aardvark and are easily noticeable. In another endocast for ''Anoplotherium'', the olfactory bulbs compose 7.5% of the total volume of the brain, above average for both extinct and extant artiodactyls. The [[neocortex]] area of the brain, responsible for [[sensory perception]] and other sensory brain functions, covers 28% of the medium-sized ''A. commune'' endocast's surface area. Another endocast, which belongs to ''Anoplotherium'' sp., measures {{cvt|7173.92|mm}}2 in the cerebrum surface, {{cvt|4419.56|mm}}2 in neopallium surface, and {{cvt|416.09|cm}}3 in endocranial volume. The former two data when calculated together (neopallium surface/cerebrum surface) compose 61.6% in the total neocortical surface area of the brain, meaning that adult ''Anoplotherium'' has massive brain and neocortical surface area measurements compared to most Palaeogene artiodactyls, the latter measurement being on par with or less than those of modern artiodactyls. ''Anoplotherium'' and other anoplotheriids share traits of generally elongated and parallel [[sulcus (neuroanatomy)|sulci]] (shallow furrows) in the [[cerebral cortex]], as well as a vertical (cordial) sulcus corresponding to the lateral (side) sulcus. The fissures (deep furrows) on the surface of the central area of the brain show clear formations of a complex [[lateral sulcus]] (also known as the Sylvian fissure) in a process known as operculization. The operculization of the brain of anoplotheriids is similar to the [[Anthracotheriidae]] but does not indicate any close phylogenetic relation, which means that the similarities are an instance of [[parallel evolution]]. The measurements of the endocasts of ''Anoplotherium'' are larger than those of other Palaeogene artiodactyls in a 2015 study by Ghislain Thiery and Stéphane Ducrocq.{{cite journal|last1=Thiery|first1=Ghislain|last2=Ducrocq|first2=Stéphane|year=2015|title=Endocasts and brain evolution in Anthracotheriidae (Artiodactyla, Hippopotamoidea)|journal=Journal of Anatomy|volume=227|issue=3|pages=277–285|doi=10.1111/joa.12348|pmid=26278931 |pmc=4560562 }} === Dentition === [[File:Anoplotherium laurillardi 43.jpg|thumb|left|''Anoplotherium laurillardi'' lower dental remains, [[Natural History Museum of Basel]]]] Unlike most mammal fossil genera, ''Anoplotherium'' is diagnosed mainly based on postcranial morphology than dental morphology, but it does have diagnoses based on the latter. The [[dental formula]] of ''Anoplotherium'' and other anoplotheriids is {{DentalFormula|upper=3.1.4.3|lower=3.1.4.3}} for a total of 44 teeth, consistent with the primitive dental formula for early-middle Palaeogene [[placental]] mammals.{{cite journal|last1=Lihoreau|first1=Fabrice|last2=Boisserie|first2=Jean-Renaud|last3=Viriot|first3=Laurent|last4=Brunet|first4=Michel|year=2006|title=Anthracothere dental anatomy reveals a late Miocene Chado-Libyan bioprovince|journal=Proceedings of the National Academy of Sciences|volume=103|issue=23|pages=8763–8767 |doi=10.1073/pnas.0603126103 |pmid=16723392 |pmc=1482652 |bibcode=2006PNAS..103.8763L |doi-access=free }} Anoplotheriids have selenodont (crescent-shaped ridge form) or bunoselenodont (bunodont and selenodont) [[premolar]]s (P/p) and [[molar (tooth)|molars]] (M/m) made for leaf-browsing diets. The [[canine tooth|canines]] (C/c) of the Anoplotheriidae are overall undifferentiated from the [[incisor]]s (I/i). The lower premolars of the family are piercing and elongated. The upper molars are bunoselenodont in form while the lower molars have selenodont labial [[cusp (anatomy)|cuspids]] and bunodont (or rounded) lingual cuspids. The subfamily Anoplotheriinae differs from the Dacrytheriinae by the lack of both molariform upper premolars with crescent-shaped paraconules and the lower molars with a third cusp between the metaconid and entoconid. The upper molars of ''Anoplotherium'' are characterized by trapezoidal outlines in occlusal views (or top views of the tooth enamel), W-shaped ectolophs (crests or ridges of upper molar teeth), and specific differences in cusps. More specifically, the upper molars of the genus contain near-central and conical protocone cusps closely aligned with the mesostyle cusps, conical paraconules that are connected to the parastyle by posterior crests, and compressed parastyles and mesostyles. The lower molars of the anoplotheriid contains the paraconid and metaconid cusps which have pronounced separations by a valley between them. === Vertebrae and ribs === [[File:Anoplotherium commune coda montmartre.JPG|thumb|upright=0.34|''A. commune'' tail, NMHN, France]] ''Anoplotherium'' has 7 total [[cervical vertebrae]] for a series of C1-C7, typical of most mammals. The [[atlas (anatomy)|atlas]] (C1) is similar to those of camelids such as ''[[Lama (genus)|Lama]]'' in form as well as the position of the "alar foramina" in association with [[facet joint]] connections involving the [[axis (anatomy)|axis]] (C2). An axis that was attributed to ''A. commune'' (but also possibly belonging to its close relative ''Diplobune secundaria'') is elongated in length and has a diminished spinous process. The vertebrae C3-C7 are analogous to ''Cainotherium''. The C4 vertebra appears slanted, which hints towards the neck changing in orientation from vertebra C3 to C4 as a potential bending in the front area of the neck, similar to modern bears. As a result of the neck vertebrae morphology, ''Anoplotherium'' likely had a sloped, upward position of the neck. ''Anoplotherium'' also had 12 [[thoracic vertebrae]], 6 lumbar vertebrae, and 3 sacral vertebrae. The lumbar vertebrae, especially L4-L6, contain transverse processes that are wide, long, and point slightly towards a forward direction. The 3 sacral vertebrae are robust and contain [[process (anatomy)|apophyses]] for strong attachments to the long tail. The vertebrae of the anoplotheriid genus are built for typical ungulate movement. The most unusual postcranial aspect of ''Anoplotherium'' compared to other artiodactyls is the long and thick tail, which is made up of 22 caudal vertebrae for strong muscle support. The frontal vertebrae had well-pronounced process, and all vertebrae except for the farthest distal ones have [[haemal arch]]es on them. Like the chalicothere ''[[Chalicotherium]]'' and unlike other mammals like [[Caprinae|caprine]]s of the genus ''[[Ovis]]'' and ''Cainotherium'', the ribs curve in wider areas and their tubercles do not project as much in the dorsal direction. The ribs of ''Anoplotherium'' form a barrel-shaped trunk, meaning that the rib cage is much wider than those of modern ruminants. The ribs generally project sideways due to the very curved positions of them, the position of the tubercle, and the thoracic vertebrae projecting on the upper sides. === Limbs === ''Anoplotherium'' has short limbs and is thought to have been [[unguligrade]] in limb positions, with most species having three toes on both their front and hind limbs. ''A. commune'' is differentiated from the similar ''A. latipes'' as well as ''A. laurillardi'' by its didactyl ("two-toed") as opposed to tridactyl ("three-toed") digits.{{cite conference|last=Métais|first=Grégoire|year=2014|conference=Swiss Geoscience Meeting 2014|title=On the "thumb" of anoplotheriins: a 3D comparative study of the hand of Anoplotherium and Diplobune|url=https://www.researchgate.net/publication/309036785}} ==== Front limbs ==== [[File:Anoplotherium commune pes.JPG|thumb|upright=0.5|Foot of ''A. commune'' at the National Museum of Natural History, France]] The [[scapula]] (or shoulder blade) has a convex [[coracoid process|coracoid]] border and is similar to that of ''Diplobune''. Similar to camels (''Camelus''), the [[supraspinous fossa]] is broader than the [[infraspinous fossa]], but camels have narrower scapulae, especially in distal (back) ends of the supraspinous fossa. The [[scapular spine]] is robust, thick, and gradually rises in height distally up until it reaches the edge of the glenoid cavities like camels but unlike most other modern artiodactyls. The coracoid process (normally resembling a small hooklike structure) is reduced to a blunt knob that only slightly projects. The wide supraspinous fossa and broadly curved coracoid edge of the scapulae of ''Anoplotherium'' are unlike ''Cainotherium'' and ''[[Merycoidodon]]'' because ''Anoplotherium'' shares neither any triangular shape of the shoulder blades nor narrow supraspinous fossae. The elbow morphology of ''Anoplotherium'', based on the structures and articulations of elbow bones like the [[humerus]], [[radius]], and [[ulna]], shows evidence of adaptations to moving the elbow up and down in supination-pronation rotations by 13° maximum. A fully extended elbow could make an angle between the ulna and humerus that measures approximately 135°, indicating high flexibility compared to other artiodactyls, including the already semi-flexible elbows of ''Cainotherium''. Similar in wrist morphology to pigs of the genus ''[[Sus (genus)|Sus]]'', the hooves of ''Anoplotherium'' spread out by ~16° when downward, supported by footprint morphology. The wrist may have been able to rotate up and down but only to a limited degree and nowhere near the flexible wrist morphologies of primates, suggesting that the adaptation was not a main feature of the artiodactyl genus but the result of regaining a primitive trait. The carpus consists of the [[scaphoid bone|scaphoid]], [[lunate bone|lunate]], [[triquetrum bone|triquetrum]], and [[pisiform bone|pisiform]] in its first row and the [[trapezium bone|trapezium]], [[trapezoid bone|trapezoid]], [[capitate bone|capitate]], and [[hamate bone|hamate]] in its second. ''Anoplotherium'' has four digit bones, but those of digit V and, in the case of ''A. commune'', digit II are poorly developed.{{cite journal|last=Abusch-Siewert|first=Susanne|year=1989|title=Bemerkungen zu den Anoplotherien (Artiodactyla, Mammalia) der Pariser Gipse|journal=Münchner Geowissenschaftliche Abhandlungen A|volume=15|pages=55–78}} The second finger (digit II) of ''Anoplotherium'' has no capability of rotation or flexible movements, which signifies that it does not play any thumb-like role like in primates or the [[giant panda]]. ==== Hind limbs ==== [[File:Anoplotherium commune 1.jpg|thumb|upright=0.55|''A. commune'' foot, Teylers Museum]] The [[Ilium (bone)|ilium]], part of the [[hip bone]] of the greater [[pelvis]] bone, is broad and has a firmly rounded [[iliac crest]] that meets with the concave underside edge at a sharp angle. The ilium of ''Anoplotherium'' can be differentiated from ''Palaeotherium'' by the shorter iliac body, the longer [[ischium]] (the lower and back area of the hip bone), and a straighter back edge of pelvis that results in a longer [[pubic symphysis]]. The [[acetabular fossa]] region of the [[acetabulum]] surface of the pelvis is large, its [[acetabular notch]] being in a posterior (or back) position similar to that in ''Chalicotherium''. The femur is larger than the [[tibia]], has only two trochanters similar to other basal artiodactyls, has a narrow gap between its [[femoral head]] and [[greater trochanter]], and has a long [[femoral neck]]. The [[trochanteric fossa]], a hollow at the surface of the greater trochanter, is wide in depth and narrow in shape, deepening by the sides. The tibia is robust, strongly supporting muscle attachments based on its crests and processes. The distal end of the [[fibula]] plus the medial [[malleolus]] prominence of the tibia enclose the center area of the astragalus in order to prevent it from moving sideways. Anoplotheriids with known postcranial fossils have proportionally wide, stocky, and oblique astragali (or talus or ankle bone), differing widely from other artiodactyls. ''A. latipes'' differs from ''A. commune'' in part by morphologies of the facets plus fossae of the astragalus and a shorter and more robust [[calcaneum]] (heel bone). The astragali of anoplotheres share levels of elevations and positions of specific facets with the merycoidodonts that no modern artiodactyls share, possibly an instance of [[convergent evolution]].{{cite journal|last=Heissig|first=Kurt|year=1993|title=The Astragalus in Anoplotheres and Oreodonts, Phylogenetical and Paleogeographical Implications|journal=Kaupia|volume=3|pages=173–178}}{{cite book|editor-last1=Prothero|editor-first1=Donald R.|editor-last2=Foss|editor-first2=Scott E.|year=2007|title=The Evolution of Artiodactyls|publisher=Johns Hopkins University Press|chapter=Summary|page=307}} The medial (sustentacular) facet of ''Anoplotherium'' and ''Diplobune'' is concave, contrasting with the flat to slightly convex facet of ''[[Dacrytherium]]''. The tarsus consists of the navicular, three cueniform bones, and a cuboid bone. The foot of ''A. commune'' consisted of two toes, as indicated by the relatively small outermost and middle cuneiform bones. === Footprints === Large-sized footprints from southern France and north Spain that date to the Late Eocene{{cite journal|last1=de Carvalho|first1=Carlos Neto|last2=Muñiz|first2=Fernando|last3=Cáceres|first3=Luis M.|last4=Belaústegui|first4=Zain|last5=Rodríguez-Vidal|first5=Joaquín|last6=Belo|first6=João|last7=Moreira|first7=Noel|last8=Cachão|first8=Mário|last9=Cunha|first9=Pedro P.|last10=Figueiredo|first10=Silvério|last11=Galán|first11=José María|last12=Zhang|first12=Yilu|last13=Gómez|first13=Paula|last14=Toscano|first14=Antonio|last15=Ruiz|first15=Francisco|last16=Ramírez-Cruzado|first16=Samuel|last17=Giles-Guzmán|first17=Francisco|last18=Finlayson|first18=Geraldine|last19=Finlayson|first19=Stewart|last20=Finlayson|first20=Clive|display-authors=10|year=2022|title=Aurochs roamed along the SW coast of Andalusia (Spain) during Late Pleistocene|journal=Scientific Reports|volume=12|number=9911|page=9911 |doi=10.1038/s41598-022-14137-6 |doi-access=free|pmid=35701579 |pmc=9198092 |bibcode=2022NatSR..12.9911D }} may have been from ''Anoplotherium''. The [[ichnogenus]] is named ''[[Anoplotheriipus]]'' and was first described from the department of [[Gard]] in France by Paul Ellenberger in 1980. The derivation of the genus name refers to the ichnotaxon being closest in affinity to the Anoplotheriidae. The ichnogenus is diagnosed as belonging to a very large artiodactyl, the [[limb development|autopod]] area exceeding that of ''A. commune'' by ~33%, the subparallel position of the two hooves, and the posterior area of the pedal sole being as transversely wide as the anterior area of the pedal sole.{{cite journal|last=Ellenberger|first=Paul|year=1980|title=Sur les empreintes de pas des gros mammifères de l'Eocène supérieur de Garrigues-ste-Eulalie (Gard)|trans-title=On the footprints of large mammals from the Upper Eocene of Garrigues-Sainte-Eulalie (Gard)|journal=Palaeovertebrata|language=french|volume=9|pages=37–78|url=https://palaeovertebrata.com/articles/view/293|access-date=2023-08-30|archive-date=2023-08-29|archive-url=https://web.archive.org/web/20230829153847/https://palaeovertebrata.com/articles/view/293|url-status=live}} ''Anoplotheriipus'' is round to rectangular in shape with broad and anteriorly-pronounced cloven digit imprints that resemble poorly-preserved camel tracks.{{cite book|editor-last1=Lucas|editor-first1=Spencer G.|editor-last2=Spielmann|editor-first2=Justin A.|editor-last3=Lockley|editor-first3=Martin G.|last1=Lucas|first1=Spencer G.|last2=Hunt|first2=Adrian P.|year=2007|title=Cenozoic Vertebrate Tracks and Traces: Bulletin 42|chapter=Ichnotaxonomy of Camel Footprints|publisher=New Mexico Museum of Natural History and Science|url=https://www.researchgate.net/publication/281862348}} The similar artiodactyl ichnogenus ''[[Diplartiopus]]'' differs from it by the parallelism of the two fingers that are more elongated.{{cite thesis|last=Montes|first=Martín Linares|year=2020|title=Paleontología e interpretación medioambiental de las icnitas de mamíferos del yacimiento de Fondota (Paleógeno, Abiego, Huesca)|trans-title=Paleontology and environmental interpretation of mammal footprints from the Fondota site (Paleogene, Abiego, Huesca)|publisher=University of Zaragoza|language=spanish|url=https://zaguan.unizar.es/record/97900/files/TAZ-TFG-2020-3587.pdf?version=1|access-date=2023-08-30|archive-date=2023-10-19|archive-url=https://web.archive.org/web/20231019205958/https://zaguan.unizar.es/record/97900/files/TAZ-TFG-2020-3587.pdf?version=1|url-status=live}} The type species is ''Anoplotheriipus lavocati'', which Ellenberger named in honor of palaeontologist [[René Lavocat]] and considered the "most majestic" of the three ichnospecies due to the displayed specific mobility of the metatarsals. It measures {{cvt|170|mm}} to {{cvt|180|mm}} in length and {{cvt|120|mm}} in width, is stocky in shape, and measures 12° in toe divergence. The two fingers are nearly equal in length and, at minimum, measure {{cvt|115|mm}} without the metatarsal bones being taken into account and {{cvt|225|mm}} with the metatarsals. The measurements are considerably higher than typical measurements of the toes of ''A. commune'', which are {{cvt|85|mm}} without the metatarsals and {{cvt|170|mm}} with. ''Anoplotheriipus similicommunis'', deriving in species etymology from "similis" (similar in Latin) and ''A. commune'', is similar to the type ichnospecies but is smaller, corresponding more directly to typical foot measurements of ''A. commune'' by its length of {{cvt|140|mm}} and width of {{cvt|105|mm}}. The angle of divergence between the two main toes is 10°, and the minimum lengths of the fingers are {{cvt|90|mm}} without the metatarsals and {{cvt|180|mm}} with. ''Anoplotheriipus compactus'' is the third ichnospecies, which in species etymology derives from the Latin word "compactus" meaning "compact" in English due to the short and rounded autopod. It has a less definitive diagnosis compared to the other two ichnotaxa but is similar in size to ''A. similicommunis'' and has a nearly circular pedal sole for supporting slightly shorter fingers. Its length is {{cvt|120|mm}} while the width is {{cvt|100|mm}}, and the finger lengths measure {{cvt|70|mm}} - {{cvt|80|mm}} without the metatarsals and {{cvt|140|mm}} - {{cvt|150|mm}} with. The footprints may have been produced by ''A. latipes'' although the answer is still uncertain. == Palaeobiology == [[File:Anoplotherium commune quadrupedal.png|thumb|Reconstruction of ''A. commune'' in a quadrupedal position]] Since 2007, ''Anoplotherium'' is thought to have been a quadruped that could have stood on its hind legs as a bipedal browser thanks to the strong pelvis, long and robust tail for balance, and splayed hind legs. The bipedal adaptations show some instance of convergence with other animals like chalicotheres, various genera of [[ground sloth]]s, giant pandas (''[[Ailuropoda]] melanoleuca''), [[gorilla]]s (''Gorilla''), and the [[gerenuk]] (''Litocranius walleri''). Otherwise, the general body form appears to resemble those of the [[Canidae]]. As a result of the bend C3-C4 cervical vertebrae, the neck and head could have maintained horizontal orientations while standing bipedally. The forelimbs could have extended horizontally beyond the snout while the individual stood bipedally, although it could not have reached upward and did not have claws or prehensile organs on the [[manus (anatomy)|manus]] unlike ''Chalicotherium''. Therefore, the forearms may have not been used for ripping and tearing plants but as bipedal support. It may have browsed while standing up at a steep angle more comparable to the gerenuk than to ''Chalicotherium''. Its large size and ability to bipedally browse may have given ''Anoplotherium'' few sources of terrestrial competition other than from ''Palaeotherium magnum'', a large-sized [[palaeothere]] with a long neck that may have reached {{cvt|240.3|kg}} in body mass.{{cite journal|last1=MacLaren|first1=Jamie Alexander|last2=Nauwelaerts|first2=Sandra|year=2020|title=Modern Tapirs as Morphofunctional Analogues for Locomotion in Endemic Eocene European Perissodactyls|journal=Journal of Mammalian Evolution|volume=27|issue=2 |pages=245–263|doi=10.1007/s10914-019-09460-1|hdl=10067/1580640151162165141 |s2cid=254703475 |url=https://repository.uantwerpen.be/docman/irua/718476/158064_2020_02_19.pdf |hdl-access=free}} The subspecies ''P. magnum magnum'' would have reached just over {{cvt|2|m}} in browsing height in quadruped stance, and there is no evidence for any bipedal adaptation in palaeotheres. ''Anoplotherium'' likely engaged in degrees of [[niche partitioning]] with the Late Eocene palaeotheres and ''Diplobune''. While all were folivorous browsers, the palaeotheres ''[[Plagiolophus (mammal)|Plagiolophus]]'' and ''Palaeotherium'' may have had small degrees of frugivory while ''Diplobune'' was likely adapted to [[arboreal locomotion|arborealism]].{{cite conference|last1=Joomun|first1=Sarah C.|last2=Hooker|first2=Jerry J.|last3=Collinson|first3=Margaret E.|year=2009|title=Differences in the Dietary Responses of the Perissodactyl ''Plagiolophus'' and the Artiodactyl ''Diplobune'' to the Eocene/Oligocene Transition Events in Europe|conference=69th Annual Meeting Society of Vertebrate Paleontology and the 57th Symposium of Vertebrate Palaeontology and Comparative Anatomy (SVPCA)|volume=29|url=https://vertpaleo.org/wp-content/uploads/2021/03/SVP09AbstractsFULL_WEB.pdf|access-date=2023-08-30|archive-date=2023-05-31|archive-url=https://web.archive.org/web/20230531220412/https://vertpaleo.org/wp-content/uploads/2021/03/SVP09AbstractsFULL_WEB.pdf|url-status=live}}{{cite journal|last1=Joomun|first1=Sarah C.|last2=Hooker|first2=Jerry J.|last3=Collinson|first3=Margaret E.|year=2010|title=Changes in Dental Wear of Plagiolophus Minor (Mammalia: Perissodactyla) Across the Eocene-Oligocene Transition|journal=Journal of Vertebrate Paleontology|volume=30|number=2|pages=563–576|doi=10.1080/02724631003618124|jstor=40666176|bibcode=2010JVPal..30..563J|s2cid=86429890}} How well-adapted ''Anoplotherium'' was to abrasive leaves and drier but still subhumid conditions in the Late Eocene is not well-known and requires future research in dentition for answers. [[File:Anoplotherium commune standing.png|thumb|left|Reconstruction of ''A. commune'' in a bipedal position, most likely to browse on taller vegetation]] Hooker proposed the possibility that the didactyl ''A. commune'' and tridactyl ''A. latipes'' may have been sexual dimorphs of the same species (in which ''A. latipes'' would be a synonym of ''A. commune''). There are little consistent differences in dental morphology between the two species, with any small differences potentially accounting for individual variations. The differences in toe number between the species may have reflected ''A. latipes'' being three-toed and ''A. commune'' being two-toed. The palaeontologist explained that while there is no evidence for the extra digit touching the ground while the individual was walking, the extra digit of ''A. latipes'' may have served as extra balance while browsing bipedally. The third digit might have also served as part of sparring in [[intraspecific competition]] between male individuals. However, he noted that despite the apparent "advantage" of ''A. latipes'' in bipedal browsing, there is no evidence of sexual differences in dietary behaviours or preferences. In addition, both species are found in the same localities of Bouldnor in the United Kingdom plus La Débruge and Montmartre in France, that although ''A. latipes'' is more common in La Débruge than Montmartre, this may be the results of behavioural and/or taphonomic factors. Grégoire Métais expressed being unconvinced that the third toe of ''A. latipes'' is a sexually dimorphic adaptation for bipedal browsing, instead suggesting that they were used in male sparring if ''A. latipes'' and ''A. commune'' were sexual dimorphs. Some evidence of the morphologies of ''Anoplotherium'' have been criticized by some sources. In their study of the morphology of the gerenuk that allows for bipedal, researchers Matt Cartmill and Kaye Brown argued that several postcranial features that were supposedly adaptations of ''Litocranius'' and other bipedal genera does not distinguish the gerenuk from other bovids.{{cite book|editor-last1=Marom|editor-first1=Assaf|editor-last2=Hovers|editor-first2=Erella|last1=Cartmill|first1=Matt|last2=Brown|first2=Kaye|year=2017|title=Human Paleontology and Prehistory|chapter=Posture, Locomotion and Bipedality: The Case of the Gerenuk (Litocranius walleri)|publisher=Springer, Cham|series=Vertebrate Paleobiology and Paleoanthropology|pages=53–70|doi=10.1007/978-3-319-46646-0_6|isbn=978-3-319-46644-6 }} Ciaran Clark et al. (including J.J. Hooker) found from micro-[[CT scans]] that ''Anoplotherium'' being a [[facultative bipedalism|facultative bipedal]] browser was not supported by the [[trabecula]]r architecture of the proximal area of the femur. This may have been the result of poor data results from the micro-CT scans and the smaller sample size, which higher-contrast micro-CT data may better answer in postural information.{{cite conference|last1=Clark|first1=Ciaran|last2=Janis|first2=Christine M.|last3=Hooker|first3=Jerry J.|last4=Rayfield|first4=Emily J.|year=2018|title=Posture in the fossil record: can bone microstructure be used to more accurately reconstruct past behaviour?|conference=The Palaeontological Association: 62nd Annual Meeting; 14th–17th December 2018; University of Bristol|page=72|url=https://www.palass.org/sites/default/files/media/annual_meetings/2018/programme_abstracts_2018.pdf|access-date=2023-08-30|archive-date=2022-06-18|archive-url=https://web.archive.org/web/20220618073541/https://www.palass.org/sites/default/files/media/annual_meetings/2018/programme_abstracts_2018.pdf|url-status=live}} The footprint track patterns of ''Anoplotheriipus'' suggest that ''Anoplotherium'' walked in very similar movement speeds as each other. Based on groupings of the footprint ichnotaxon within the locality of Fondota in the municipality of [[Abiego]] in Spain, ''Anoplotherium'' may have commonly walked in small groups which may imply some gregarious (or sociable) behaviour.{{cite journal|last1=Linares Montes|first1=Martín|last2=Canudo|first2=José Ignacio|last3=Luzón|first3=María Aránzazu|last4=Castanera|first4=Diego|year=2021|title=Un excepcional registro paleoicnológico de artiodáctilos en el Oligoceno inferior de Abiego (Huesca, España)|trans-title= An exceptional artiodactyl paleoichnological record from the Early Oligocene of Abiego (Huesca, Spain)|language=Spanish|journal=Comunicações Geológicas|volume=108|pages=103–107|doi=10.34637/6f8b-cj24|url=https://www.lneg.pt/wp-content/uploads/2022/03/17-Linares-et-al_ER_SM.pdf|access-date=2023-08-30|archive-date=2023-08-29|archive-url=https://web.archive.org/web/20230829141113/https://www.lneg.pt/wp-content/uploads/2022/03/17-Linares-et-al_ER_SM.pdf|url-status=live}} == Palaeoecology == {{further|Mammal Palaeogene zones}} === Early pre–Grande Coupure Europe === [[File:Middle Eocene Paleogeography Tethys Dispersals.jpg|thumb|left|[[Palaeogeography]] of Europe and Asia during the Middle Eocene with possible artiodactyl and perissodactyl dispersal routes.]] For much of the Eocene, a [[greenhouse effect|hothouse climate]] with humid, tropical environments with consistently high precipitations prevailed. Modern mammalian orders including the Perissodactyla, Artiodactyla, and [[Primates]] (or the suborder Euprimates) appeared already by the Early Eocene, diversifying rapidly and developing dentitions specialized for folivory. The [[omnivorous]] forms mostly either switched to folivorous diets or went extinct by the Middle Eocene (47–37 million years ago) along with the archaic "[[condylarths]]". By the Late Eocene (approx. 37–33 mya), most of the ungulate form dentitions shifted from bunodont (or rounded) cusps to cutting ridges (i.e. lophs) for folivorous diets.{{cite journal|last1=Eronen|first1=Jussi T.|last2=Janis|first2=Christine M.|last3=Chamberlain|first3=Charles Page|last4=Mulch|first4=Andreas|year=2015|title=Mountain uplift explains differences in Palaeogene patterns of mammalian evolution and extinction between North America and Europe|journal=Proceedings of the Royal Society B|volume=282|number=1809|doi=10.1098/rspb.2015.0136|pmid=26041349 |pmc=4590438 }}{{cite journal|last=Maitre|first=Elodie|year=2014|title=Western European middle Eocene to early Oligocene Chiroptera: systematics, phylogeny and palaeoecology based on new material from the Quercy (France)|journal=[[Swiss Journal of Palaeontology]]|volume=133|issue=2 |pages=141–242|doi=10.1007/s13358-014-0069-3|s2cid=84066785 |doi-access=free|bibcode=2014SwJP..133..141M }} Land connections between western Europe and North America were interrupted around 53 Ma. From the Early Eocene up until the [[Grande Coupure]] extinction event (56–33.9 mya), western Eurasia was separated into three landmasses: western Europe (an archipelago), Balkanatolia (in-between the [[Paratethys Sea]] of the north and the [[Neotethys Ocean]] of the south), and eastern Eurasia. The [[Holarctic]] mammalian faunas of western Europe were therefore mostly isolated from other landmasses including Greenland, Africa, and eastern Eurasia, allowing for endemism to develop. Therefore, the European mammals of the Late Eocene (MP17–MP20 of the Mammal Palaeogene zones) were mostly descendants of endemic Middle Eocene groups.{{cite journal|last1=Badiola|first1=Ainara|last2=Perales-Gogenola|first2=Leire|last3=Astibia|first3=Humberto|last4=Suberbiola|first4=Xabier Pereda|year=2022|title=A synthesis of Eocene equoids (Perissodactyla, Mammalia) from the Iberian Peninsula: new signs of endemism|journal=Historical Biology|volume=34|issue=8|pages=1623–1631|doi=10.1080/08912963.2022.2060098|bibcode=2022HBio...34.1623B |s2cid=248164842 }} The appearances of derived anoplotheriines by MP18 occurred long after the extinction of the endemic European perissodactyl family [[Lophiodontidae]] in MP16, including the largest lophiodont ''[[Lophiodon]] lautricense'', likely the result of a shift from humid and highly tropical environments to drier and more temperate forests with open areas and more abrasive vegetation. The surviving herbivorous faunas shifted their dentitions and dietary strategies accordingly to adapt.{{cite journal|last1=Robinet|first1=Céline|last2=Remy|first2=Jean Albert|last3=Laurent|first3=Yves|last4=Danilo|first4=Laure|last5=Lihoreau|first5=Fabrice|year=2015|title=A new genus of Lophiodontidae (Perissodactyla, Mammalia) from the early Eocene of La Borie (Southern France) and the origin of the genus Lophiodon Cuvier, 1822|journal=Geobios|volume=48|issue=1|pages=25–38|doi=10.1016/j.geobios.2014.11.003|bibcode=2015Geobi..48...25R }}{{cite journal|last1=Perales-Gogenola|first1=Leire|last2=Badiola|first2=Ainara|last3=Gómez-Olivencia|first3=Asier|last4=Pereda-Suberbiola|first4=Xabier|year=2022|title=A remarkable new paleotheriid (Mammalia) in the endemic Iberian Eocene perissodactyl fauna|journal=Journal of Vertebrate Paleontology|volume=42|issue=4|doi=10.1080/02724634.2023.2189447|bibcode=2022JVPal..42E9447P |s2cid=258663753 }} The environments were still subhumid and full of subtropical evergreen forests, however. The Palaeotheriidae was the sole remaining European perissodactyl group, and frugivorous-folivorous or purely folivorous artiodactyls became the dominant group in western Europe.{{cite journal|last1=Solé|first1=Floréal|last2=Fischer|first2=Valentin|last3=Le Verger|first3=Kévin|last4=Mennecart|first4=Bastien|last5=Speijer|first5=Robert P.|last6=Peigné|first6=Stéphane|last7=Smith|first7=Thierry|year=2022|title=Evolution of European carnivorous mammal assemblages through the Paleogene|journal=Biological Journal of the Linnean Society|volume=135|issue=4|pages=734–753|doi=10.1093/biolinnean/blac002}}{{cite journal|last=Blondel|first=Cécile|year=2001|title=The Eocene-Oligocene ungulates from Western Europe and their environment|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=168|issue=1–2|pages=125–139|doi=10.1016/S0031-0182(00)00252-2|bibcode=2001PPP...168..125B|url=http://doc.rero.ch/record/20314/files/PAL_E4294.pdf|access-date=2023-08-30|archive-date=2017-08-22|archive-url=https://web.archive.org/web/20170822051127/http://doc.rero.ch/record/20314/files/PAL_E4294.pdf|url-status=live}} MP16 also marked the last appearances of most European [[crocodylomorphs]], of which the [[Alligatoroidea|alligatoroid]] ''[[Diplocynodon]]'' was the only survivor due to seemingly adapting to the general decline of tropical climates of the Late Eocene.{{cite journal|last1=Martin|first1=Jeremy E.|last2=Pochat-Cottilloux|first2=Yohan |last3=Laurent|first3=Yves|last4=Perrier|first4=Vincent|last5=Robert|first5=Emmanuel|last6=Antoine|first6=Pierre-Olivier|year=2022|title=Anatomy and phylogeny of an exceptionally large sebecid (Crocodylomorpha) from the middle Eocene of southern France|journal=Journal of Vertebrate Paleontology|volume=42|issue=4|doi=10.1080/02724634.2023.2193828|bibcode=2022JVPal..42E3828M |s2cid=258361595 }}{{cite journal|last=Martin|first=Jeremy E.|year=2015|title=A sebecosuchian in a middle Eocene karst with comments on the dorsal shield in Crocodylomorpha|journal=Acta Palaeontologica Polonica|volume=60|issue=3|pages=673–680|doi=10.4202/app.00072.2014|s2cid=54002673 |doi-access=free}}{{cite journal|last=Antunes|first=Miguel Telles|year=2003|title=Lower Paleogene Crocodilians from Silveirinha, Portugal|journal=Palaeovenebrata|pages=1–26|volume=32|url=https://palaeovertebrata.com/articles/keyword/476|access-date=2023-08-30|archive-date=2023-08-29|archive-url=https://web.archive.org/web/20230829023922/https://palaeovertebrata.com/articles/keyword/476|url-status=live}} === Late Eocene === [[File:Paleotherium magnum.jpg|thumb|left|Restoration of ''[[Palaeotherium]] magnum'', which coexisted with ''Anoplotherium'']] After a considerable gap in anoplotheriine fossils in MP17a and MP17b, the derived anoplotheriines ''Anoplotherium'' and ''Diplobune'' made their first known appearances in the MP18 unit. They were exclusive to the western European archipelago, but their exact origins and dispersal routes are unknown. By then, ''Anoplotherium'' and ''Diplobune'' lived in Central Europe (then an island) and the Iberian Peninsula, only the former genus of which later dispersed into southern England by MP19 due to the apparent lack of ocean barriers. Whereas ''A. latipes'' and ''A. commune'' had temporal ranges lasting from MP18 up to MP21, ''A. laurillardi'' was recorded from MP18 to MP20 and ''A. pompeckji'' from MP19 to MP21.{{cite journal|last1=Kocsis|first1=László|last2=Ozsvárt|first2=Péter|last3=Becker|first3=Damien|last4=Ziegler|first4=Reinhard|last5=Scherler|first5=Laureline|last6=Vlad|first6=Codrea A.|year=2014|title=Orogeny forced terrestrial climate variation during the late Eocene–early Oligocene in Europe|journal=Geology|volume=42|issue=8|pages=727–730|doi=10.1130/G35673.1|bibcode=2014Geo....42..727K|url=http://doc.rero.ch/record/211134/files/PAL_E4388.pdf|access-date=2023-09-19|archive-date=2017-09-21|archive-url=https://web.archive.org/web/20170921221259/http://doc.rero.ch/record/211134/files/PAL_E4388.pdf|url-status=live}} ''Anoplotherium'' coexisted with a wide diversity of artiodactyls in western Europe by MP18, ranging from the more widespread [[Dichobunidae]], [[Tapirulidae]], and Anthracotheriidae to many other endemic families consisting of the Xiphodontidae, [[Choeropotamidae]], [[Cebochoeridae]], [[Amphimerycidae]], and Cainotheriidae.{{cite journal|last1=Bai|first1=Bin|last2=Wang|first2=Yuan-Qing|last3=Theodor|first3=Jessica M.|last4=Meng|first4=Jin|year=2023|title=Small artiodactyls with tapir-like teeth from the middle Eocene of the Erlian Basin, Inner Mongolia, China|journal=Frontiers in Earth Science|volume=11|pages=1–20|doi=10.3389/feart.2023.1117911 |bibcode=2023FrEaS..1117911B |doi-access=free }}{{cite journal|last1=Kostopoulos|first1=Dimitris S.|last2=Koufos|first2=George D.|last3=Christanis|first3=Kimon|year=2012|title=On some anthracotheriid (Artiodactyla, Mammalia) remains from northern Greece: comments on the palaeozoogeography and phylogeny of Elomeryx|journal=[[Swiss Journal of Palaeontology]]|volume=131|issue=2 |pages=303–315|doi=10.1007/s13358-012-0041-z|bibcode=2012SwJP..131..303K |s2cid=195363034}} ''Anoplotherium'' also coexisted with the Palaeotheriidae, the remaining perissodactyl family of western Europe. Late Eocene European groups of the clade [[Ferae]] represented predominantly the [[Hyaenodonta]] ([[Hyaenodontinae]], [[Hyainailourinae]], and [[Proviverrinae]]) but also contained [[Carnivoramorpha]] ([[Miacidae]]) and [[Carnivora]] (small-sized [[Amphicyonidae]]). Other mammal groups present in the Late Eocene of western Europe represented the [[leptictida]]ns ([[Pseudorhyncocyonidae]]),{{cite journal|last=Hooker|first=Jerry J.|year=2013|title=Origin and evolution of the Pseudorhyncocyonidae, a European Paleogene family of insectivorous placental mammals|journal=Palaeontology|volume=56|issue=4|pages=807–835|doi=10.1111/pala.12018|bibcode=2013Palgy..56..807H |s2cid=84322086 |doi-access=free}} primates ([[Adapoidea]] and [[Omomyoidea]]),{{cite journal|last1=Marigó|first1=Judit|last2=Susanna|first2=Ivette|last3=Minwer-Barakat|first3=Raef|last4=Malapeira|first4=Joan Madurell|last5=Moyà-Solà|first5=Salvador|last6=Casanovas-Vilar|first6=Isaac|last7=Gimenez|first7=Jose Maria Robles|last8=Alba|first8=David M.|year=2014|title=The primate fossil record in the Iberian Peninsula|journal=Journal of Iberian Geology|volume=40|issue=1|pages=179–211|doi=10.5209/rev_JIGE.2014.v40.n1.44094|doi-access=free}} [[eulipotyphla]]ns ([[Nyctitheriidae]]),{{cite journal|last1=Manz|first1=Carly|last2=Bloch|first2=Jonathan Ivan|year=2014|title=Systematics and Phylogeny of Paleocene-Eocene Nyctitheriidae (Mammalia, Eulipotyphla?) with Description of a new Species from the Late Paleocene of the Clarks Fork Basin, Wyoming, USA|journal=Journal of Mammalian Evolution|volume=22|issue=3 |pages=307–342|doi=10.1007/s10914-014-9284-3|s2cid=254704409 }} [[chiroptera]]ns, [[Herpetotheriidae|herpetotheriid]]s,{{cite journal|last1=Badiola|first1=Ainara|last2=Cuesta|first2=Miguel-Ángel|year=2006|title=Los marsupiales del yacimiento del Eoceno Superior de Zambrana (Álava, Región Vasco-Cantábrica)|journal=Estudios Geológicos|language=spanish|volume=62|issue=1|pages=349–358|doi=10.3989/egeol.0662130|doi-access=free}} [[apatotheria]]ns,{{cite journal|last=Sigé|first=Bernard|year=1997|title=Les mammiféres insectivoresdes nouvelles collections de Sossís et sites associes (Éocène supérieur, Espagne)|journal=Geobios|volume=30|issue=1|pages=91–113|doi=10.1016/S0016-6995(97)80260-4|bibcode=1997Geobi..30...91S }} and endemic [[rodent]]s ([[Pseudosciuridae]], [[Theridomyidae]], and [[Gliridae]]).{{cite book|last=Dawson|first=Mary R.|year=2003|chapter=Paleogene rodents of Eurasia|title=Distribution and migration of tertiary mammals in Eurasia.|volume=10|pages=97–127}} The alligatoroid ''Diplocynodon'', present only in Europe since the upper Paleocene, coexisted with pre-Grande Coupure faunas as well.{{cite journal|last1=Chroust|first1=Milan|last2=Mazuch|first2=Martin|last3=Luján|first3=Àngel Hernández|year=2019|title=New crocodilian material from the Eocene-Oligocene transition of the NW Bohemia (Czech Republic): an updated fossil record in Central Europe during the Grande Coupure|journal=Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen|volume=293|issue=1|pages=73–82|doi=10.1127/njgpa/2019/0832|s2cid=199104151 }} In addition to snakes, frogs, and [[Salamandridae|salamandrids]], rich assemblage of lizards are known in western Europe as well from MP16-MP20, representing the [[Iguanidae]], [[Lacertidae]], [[Gekkonidae]], [[Agamidae]], [[Scincidae]], [[Helodermatidae]], and [[Varanoidea]].{{cite journal|last=Rage|first=Jean-Claude|year=2012|title=Amphibians and squamates in the Eocene of Europe: what do they tell us?|journal=Palaeobiodiversity and Palaeoenvironments|volume=92|issue=4 |pages=445–457|doi=10.1007/s12549-012-0087-3|bibcode=2012PdPe...92..445R |s2cid=128651937 }} In the MP18 locality of Zambrana in Spain, ''A. laurillardi'' and ''A.'' sp. remains were found with undetermined frog and squamate groups, alligatoroid ''Diplocynodon'', the herpetotheriid ''[[Peratherium]]'', rodents (''[[Theridomys]]'', ''[[Elfomys]]'', ''[[Pseudoltinomys]]'', ''[[Remys]]''), omomyid ''[[Microchoerus]]'', carnivoraformes ''[[Quercygale]]'' and ''[[Paramiacis]]'', dichobunid ''Dichobune'', xiphodonts '' Xiphodon'' and ''Haplomeryx'', and palaeotheres (''Palaeotherium'', ''[[Leptolophus]]'', ''[[Iberolophus]]'', ''[[Pachynolophus]]'', ''[[Paranchilophus]]'').{{cite journal|last1=Minwer-Barakat|first1=Raef|last2=Badiola|first2=Ainara|last3=Marigó|first3=Judit|last4=Moyà-Solà|first4=Salvador|year=2013|title=First record of the genus Microchoerus (Omomyidae, Primates) in the western Iberian Peninsula and its palaeobiogeographic implications|journal=Journal of Human Evolution|volume=65|issue=3|pages=313–321|doi=10.1016/j.jhevol.2013.07.002|pmid=23916791 |bibcode=2013JHumE..65..313M }} As part of a separate landmass at the time, La Débruge of France, dating to MP18, yielded slightly different faunas that coexisted with ''A. commune'', ''A. latipes'', and ''A. laurillardi'', namely the herpetotheriid ''Peratherium'', rodents (''[[Blainvillimys]]'', ''Theridomys'', ''[[Plesiarctomys]]'', ''[[Glamys]]''), hyaenodonts (''[[Hyaenodon]]'' and ''[[Pterodon (mammal)|Pterodon]]''), amphicyonid ''[[Cynodictis]]'', palaeotheres (''Plagiolophus'', ''[[Anchilophus]]'', ''Palaeotherium''), dichobunid ''Dichobune'', choeropotamid ''[[Choeropotamus]]'', cebochoerids ''[[Cebochoerus]]'' and ''[[Acotherulum]]'', anoplotheriids ''Dacrytherium'' and ''Diplobune'', tapirulid ''[[Tapirulus]]'', xiphodonts ''Xiphodon'' and ''[[Dichodon (mammal)|Dichodon]]'', cainothere ''[[Oxacron]]'', amphimerycid ''Amphimeryx'', and anthracothere ''[[Elomeryx]]''.{{cite book|last1=Aguilar|first1=Jean-Pierre|last2=Legendre|first2=Serge|last3=Michaux|first3=Jacques|year=1997|title=Actes du Congrès Bio-chroM'97. Mémoires et Travaux de l'EPHE Institut de Montpellier 21|trans-title=Proceedings of the Bio-chroM'97 Congress. Memoirs and Works of the EPHE, Montpellier Institute 21|chapter=Synthèses et tableaux de corrélations|publisher=École Pratique des Hautes Études-Sciences de la Vie et de la Terre, Montpellier|language=french|pages=769–850|url=https://www.researchgate.net/publication/286785439}} == Extinction == [[File:Headon2.jpg|thumb|left|A panorama of the [[Headon Hill Formation]] in the Isle of Wight, from which Anoplotherium material has been collected. The stratigraphy of it and the [[Bouldnor Formation]] led to better understandings of faunal chronologies from the Late Eocene up to the Grande Coupure.]] The Grande Coupure event during the latest Eocene to earliest Oligocene (MP20-MP21) is one of the largest and most abrupt faunal turnovers in the Cenozoic of Western Europe and coincident with [[climate forcing]] events of cooler and more seasonal climates.{{cite journal|last1=Sun|first1=Jimin|last2=Ni|first2=Xijun|last3=Bi|first3=Shundong|last4=Wu|first4=Wenyu|last5=Ye|first5=Jie|last6=Meng|first6=Jin|last7=Windley|first7=Brian F.|year=2014|title=Synchronous turnover of flora, fauna, and climate at the Eocene-Oligocene Boundary in Asia|journal=Scientific Reports|volume=4|number=7463|page=7463 |doi=10.1038/srep07463 |doi-access=free|pmid=25501388 |pmc=4264005 |bibcode=2014NatSR...4.7463S }} The event led to the extinction of 60% of western European mammalian lineages, which were subsequently replaced by Asian immigrants.{{cite journal|last1=Hooker|first1=Jerry J.|last2=Collinson|first2=Margaret E.|last3=Sille|first3=Nicholas P.|year=2004|title=Eocene–Oligocene mammalian faunal turnover in the Hampshire Basin, UK: calibration to the global time scale and the major cooling event|journal=Journal of the Geological Society|volume=161|issue=2|pages=161–172|doi=10.1144/0016-764903-091|bibcode=2004JGSoc.161..161H|s2cid=140576090|url=http://doc.rero.ch/record/13418/files/PAL_E228.pdf|access-date=2023-08-31|archive-date=2023-08-08|archive-url=https://web.archive.org/web/20230808072039/https://doc.rero.ch/record/13418/files/PAL_E228.pdf|url-status=live}}{{cite journal|last1=Legendre|first1=Serge|last2=Mourer-Chauviré|first2=Cécile|last3=Hugueney|first3=Marguerite|last4=Maitre|first4=Elodie|last5=Sigé|first5=Bernard|last6=Escarguel|first6=Gilles|year=2006|title=Dynamique de la diversité des mammifères et des oiseaux paléogènes du Massif Central (Quercy et Limagnes, France)|journal=STRATA|language=french|series=1|volume=13|pages=275–282|url=https://www.researchgate.net/publication/232607296}}{{cite journal|last1=Escarguel|first1=Gilles|last2=Legendre|first2=Serge|last3=Sigé|first3=Bernard|year=2008|title=Unearthing deep-time biodiversity changes: The Palaeogene mammalian metacommunity of the Quercy and Limagne area (Massif Central, France)|journal=Comptes Rendus Geoscience|volume=340|issue=9–10|pages=602–614|doi=10.1016/j.crte.2007.11.005|bibcode=2008CRGeo.340..602E|url=https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.1016/j.crte.2007.11.005/|access-date=2023-09-19|archive-date=2023-10-13|archive-url=https://web.archive.org/web/20231013195727/https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.1016/j.crte.2007.11.005/|url-status=live|url-access=subscription}} The Grande Coupure is often dated directly to the Eocene-Oligocene boundary at 33.9 Ma, although some estimate that the event began slightly later, at 33.6–33.4 mya.{{cite journal|last1=Costa|first1=Elisenda|last2=Garcés|first2=Miguel|last3=Sáez|first3=Alberto|last4=Cabrera|first4=Lluís|last5=López-Blanco|first5=Miguel|year=2011|title=The age of the "Grande Coupure" mammal turnover: New constraints from the Eocene–Oligocene record of the Eastern Ebro Basin (NE Spain)|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=301|issue=1–4|pages=97–107|doi=10.1016/j.palaeo.2011.01.005|bibcode=2011PPP...301...97C |hdl=2445/34510 |hdl-access=free}}{{cite journal|last1=Hutchinson|first1=David K.|last2=Coxall|first2=Helen K.|last3=Lunt|first3=Daniel J.|last4=Steinthorsdottir|first4=Margret|last5=De Boer|first5=Agatha M.|last6=Baatsen|first6=Michiel L.J.|last7=Von der Heydt|first7=Anna S.|last8=Huber|first8=Matthew|last9=Kennedy-Asser|first9=Alan T.|last10=Kunzmann|first10=Lutz|last11=Ladant|first11=Jean-Baptiste|last12=Lear|first12=Caroline|last13=Moraweck|first13=Karolin|last14=Pearson|first14=Paul|last15=Piga|first15=Emanuela|last16=Pound|first16=Matthew J.|last17=Salzmann|first17=Ulrich|last18=Scher|first18=Howie D.|last19=Sijp|first19=Willem P.|last20=Śliwińska|first20=Kasia K|last21=Wilson|first21=Paul A.|last22=Zhang|first22=Zhongshi|year=2021|title=The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons|journal=Climate of the Past|volume=17|issue=1|pages=269–315|doi=10.5194/cp-17-269-2021|bibcode=2021CliPa..17..269H |s2cid=234099337 |doi-access=free |hdl=11250/3135351|hdl-access=free}} The event occurred during or after the [[Eocene-Oligocene extinction event|Eocene-Oligocene transition]], an abrupt shift from a hot [[greenhouse and icehouse Earth|greenhouse world]] that characterised much of the Palaeogene to a coolhouse/icehouse world from the Early Oligocene onwards. The massive drop in temperatures results from the first major expansion of the Antarctic [[ice sheets]] that caused drastic [[pCO2|pCO2]] decreases and an estimated drop of ~{{cvt|70|m}} in sea level.{{cite journal|last1=Toumoulin|first1=Agathe|last2=Tardif|first2=Delphine|last3=Donnadieu|first3=Yannick|last4=Licht|first4=Alexis|last5=Ladant|first5=Jean-Baptiste|last6=Kunzmann|first6=Lutz|last7=Dupont-Nivet|first7=Guillaume|year=2022|title=Evolution of continental temperature seasonality from the Eocene greenhouse to the Oligocene icehouse –a model–data comparison|journal=Climate of the Past|volume=18|issue=2|pages=341–362|doi=10.5194/cp-18-341-2022|bibcode=2022CliPa..18..341T |doi-access=free }} Many palaeontologists agree that glaciation and the resulting drops in sea level allowed for increased migrations between Balkanatolia and western Europe. The [[Turgai Strait]], which once separated much of Europe from Asia, is often proposed as the main European seaway barrier prior to the Grande Coupure, but some researchers challenged this perception recently, arguing that it completely receded already 37 Ma, long before the Eocene-Oligocene transition. In 2022, Alexis Licht et al. suggested that the Grande Coupure could have possibly been synchronous with the Oi-1 glaciation (33.5 Ma), which records a decline in atmospheric [[carbon dioxide|CO2]], boosting the Antarctic glaciation that already started by the Eocene-Oligocene transition.{{cite journal|last1=Boulila|first1=Slah|last2=Dupont-Nivet|first2=Guillaume|last3=Galbrun|first3=Bruno|last4=Bauer|first4=Hugues|last5=Châteauneuf|first5=Jean-Jacques|year=2021|title=Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France)|journal=Climate of the Past|volume=17|issue=6|pages=2343–2360|doi=10.5194/cp-17-2343-2021|bibcode=2021CliPa..17.2343B |s2cid=244097729 |doi-access=free }} The Grande Coupure event also marked a large faunal turnover marking the arrivals of later anthracotheres, [[entelodont]]s, ruminants ([[Gelocidae]], [[Lophiomerycidae]]), [[Rhinocerotoidea|rhinocerotoids]] ([[Rhinocerotidae]], [[Amynodontidae]], [[Eggysodontidae]]), carnivorans (later Amphicyonidae, [[Amphicynodontidae]], [[Nimravidae]], and [[Ursidae]]), eastern Eurasian rodents ([[Eomyidae]], [[Cricetidae]], and [[Castoridae]]), and eulipotyphlans ([[Erinaceidae]]).{{cite journal|last1=Rivals|first1=Florent|last2=Belyaev|first2=Ruslan I.|last3=Basova|first3=Vera B.|last4=Prilepskaya|first4=Natalya E.|year=2023|title=Hogs, hippos or bears? Paleodiet of European Oligocene anthracotheres and entelodonts|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=611|article-number=111363 |doi=10.1016/j.palaeo.2022.111363|bibcode=2023PPP...61111363R |s2cid=254801829 |doi-access=free}}{{cite journal|last=Becker|first=Damien|year=2009|title=Earliest record of rhinocerotoids (Mammalia: Perissodactyla) from Switzerland: systematics and biostratigraphy|journal=[[Swiss Journal of Geosciences]]|volume=102|issue=3 |pages=489–504|doi=10.1007/s00015-009-1330-4|s2cid=67817430 |doi-access=free|bibcode=2009SwJG..102..489B }}{{cite journal|last1=Solé|first1=Floréal|last2=Fischer|first2=Fischer|last3=Denayer|first3=Julien|last4=Speijer|first4=Robert P.|last5=Fournier|first5=Morgane|last6=Le Verger|first6=Kévin|last7=Ladevèze|first7=Sandrine|last8=Folie|first8=Annelise|last9=Smith|first9=Thierry|year=2020|title=The upper Eocene-Oligocene carnivorous mammals from the Quercy Phosphorites (France) housed in Belgian collections|journal=Geologica Belgica|volume=24|issue=1–2|pages=1–16|doi=10.20341/gb.2020.006|s2cid=224860287 |doi-access=free}} The Eocene-Oligocene transition of western Europe, as a result of the global climatic conditions, is marked by a transition from tropical and subtropical forests to more open, temperate or mixed deciduous habitats with adaptations to increased seasonality. While ''Anoplotherium'' did not last long in the earliest Oligocene, there are disagreements as to whether it survived the Grande Coupure or went extinct at the event. While evidence points towards ''Anoplotherium'' being extirpated from areas like France and the United Kingdom by the Grande Coupure (last occurrences MP20), the perception is complicated by the apparent last survival of ''A. commune'' in the MP21 locality of Möhren 19 in southern Germany (the edge of western Europe) along with ''Palaeotherium medium'' and ''Diplobune quercyi'' (slightly younger localities indicate their extinctions and replacements by Grande Coupure immigrants such as the anthracothere ''Anthracotherium'' and the rhinocerotid ''[[Epiaceratherium]]''). Hooker pointed out that localities like Möhren 19 span earlier times where the surviving endemic faunas are accompanied by some Grande Coupure immigrants but otherwise were not yet joined by certain immigrants such as ''Anthracotherium''. Additionally, the surviving endemics of the locality are missing from other areas dating to MP21. Therefore, he argued that certain older MP21 localities with surviving endemic faunas fill the long gap between the youngest pre-Grande Coupure Lower Hamstead Member and the younger post-Grande Coupure Upper Hamstead Member within the Bouldnor Formation. This interpretation, Hooker explained, means that the localities represented very brief moments of survival of endemic faunas during the Grande Coupure, therefore supporting the idea of a major and rapid faunal extinction and immigration event, including the extinction of ''Anoplotherium'' in the event.{{cite book|editor-last1=Whittaker|editor-first1=John E.|editor-last2=Hart|editor-first2=Malcolm B.|last=Hooker|first=Jerry J.|year=2010|title=Micropalaeontology, Sedimentary Environments and Stratigraphy: a Tribute to Dennis Curry (1912–2001)|chapter=The 'Grande Coupure' in the Hampshire Basin, UK: taxonomy and stratigraphy of the mammals on either side of this major Palaeogene faunal turnover|publisher=Geological Society of London|volume=4|pages=147–215|doi=10.1144/TMS004.8|isbn=978-1-86239-622-7 }} The extinctions of a majority of endemic artiodactyls, including ''Anoplotherium'', have been attributed to competition with immigrant faunas, environmental changes from cooling climates, or some combination of the two. Sarah C. Joomun et al. determined that certain faunas may have arrived later and therefore may have not played roles in the extinctions. They concluded that climate change, which led to increased seasonality and changes in plant food availability, led the artiodactyls to become unable to adapt to the major changes and go extinct.{{cite conference|last1=Joomun|first1=Sarah C.|last2=Hooker|first2=Jerry J.|last3=Collinson|first3=Margaret E.|year=2010|title=Climate Change Versus Competition as the Cause of Ungulate Extinction at the Grande Coupure (Early Oligocene, Europe)|conference=International Palaeontological Congress: London 2010|page=221|url=https://doc.rero.ch/record/32180/files/PAL_E3339.pdf|access-date=2023-08-31|archive-date=2020-06-11|archive-url=https://web.archive.org/web/20200611151222/http://doc.rero.ch/record/32180/files/PAL_E3339.pdf|url-status=live}} Weppe made similar arguments towards climate change being the main cause of the Grande Coupure extinction event, arguing that the cooling climates displaced the previously stable subtropical environments of western Europe and caused a collapse in the artiodactyl community, which after their extinctions left empty ecological niches that were passively filled by immigrant faunas. Weppe and colleagues found that the diversity of endemic artiodactyls was positively impacted by the diversity of immigrant artiodactyls, in addition the diversity of the immigrant artiodactyls negatively correlated with the extinction rate of the endemic artiodactyls. This suggests that immigrant artiodactyls did not play a role in their decline and extinction of endemic artiodactyls, during or after the transition.{{cite journal |last1=Weppe |first1=Romain |last2=Condamine |first2=Fabien L. |last3=Guinot |first3=Guillaume |last4=Maugoust |first4=Jacob |last5=Orliac |first5=Maëva J. |year=2023 |title=Drivers of the artiodactyl turnover in insular western Europe at the Eocene–Oligocene Transition |journal=Proceedings of the National Academy of Sciences |volume=120 |issue=52 |bibcode=2023PNAS..12009945W |doi=10.1073/pnas.2309945120 |pmc=10756263 |pmid=38109543 |doi-access=free |article-number=e2309945120}} == Notes == {{Portal|Paleontology}} {{Notelist}} ==References== {{Reflist}} ==External links== {{Commons category-inline}} {{Taxonbar|from1=Q138945|from2=Q122845073|from3=Q124051193|from4=Q124051200|from5=Q124051207}} [[Category:Anoplotheriidae]] [[Category:Fossil taxa described in 1804]] [[Category:Eocene Artiodactyla]] [[Category:Fossils of France]] [[Category:Taxa named by Georges Cuvier]] [[Category:Prehistoric Artiodactyla genera]] [[Category:Eocene mammals of Europe]] [[Category:Oligocene mammals of Europe]]