Artiodactyla

Mounted skeleton of Cainotherium at the Natural History Museum, Basel, copyright Ghedoghedo.

Belongs within: Euungulata.
Contains: Choeropotamoidea, Anoplotherioidea, Oreodonta, Camelidae, Suina, Ruminantiamorpha, Cetancodontamorpha.

The Artiodactyla are a clade of mammals containing the even-toed hoofed mammals, as well as the cetaceans which are nested well within this group. Most recent studies place the cetaceans closest to the Hippopotamidae among living artiodactyls, with the two in turn often sister to the Ruminantia. Previously, the ruminants had been thought more closely related to the Camelidae due to shared characters such as stomach divided into three or four chambers and rear teeth with crescent-shaped cusps. However, modern molecular analyses mostly place camelids as the sister group to all other living artiodactyls.

The Artiodactyla have an extensive fossil record going back to the Eocene, but the affinities of many basal taxa are currently uncertain in the light of the aforementioned changes in our understanding of artiodactyl phylogeny. The Cainotheriidae are small, rabbit-sized animals known from the late Eocene to the middle Miocene of Europe that may be distantly related to the camels. The Dichobuninae and Hyperdichoduninae are other groups of small artiodactyls (or possibly stem-artiodactyls) from the Eocene of Europe. The Dichobuninae have a bulbous dentition and moderately elongated snouts. The Hyperdichobuninae have molarised, crescentiform premolars and molars with a tendency to broaden the distal side of the latter.

See also: Where do you put your camels?

Synapomorphies (from Spaulding et al. 2009, for Artiodactylamorpha): Sustentacular facet wide; contact of distal astragalus with cuboid present; ectal facet primary orientation lateral; astragalus with lateral edges of proximal and distal trochlea aligned; astragalar head arc to dorsoplantar wide, ~200 degrees; astragalar neck as wide as tibial trochlea.

Artiodactyla (see below for synonymy) SOG09
    |--Camelidamorpha SOG09
    |    |--Oreodonta SOG09
    |    `--+--+--Camelidae TC07
    |       |  |--Oromerycidae GH88
    |       |  |--Eotylops TC07
    |       |  `--Poebrotherium Leidy 1848 SOG09, D07
    |       |       |--P. labiatum HUG17
    |       |       `--P. wilsoni D07
    |       `--Cainotheriidae GH88
    |            |--Robiacina GH88
    |            `--Cainotherium Bravard 1835 SOG09, D07
    |                 |--C. commune D07
    |                 |--C. geoffroyi D07
    |                 `--C. laticurvatum D07
    `--+--Suina SOG09
       `--Cetruminantia [Cetruminantiamorpha] SOG09
            |--Ruminantiamorpha SOG09
            `--Cetancodontamorpha SOG09

Artiodactyla incertae sedis:
  Heptacodon GH01
  Siamotragulus CJ03
  Merychyus Leidy 1858 C77
    |--M. elegans C77
    |--M. major C77
    `--M. medius Leidy 1858 C77
  Wasatchia GH88
  Chorlakkia GH88
  Lantianius GH88
  Texodon GH88
  Bunomerycidae GH88
    |--Bunomeryx Wortman 1898 TC07, GH88
    |--Hylomeryx Peterson 1919 GH88
    |--Mytonomeryx Gazin 1955 GH88
    `--Pentacemylus Peterson 1931 GH88
  Arretotherium MS56
    |--A. acridens Douglass 1901 MS56
    `--A. fricki Macdonald & Schultz 1956 MS56
  Masritherium Fourtau 1918 B78
    `--*M. depereti Fourtau 1918 B78
  Hyoboops Trouessart 1904 B78
    |--*H. palaeindicus (Lydekker 1883) B78
    |--H. africanus (Andrews 1914) [=Merycops africanus] B78
    `--H. moneyi (Fourtau 1918) [=Brachyodus moneyi] B78
  Anthracothema S68
  Choeropotamoidea BLB05
  Gervachoerus TW01
  Aumelasia Sudre 1980 SL00
  Protodichobune Lemoine 1878 SL00
    `--*P. oweni Lemoine 1878 SL00
  Messelobunodon GH88
  Dichobuninae GH88
    |--Dichobune Cuvier 1822 GH88
    |--Metriotherium Filhol 1882 GH88
    `--Meniscodon Rütimeyer 1888 GH88
         `--M. europaeus (Ruetimeyer 1888) [=Phenacodus europaeus] T90
  Sarcolemur Cope 1875 C77 [incl. Antiacodon Marsh 1872 (n. n.) GH88, C77]
    |--*S. furcatus C77
    |--S. crassus (Cope 1875) [=Antiacodon crassus] C77
    |--S. mentalis (Cope 1875) [=Antiacodon mentalis] C77
    `--S. pygmaeus C77
  Hyperdichobuninae GH88
    |--Hyperdichobune Stehlin 1910 GH88
    `--Mouillacitherium Filhol 1882 GH88
  Brachycrus Merriam 1919 D07
    |--B. buwaldi W69
    |--B. laticeps D07
    `--B. siouense D07
  Protylopus Wortman 1898 D07
    `--P. petersoni D07
  Aepycamelus Leidy 1886 D07
    |--A. alexandrae D07
    |--A. bradyi D07
    |--A. elrodi D07
    |--A. giraffinus D07
    |--A. major D07
    |--A. priscus D07
    |--A. proceras D07
    |--A. robustus D07
    `--A. stocki D07
  Titanotylopus Barbour & Schultz 1934 D07
    |--T. nebraskensis D07
    `--T. spatulus D07
  Leptotragulidae GH88
  Amphimeryx [Amphimerycidae] TC07
  Anoplotherioidea TC07
  Anthracokeryx ulnifer SOG09
  Microbunodon minimum BLB05
  Gobiohyus SOG09
    |--G. orientalis Matthew & Granger 1925 GH88, SL00
    |--G. pressidens HUG17
    `--G. robustus HUG17
  ‘Proviverra’ americanus Scott 1892 V65

Artiodactyla [Ancodonta, Anthracotheriidae, Anthracotherioidea, Bunodontia, Cameloidea, Cetartiodactyla, Dichobunidae, Dichobunoidea, Helohyidae, Merycotheria, Neoselenodontia, Palaeodonta, Selenodontia, Suiformes, Tylopoda, Whippomorpha] SOG09

*Type species of generic name indicated

REFERENCES

[B78] Black, C. C. 1978. Anthracotheriidae. In: Maglio, V. J., & H. B. S. Cooke (eds) Evolution of African Mammals pp. 423–434. Harvard University Press: Cambridge (Massachusetts).

[BLB05] Boisserie, J.-R., F. Lihoreau & M. Brunet. 2005. The position of Hippopotamidae within Cetartiodactyla. Proceedings of the National Academy of Sciences of the USA 102 (5): 1537–1541.

[CJ03] Chaimanee, Y., D. Jolly, M. Benammi, P. Tafforeau, D. Duzer, I. Moussa & J.-J. Jaeger. 2003. A Middle Miocene hominoid from Thailand and orangutan origins. Nature 422: 61–65.

[C77] Cope, E. D. 1877. Report upon the extinct Vertebrata obtained in New Mexico by parties of the expedition of 1874. Geographical Surveys West of the One Hundredth Meridian 4 (2): i–iv, 1–370.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[GH88] Gentry, A. W., & J. J. Hooker. 1988. The phylogeny of the Artiodactyla. In: Benton, M. J. (ed.) The Phylogeny and Classification of the Tetrapods vol. 2. Mammals pp. 235–272. Clarendon Press: Oxford.

[GH01] Gingerich, P. D., M. ul Haq, I. S. Zalmout, I. H. Khan & M. S. Malkani. 2001. Origin of whales from early artiodactyls: hands and feet of Eocene Protocetidae from Pakistan. Science 293: 2239–2242.

[HUG17] Halliday, T. J. D., P. Upchurch & A. Goswami. 2017. Resolving the relationships of Paleocene placental mammals. Biological Reviews 92 (1): 521–550.

[MS56] Macdonald, J. R., & C. B. Schultz. 1956. Arretotherium fricki, a new Miocene anthracothere from Nebraska. Bulletin of the University of Nebraska State Museum 4 (3): 53–67.

[S68] Simons, E. L. 1968. African Oligocene mammals: introduction, history of study, and faunal succession. Peabody Museum of Natural History, Yale University, Bulletin 28: 1–21.

[SOG09] Spaulding, M., M. A. O'Leary & J. Gatesy. 2009. Relationships of Cetacea (Artiodactyla) among mammals: increased taxon sampling alters interpretation of key fossils and character evolution. PLoS One 4 (9): e7062.

[SL00] Sudre, J., & G. Lecomte. 2000. Relations et position systématique du genre Cuisitherium Sudre et al., 1983, le plus dérivé des artiodactyles de l’Éocène inféreur d’Europe. Geodiversitas 22 (3): 415–432.

[T90] Thewissen, J. G. M. 1990. Evolution of Paleocene and Eocene Phenacodontidae (Mammalia, Condylarthra). Museum of Paleontology Papers on Paleontology 29: 1–107.

[TC07] Thewissen, J. G. M., L. N. Cooper, M. T. Clementz, S. Bajpai & B. N. Tiwari. 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature 450: 1190–1194.

[TW01] Thewissen, J. G. M., E. M. Williams, L. J. Roe & S. T. Hussain. 2001. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature 413: 277–281.

[V65] Van Valen, L. 1965. Some European Proviverrini (Mammalia, Deltatheridia). Palaeontology 8 (4): 638–665.

[W69] Woodburne, M. O. 1969. Systematics, biogeography, and evolution of Cynorca and Dyseohyus (Tayassuidae). Bulletin of the American Museum of Natural History 141 (2): 271–356.

Last updated: 31 July 2018.