Metacheiromys

Metacheiromys ("next to Cheiromys") is an extinct genus of placental mammals from extinct paraphyletic subfamily Metacheiromyinae within extinct paraphyletic family Metacheiromyidae in extinct order Palaeanodonta, that lived in North America (what is now Wyoming) from the early to middle Eocene.

Metacheiromys Temporal range: 50.0–46.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ early to middle Eocene
Skeleton of Metacheiromys marshi
Reconstruction of Metacheiromys marshi
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Palaeanodonta
Family:	†Metacheiromyidae
Subfamily:	†Metacheiromyinae
Genus:	†Metacheiromys Wortman, 1903
Type species
†Metacheiromys marshi Wortman, 1903
Species
†M. dasypus (Osborn, 1904)[1] †M. marshi (Wortman, 1903)[2]
Synonyms
synonyms of species: M. dasypus: Metacheiromys osborni (Simpson, 1931)[3] M. marshi: Metacheiromys tatusia (Osborn, 1904)

Etymology

The generic name means "next to Cheiromys" because the scientist who saw the bones mistakenly thought that the animal was a primate with hands like those of the lemurs from genus Daubentonia, whose synonym is Cheiromys.

Characteristics of taxa

Metacheiromys was a small creature, and measured around 45 centimetres (18 in) long. It had long claws and a narrow head similar in shape to that of an armadillo or an anteater (though it was actually related to the modern pangolins). The shape of its claws suggests that it probably dug through the soil in search of food, most likely small invertebrates. Unlike modern anteaters or pangolins, it had powerful canine teeth, but only a very few cheek teeth, instead using horny pads in its mouth to crush its food.^[4]

Metacheiromys and its relatives, including the enigmatic Ernanodon, constitute the order Palaeanodonta, thought to be the sister taxon of pangolins.^[5]

Phylogenetic tree

The phylogenetic relationships of genus Metacheiromys is shown in the following cladogram:^[6][7][5]

Ferae	Pan-Carnivora Pholidotamorpha Pholidota (sensu stricto) †Palaeanodonta †Escavadodontidae ? †Melaniella †Amelotabes †Epoicotheriidae †Epoicotherium †Molaetherium †Xenocranium †Epoicotheriinae †Tetrapassalus †Dipassalus †Alocodontulum †Auroratherium †Pentapassalus †Tubulodon ? †Arcticanodon †Propalaeanodontinae †Mylanodon †Brachianodon †Palaeanodon †Metacheiromyinae †Metacheiromys †Metacheiromys dasypus †Metacheiromys marshi †Ernanodontidae (Pholidota sensu lato)	†Epoicotherium/Xenocranium clade †Metacheiromyidae

See also

• Paleontology portal

• Mammal classification
• Metacheiromyinae