''Metacheiromys'' ("next to ''Cheiromys''") is an extinct genus of palaeanodont mammal from the

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

subfamily Metacheiromyinae within paraphyletic family Metacheiromyidae, that lived in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

(what is now

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

) during the early to middle

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

. ''Metacheiromys'' was a small creature, and measured around long. It had long claws and a narrow head similar in shape to that of an

armadillo Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order Cingulata. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, along wi ...

or an

anteater Anteater is a common name for the four extant mammal species of the suborder Vermilingua (meaning "worm tongue") commonly known for eating ants and termites. The individual species have other names in English and other languages. Together with ...

(though it was actually related to the modern

pangolin Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (, from Ancient Greek ϕολιδωτός – "clad in scales"). The one extant family, the Manidae, has three genera: '' Manis'', '' Phataginus'', and '' Smut ...

s). 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. The generic name means "next to ''Cheiromys''" because the scientist who saw the bones mistakenly thought that the animal was a

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...

with hands like those of the

aye-aye The aye-aye (''Daubentonia madagascariensis'') is a long-fingered lemur, a strepsirrhine primate native to Madagascar with rodent-like teeth that perpetually grow and a special thin middle finger. It is the world's largest nocturnal primate. ...

(''Daubentonia madagascariensis''), one synonym being ''Cheiromys''. ''Metacheiromys'' and its relatives, including the enigmatic ''

Ernanodon ''Ernanodon antelios'' ("a growing sprouts of toothless animals") is an extinct placental mammal from the middle Paleocene Nongshan Formation of China. It was a relatively small animal about in length, not including the tail. When it was firs ...

'', constitute the order

Palaeanodonta Palaeanodonta ("ancient toothless animals") is an extinct clade of stem- pangolins. They were insectivorous, possibly fossorial, and lived from the Early Paleocene to Early Oligocene in North America, Europe and East Asia. While the taxonomic ...

, thought to be the sister taxon of

Phylogenetic tree

The phylogenetic relationships of genus ''Metacheiromys'' is shown in the following cladogram:

References

Palaeanodonta Eocene mammals Eocene mammals of North America {{paleo-mammal-stub