''Acidomomys'' is a

plesiadapiform Plesiadapiformes (" Adapid-like" or "near Adapiformes") is a group of Primates, a sister of the Dermoptera. While none of the groups normally directly assigned to this group survived, the group appears actually not to be literally extinct (in ...

mammal, meaning that is it a precursor to the

primates 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 ...

or very closely related to them. It belongs to the family

Paromomyidae Paromomyidae is a family of mammals that may include the earliest primates Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which in ...

. ''Acidomomys hebeticus'' fossils were described from the late Paleocene,

Clarkforkian The Clarkforkian North American Stage, on the geologic timescale, is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 56,800,000 to 55,400,000 years BP lasting . Considered t ...

freshwater limestones of Clarks Fork Basin, Wyoming. They appear to have an unusual dental eruption sequence, differing from ''

Plesiadapis ''Plesiadapis'' is one of the oldest known primate-like mammal genera which existed about 58–55 million years ago in North America and Europe. ''Plesiadapis'' means "near-Adapis", which is a reference to the adapiform primate of the Eocene pe ...

'' and other primitive primates and possibly indicating differences in facial appearance or life history.

References

Plesiadapiformes Prehistoric placental genera {{paleo-mammal-stub