Eucosmodon
Encyclopedia
Eucosmodon is a genus
of extinct mammal
from the Paleocene
of North America
. It is a member of the extinct order of Multituberculata
within the suborder of Cimolodonta
, and the family Eucosmodontidae
. This genus has partly also been known as Neoplagiaulax
. All known fossil
s of this small mammal are restricted to teeth.
of New Mexico
(USA).
Eucosmodon americanus is a species of which Puercan
(Paleocene)-age fossils have been found. Some, but not all, of this fossil material has been reclassified as E. primus. This animal, which probably weighed something like 750 g, has been cited as a possible descendant of that species.
Eucosmodon molestus is a species of Torrejonian
(Paleocene) age. It has been cited as a possible descendant of E. americanus.
Eucosmodon primus, also from the Puercan part of the Paleocene, have been found in the Nacimiento Formation
of the San Juan Basin. This species is based on fossils originally ascribed to E. americanus.
A possible fourth species, Eucosmodon kuszmauli, has also been named.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of extinct mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
from the Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. It is a member of the extinct order of Multituberculata
Multituberculata
The Multituberculata were a group of rodent-like mammals that existed for approximately one hundred and twenty million years—the longest fossil history of any mammal lineage—but were eventually outcompeted by rodents, becoming extinct during the early Oligocene. At least 200 species are...
within the suborder of Cimolodonta
Cimolodonta
The Cimolodonta are a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents...
, and the family Eucosmodontidae
Eucosmodontidae
Eucosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from strata dating from the Upper Cretaceous through the Lower Eocene of North America, as well as the Paleocene to Eocene of Europe. The family is part of the...
. This genus has partly also been known as Neoplagiaulax
Neoplagiaulax
Neoplagiaulax is a mammal genus from the Paleocene of Europe and North America. In the case of the latter continent, there may possibly be some slightly earlier, Upper Cretaceous material too. It existed in the age immediately following the extinction of the last dinosaurs...
. All known fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of this small mammal are restricted to teeth.
Species of Eucosmodon
All known species of Eucosmodon have been found in the San Juan BasinSan Juan Basin
The San Juan Basin is a geologic structural basin in the Four Corners region of the Southwestern United States; its main portion covers around , encompassing much of northwestern New Mexico, southwest Colorado, and parts of Arizona and Utah....
of New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
(USA).
Eucosmodon americanus is a species of which Puercan
Puercan
The Puercan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 65,000,000 to 63,300,000 years BP lasting . It is usually considered to be within the Paleocene...
(Paleocene)-age fossils have been found. Some, but not all, of this fossil material has been reclassified as E. primus. This animal, which probably weighed something like 750 g, has been cited as a possible descendant of that species.
Eucosmodon molestus is a species of Torrejonian
Torrejonian
The Torrejonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 63,300,000 to 60,200,000 years BP lasting . It is usually considered to overlap the Selandian and Thanetian within the...
(Paleocene) age. It has been cited as a possible descendant of E. americanus.
Eucosmodon primus, also from the Puercan part of the Paleocene, have been found in the Nacimiento Formation
Nacimiento Formation
The Nacimiento Formation is a sedimentary rock formation found in the San Juan Basin of western New Mexico and named for the Nacimiento Mountains...
of the San Juan Basin. This species is based on fossils originally ascribed to E. americanus.
A possible fourth species, Eucosmodon kuszmauli, has also been named.