''Filikomys'' is an extinct
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
from the
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...
of
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
. A
multituberculate
Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...
, it demonstrates complex social behaviours were present in these early mammals.
[Weaver, Lucas N.; Varricchio, David J.; Sargis, Eric J.; Chen, Meng; Freimuth, William J.; Wilson Mantilla, Gregory P. (2 November 2020). "Early mammalian social behaviour revealed by multituberculates from a dinosaur nesting site". Nature Ecology & Evolution. 5 (1): 32–37. doi:10.1038/s41559-020-01325-8. PMID 33139921. S2CID 226241443.] The
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
is ''F. primaevus''; a second, smaller species, ''F. minor'', has been tentatively assigned to the genus.
Description
''Filikomys primaevus'' is a roughly squirrel sized mammal. Several individuals were found within the same locale. The holotype is a dentary, NMC 1890.
Etymology
From Greek ''Filikós'' "friendly", and ''mys'', mouse, alluding to its social behaviour. ''Primaevus'' is Latin for youthful.
Classification
''Filikomys primaevus'' is nested among the
Ptilodontoidea
Ptilodontoidea is a group of extinct mammals from the Northern Hemisphere.
They were generally small, somewhat rodent-like creatures of the extinct order Multituberculata.
Some of these genera have a great many species, though remains are gene ...
.
Social behaviour
Several individuals were found co-habitating a burrow. This suggests multituberculates had complex social behaviours like modern mammals,
which in particular have been compared to the social complexity of
placentals.
References
{{Taxonbar, from=Q101095832
Cretaceous mammals
Extinct mammals of North America
Prehistoric mammal genera