''Bryceomys'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

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 ...

that lived during the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period (between 100 and 66 million years ago) and thus shared the world with

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s. It was a member of the also extinct order of

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct Order (biology), order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the M ...

. It was within the suborder of

Cimolodonta Cimolodonta is a clade of Multituberculata, multituberculate mammals that lived from the Cretaceous to the Eocene. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal ...

, and a member of the

Paracimexomys group ''Paracimexomys'' is a genus of extinct mammals in the extinct Multituberculata order. ''Paracimexomys'' lived during the Cretaceous period. The few fossils remains come from North America. Some Romanian fossils were also tentatively assigned to ...

. The genus ''Bryceomys'' ("Bryce mouse", after

Bryce Canyon National Park Bryce Canyon National Park () is a national park of the United States located in southwestern Utah. The major feature of the park is Bryce Canyon, which despite its name, is not a canyon, but a collection of giant natural amphitheaters along ...

) was named by Eaton J.G. in 1995.

Species

The species ''Bryceomys fumosus'' (Eaton 1995) is known from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s found in

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

dating to the Turonian (Upper Cretaceous) in the Straight Cliffs Formation of

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, US. They probably weighed about 12g, about half the weight of a house mouse. About a hundred teeth are held at the

Oklahoma Museum of Natural History The Sam Noble Oklahoma Museum of Natural History is the officially designated natural history museum for the State of Oklahoma, located on the campus of the University of Oklahoma. The museum was founded in 1899 by an act of the Oklahoma Territ ...

, including the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

. Species: ''Bryceomys hadrosus'' Eaton J.G. 1995
Place:

Straight Cliffs Formation The Straight Cliffs Formation is a stratigraphic unit in the Kaiparowits Plateau of south central Utah. It is Late Cretaceous (latest Turonian – early Campanian) in age and contains fluvial (river systems), paralic (swamps and lagoons), and m ...

of Utah
Age: Turonian (Upper Cretaceous)
Also in the Oklahoma collection. Suggested bodyweight is around 90 g. Species: ''Bryceomys intermedius'' Eaton JG & Cifelli RL, 2001
Place:

Cedar Mountain Formation The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah, spanning most of the early and mid-Cretaceous. The formation was named for Cedar Mountain (Utah), Cedar Mountain in northern Emery Cou ...

, Utah
Age: Albian (late) - Cenomanian (early) (Upper Cretaceous)

References

* Eaton (1995), "Cenomanian and Turonian (Early Late Cretaceous) multituberculate mammals from southwestern Utah". ''Journal of Vert Paleo'' 15(4), p. 761-784. * Eaton and Cifelli (2001), "Multituberculate mammals from near the Early-Late Cretaceous boundary, Cedar Mountain Formation, Utah". ''Acta Palaeontologica Polonica'' 46(4), p. 453-518 * Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Paleontology'' 44, p. 389-429. {{Taxonbar, from=Q4980732 Cimolodonta Late Cretaceous mammals of North America Fossil taxa described in 1995 Prehistoric mammal genera