''Paracimexomys'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of extinct mammals in the also extinct

Multituberculata 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, ...

order. ''Paracimexomys'' lived during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period. The few fossils remains come from North America. Some

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, a ...

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 preserved ...

s were also tentatively assigned to this

, though that classification now seems doubtful. The genus ''Paracimexomys'' ("beside ''

Cimexomys ''Cimexomys'' is an extinct North American mammal that lived from the Upper Cretaceous to the Paleocene. For a while, it shared the world with dinosaurs, but outlived them. It was a member of the extinct order Multituberculata and lies within t ...

''") was named by Archibald J.D. in 1982. ''Paracimexomys''

s were originally referred as ''Cimexomys'', until it was realized they were different enough to justify a genus of their own.

Species

* ''Paracimexomys magister'' also known as ''Cimexomys magister''- Remains were found in the Upper

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. ...

(Upper Cretaceous) of

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

, USA. The animal probably weighed about 100g when it was alive. * ''Paracimexomys magnus'' also known as ''Cimexomys magnus''- Found in 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. Campani ...

(Upper Cretaceous) strata of the Judith River Formation in

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

, USA. * ''Paracimexomys priscus''- Fossil remains were found in the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

(Upper Cretaceous) of Hell Creek, Montana. Remains were first found in 1966. The holotype is in the collection of the

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexander Cameron Ruth ...

, where the name ''Cimexomys'' is favoured. Weight is estimated to have been 60g.

Misassigned species

* ''Paracimexomys crossi''- Remains have been found in the Middle Cretaceous (Upper

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ag ...

to lower

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± ...

)

Antlers Formation The Antlers Formation is a stratum which ranges from Arkansas through southern Oklahoma into northeastern Texas. The stratum is thick consisting of silty to sandy mudstone and fine to coarse grained sandstone that is poorly to moderately sorted ...

of Oklahoma, USA. Based on a tiny tooth, this was the first reported Oklahoma Mesozoic mammal. It's also the oldest known member of the informal Paracimexomys group. The species name honours the prison officer Bobby Cross, who has found this and other fossils. * ''Paracimexomys perplexus''- Found in the late

to early Cenomanian (Upper Cretaceous) in the Cedar Mountain Formation of Utah. * ''Paracimexomys robisoni''- Found in the Middle Cretaceous strata of the Cedar Mountain Formation of Utah. This type of fossil can be found in the Oklahoma Museum of Natural History. This mouse-sized animal weighed about 25g. * ''Paracimexomys bestia'' is now the type species of ''

Cedaromys ''Cedaromys'' ("Cedar mouse") is an extinct mammal which lived during the Upper Cretaceous, at the same time as many dinosaurs. It was a member of the also extinct order of Multituberculata. It's within the suborder of Cimolodonta, and a possibl ...

''.

Species

Misassigned species

References

Further reading