Paracimexomys
Encyclopedia
Paracimexomys is a genus
of extinct mammal
s in the also extinct Multituberculata
order. Paracimexomys lived during the Cretaceous
period. The few fossils remains come from North America
. Some Romania
n fossil
s were also tentatively assigned to this genus
, though that classification now seems doubtful.
The genus Paracimexomys ("beside Cimexomys
") was named by Archibald J.D. in 1982. It is also known as Cimexomys sp. (Sloan & Van Valen, 1965). Paracimexomys fossil
s were originally referred as Cimexomys, until it was realized they were different enough to justify a genus of their own.
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...
s in the also extinct 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...
order. Paracimexomys lived during the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period. The few fossils remains come from 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...
. Some Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
n fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s were also tentatively assigned to this genus
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...
, though that classification now seems doubtful.
The genus Paracimexomys ("beside Cimexomys
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 the suborder Cimolodonta...
") was named by Archibald J.D. in 1982. It is also known as Cimexomys sp. (Sloan & Van Valen, 1965). Paracimexomys fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s were originally referred as Cimexomys, until it was realized they were different enough to justify a genus of their own.
Species
- ?Paracimexomys crossi- Remains have been found in the Upper Aptian-Albian (Lower CretaceousCretaceousThe Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
) strataStratumIn geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
of the Antlers Formation in OklahomaOklahomaOklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
, 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 magister also known as Cimexomys magister- Remains were found in the Upper SantonianSantonianThe 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 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...
(Upper Cretaceous) of UtahUtahUtah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, USA. The animal probably weighed about 100g when it was alive. - Paracimexomys magnus also known as Cimexomys magnus- Found in the CampanianCampanianThe Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
(Upper Cretaceous) strata of the Judith River Formation in MontanaMontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, USA. - Paracimexomys perplexus- Found in the late AlbianAlbianThe 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 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
to early CenomanianCenomanianThe Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
(Upper Cretaceous) in the Cedar Mountain Formation of Utah. - Paracimexomys priscus also known as Cimexomys priscus- Fossil remains were found in the MaastrichtianMaastrichtianThe Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
(Upper Cretaceous) of Hell Creek, Montana. Remains were first found in 1966. The holotype is in the collection of the University of AlbertaUniversity of AlbertaThe University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...
, where the name Cimexomys is favoured. Weight is estimated to have been 60g. - Paracimexomys robisoni Found in the Upper Cretaceous strata of the Cedar Mountain Formation of Utah. Theis type of fossil can be found in the Oklahoma Museum of Natural History. This mouse-sized animal weighed about 25g.
- ?Paracimexomys bestia seems to have possibly become CedaromysCedaromysCedaromys 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 possible member of the Paracimexomys group.The genus Cedaromys was named by...
bestia.