Stygimys

Taxobox
name = "Stygimys"
fossil_range = Late Cretaceous - Paleocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Multituberculata
familia = Eucosmodontidae
genus = "Stygimys"
subdivision_ranks = Species
subdivision =
* "S. camptorhiza"
* "S. cupressus"
* "S. jepseni"
* "S. kuszmauli"
* "S. teilhardi"

"Stygimys" is an extinct mammal genus from the Upper Cretaceous and Paleocene of North America. It was a member of the extinct order Multituberculata within the suborder Cimolodonta, family Eucosmodontidae.

The genus "Stygimys" ("Styx mouse") was named by Sloan R.E. and Van Valen L. in 1965. The name comes from the Styx (river of hell) from Greek mythology. The genus has also been known as "Catopsalis" (partly); "Cimexomys" (partly); "Eucosmodon" (partly); and "Parectypodus" (partly). Some skull material is known, but not much.

pecies

The species "Stygimys camptorhiza" was named by Johnston P.A. and Fox R.C. in 1984.Place: Puercan (Paleocene)-age strata of Rav W-1 in Saskatchewan, Canada. The holotype for this species is in the University of Alberta collection.

The species "Stygimys cupressus" was named by Fox R.C. in 1989. Remains are known from the Puercan (Paleocene)-age strata of the Long Fall Horizon of Canada.

The species "Stygimys jepseni" was named by Simpson G.G. in 1935 and Sloan and Van Valen in 1965. It is also known as "Eucosmodon sparsus" (Simpson 1937a); "E. jepseni"; and "Parectypodus jepseni" (Simpson 1935d). Remains are known from the Torrejonian (Paleocene)-age strata of Montana (USA). This species has been cited as a descendant of "S. kuszmauli". The animal weighed about 90 g.

The species "Stygimys kuszmauli" was named by Sloan R.E. and Van Valen L. in 1965. It has also been known as "Catopsalis foliates" (Cope 1882); "Cimexomys gratus" (Jepsen GL, 1930); "Eucosmodon gratus" (Jepson G.L. 1930); "Eucosmodon kuszmauli "; and "Stygimys gratus". Remains were found in Maastrichtian (Upper Cretaceous) - Puercan (Paleocene)-age strata of the Polecat Bench Formation of Wyoming and the Hell Creek Formation of Montana. Some scraps of jaw are known. This species is the most basal member of the genus, with a weight of 300 g.

The species "Stygimys teilhardi" was named by Granger W. & Simpson G.G. in 1929 and Sloan R.E. and Van Valen in 1965. It has also been known as "Eucosmodon teilhardi" (Granger W. & Simpson G.G. 1929). Remains are known from the Torrejonian (Paleocene)-age strata of the San Juan Basin of New Mexico. This species has been cited as a possible descendant of "S. kuszmauli".

References

* Johnston & Fox (1984), "Paleocene and Late Cretaceous mammals from Saskatchewan, Canada". Palaeontogr. Abt. A: Paläozool., Stratigr. 186, p.163-222.
* Sloan & Van Valen (1965), "Cretaceous mammals from Montana". "Science" 148(3367), p.220-227.
* Jepson (1930), "Stratigraphy and paleontology of the Paleocene of northeastern Park County, Wyoming". "Proc. Am. Phil. Soc." 69(7), p.463-528.
* Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". "Paleontology" 44, p.389-429.
* Fox (1989), "The Wounded Knee local fauna and mammalian evolution near the Cretaceous-Tertiary boundary, Saskatchewan, Canada". Palaeontogr. Abt. A: Paläozool., Stratigr. 208, p.11-59 + 6 plates.
* Much of this information has been derived from [http://home.arcor.de/ktdykes/taenio.htm] MESOZOIC MAMMALS: Eucosmodontidae, Microcosmodontidae and Taeniolabidoidea, an Internet directory.