Parectypodus

Parectypodus ("beside Ectypodus") is a genus of extinct mammal that lived from the Paleocene to the Eocene of North America. Some of the known fossil material may also be from the Upper Cretaceous. It was named by G.L. Jepsen in 1930.

It was a member of the extinct order of Multituberculata, and it lies within the suborder of Cimolodonta, family Neoplagiaulacidae. The genus has also been known as Mimetodon (partly); Neoplagiaulax (partly); Parectypodus; Perectypodus; and Ptilodus (partly). P. Jepseni is a junior synonym for Stygimys Jepseni.

Species

Species: Parectypodus armstrongi (Johnston PA & Fox RC 1984)
Place: Puercan (Paleocene) of Rav W-1, Saskatchewan, Canada. This specimen resides in the collection of the University of Alberta.

Species: Parectypodus foxi (Storer J.E. 1991). This Maastrichtian (Upper Cretaceous)-age species is estimated to have weighed about 80 g.

Species: Parectypodus laytoni (Jepsen G.L., 1940; Sloan R.E., 1966), also known as Ectypodus laytoni (Jepsen 1940). Remains are known from the Lower Tiffanian (Middle-Upper Paleocene) Princeton Quarry of Wyoming (USA). This species has been cited as a descendant of P. sinclairi. It is a small species, having a weight of perhaps 10 g.

Species: Parectypodus lunatus (Krause DW, 1982), also known as P. childei (Kühne, 1969).
Place: Wasatchian (Lower Eocene) Pocket Quarry of Colorado and Wyoming. This is a late species, having a weight of about 35 g.

Species: Parectypodus sinclairi (Lamb 1902; Clemens 1964a)
Aka: Ectypodus sinclairi (Simpson 1935); Ptilodus sinclairi (Simpson 1935d)
Place: Puercan-Torrejonian (Paleocene) Gidley Quarry of Montana, Wyoming and Alberta, Canada. This species has been cited as having derived from Mesodma formosa. It is a smaller species of about 15 g, which might also go under the name of Liotomus sinclairi.

Species: Parectypodus sloani (Schiebout J.A. 1974)
Aka: Ectypodus sloani. Fossils of this species have been found in the Torrejonian (Paleocene)-age beds of Big Bend, Texas

Species: Parectypodus sylviae (Rigby J.K. 1980; Sloan 1987)
Aka: Ectypodus sylviae (Rigby 1980); ?Ectypodus aphronorus (Sloan 1987); and P. Pattersoni (Sloan 1987). Remains are known from the Torrejonian (Paleocene)-age Swain Quarry of Montana and Wyoming. The body weight of this species has been estimated as 15 g. In 1998, Secord synonymized pattersoni with sylviae.

Species: Parectypodus trovessartianus (Cope E.D. 1882; Van Valen & Sloan 1966)
Aka: Mimetodon trouessartianus Jepsen, 1940; Neoplagiaulax trouessarti; "P. trouessarti"; Ptilodus trouessarti; and Ptilodus trouessartianus (Cope 1882).
Place: Puercan-Torrejonian (Paleocene) San Juan Basin of New Mexico. The body mass of this species has been estimated to have been around 90 g.

References

• Jepsen (1930), "New vertebrate fossils from the lower Eocene of the Bighorn Basin, Wyoming". Proc. Am. Phil. Soc. LXIX, p.117-131.
• Jepsen (1940), "Paleocene faunas of the Polecat Bench formation, Park County, Wyoming". Pro. Amer. Philos. Soc 83, p.217-340, 21 figs., 5 pls.
• Simpson (1935), "New Paleocene mammals from the Fort Union of Montana". Proc. US Nation. Museum 83, p.221-244.
• Schiebout (1974), "Vertebrate paleontology and paleoecology of Paleocene Black Peaks Formation, Big Bend National Park, Texas". Texas Memorial Museum Bull 24: 1-87.
• Johnston and Fox (1984), "Paleocene and Late Cretaceous mammals from Saskatchewan, Canada". Paleontogr. Abt. A: Paläozool., Stratigr 186', p.163-222.
• Kielan-Jaworowska Z. and Hurum J.H. (2001), "Phylogeny and Systematics of multituberculate mammals". Paleontology 44, p.389-429.
• Much of this information has been derived from MESOZOIC MAMMALS; Ptilodontoidea, an Internet directory.