Prochetodon
Scientific classification

Kingdom: Animalia
Therapsida
Class: Mammalia
Order: Multituberculata
Superfamily: Ptilodontoidea
Family: Ptilodontidae
Genus: Prochetodon
Species
  P. cavus
  P. foxi
  P. taxus

Ref.

Prochetodon is a mammal genus from the Upper Paleocene to the Lower Eocene of North America. It was a member of the extinct order of Multituberculata.
For those of a technical inclination, it's within the Suborder of Cimolodonta, family Ptilodontidae.

Genus: Prochetodon Jepsen GL, 1940

Species: Prochetodon cavus Jepsen GL, 1940
Place: Princeton Quarry, Wyoming
Country: USA
Age: Upper Paleocene - Lower Eocene
Remarks: The critter weighed about 135g. Material is in the collection of the Peabody Museum, Yale.
Reference: Jepsen (1940), Paleocene faunas of the Polecat Bench formation, Park County, Wyoming. Pro. Amer. Philos. Soc, 83, p.217-340, 21 figs., 5pls.

Species: Prochetodon foxi Krause DW, 1987
Place: Long Draw Quarry, Wyoming & Montana & Swan Hills, Alberta
Country: USA & Canada
Age: Upper Paleocene
Remarks: The body mass was around 200g.
Reference: Krause (1987), Systematic revision of the genus Prochetodon (Ptilodontidae, Multituberculata) from the late Paleocene and early Eocene of western North America. Mich., Univ., Mus. Paleontol., Contrib. 27 (8), p.221-236.

Species: Prochetodon taxus Krause DW, 1987
Place: Clark’s Fork Basin, Wyoming
Country: USA
Age: Clarkforkian, Upper Paleocene
Remarks: This was first tentatively referred to P. cf. carvus, (Krause, 1980). Weight of about 190g.
Reference: Krause (1987), Systematic revision of the genus Prochetodon (Ptilodontidae, Multituberculata) from the late Paleocene and early Eocene of western North America. Mich., Univ., Mus. Paleontol., Contrib. 27 (8), p.221-236.

Page references: Kielan-Jaworowska Z & Hurum JH (2001), Phylogeny and Systematics of multituberculate mammals. Paleontology 44, p.389-429.

(This information has been derived from [1] MESOZOIC MAMMALS; Ptilodontoidea, an internet directory. As that's my webpage, there are no issues of copyright. Trevor Dykes)