Neoliotomus
Scientific classification
Kingdom: Animalia
Therapsida
Class: Mammalia
Order: Multituberculata
Superfamily:Ptilodontoidea
Genus: Neoliotomus
Species
  N. conventus
  N. ultimus

Ref.

Neoliotomus is a North American mammal genus from the Paleocene. It existed in the age immediately following the extinction of the last dinosaurs. This animal was a member of the extinct order of Multituberculata.
For those of a technical inclination, it's within the suborder of Cimolodonta, and a member of the superfamily Ptilodontoidea. Other than that, its affinities are somewhat unclear.

Genus: Neoliotomus Jepsen GL, 1930
'new Liotomus'
Aka: Eucosmodon (partly)

Species: Neoliotomus conventus Jepsen GL, 1930
Place: Wyoming, Fort Union Formation, Montana & Colorado
Country: USA
Age: Clarkforkian, Paleocene
Remarks: A fairly large multituberculate of around 1,9kg. The holotype is in the Peabody Museum, Yale.
Reference: Jepsen (1930), New vertebrate fossils from the Lower Eocene of the Bighorn Basin, Wyoming. Proc. Amer. Philos. Soc. 69, p.117-131, 4 pls.

Species: Neoliotomus ultimus (Granger W & Simpson GG, 1928)
Aka: Eucosmodon ultimus Granger & Simpson, 1928
Place: Wyoming & Colorado
Country: USA
Age: Clarkforkian, Paleocene
Remarks: Known from a fair number of locations. Another large multi, which weighed perhaps 2 kilos.
Reference:

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)