Prionessus

Prionessus is a genus of extinct mammal from the Paleocene of what is now Central Asia. It was a member of the extinct order Multituberculata within the suborder Cimolodonta and superfamily Taeniolabidoidea. The genus was named by William Diller Matthew and Walter Granger in 1925, and is based on a single species P.lucifer.^[1]

Prionessus Temporal range: Thanetian ~59–55 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Multituberculata
Family:	†Lambdopsalidae
Genus:	†Prionessus
Species:	†P. lucifer
Binomial name
†Prionessus lucifer W.D. Matthew and W. Granger, 1925

Kielan-Jarowoska and Hurum believe that members of the Taeniolabidoidea, such as Prionessus, are all quite similar. For example, they all share a short wide snout and a blocky head^[2] so it is probably instructive to look at a close and more commonly occurring relative, Lambdopsalis bulla, a likely burrower.^[3][4] Matthew and Granger noted in their discovery that P.lucifer had a robust lower incisor, supportive of this similarity.^[5]

Fossil remains have been found in the Late Paleocene Nomogen and Khashat Formations of Gashato, Naran and Nomogen in Bayan Ulan of Mongolia and China. Prionessus fossils range from 59-55 million years ago, through the Thanetian age of the late Paleocene. They were estimated to have had a body mass of about 370 grams (13 oz).^[6]