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 ↓ | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| 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]