Alphadon is an extinct genus of small, primitive mammal that was a member of the , a group of mammals that includes modern-day marsupials. Its fossils were first discovered and named by George Gaylord Simpson in 1929.
Description
Not much is known about the appearance of
Alphadon, as it is only known from teeth, a lower jaw and skull fragments. It probably grew to about and may have resembled a modern
opossum.
Judging from its teeth, it was likely an
omnivore, feeding on fruits, invertebrates and possibly small vertebrates.
Alphadon had a very good sense of smell and sight to track down its food, both during the day and night. Its possible whiskers could have also aided in its search for food.
Taxonomy and classification
The type species is
Alphadon marshi. Eight other species are known.
The species
Alphadon jasoni was originally described by Storer (1991);
[Storer, J.E. (1991). The mammals of the Gryde local fauna, Frenchman Formation (Maastrichtian: Lancian), Saskatchewan. Journal of Vertebrate Paleontology, vol. 11, no. 3, p. 350-396.] it was subsequently transferred to the
Herpetotheriidae genus
Nortedelphys.
Recent phylogenetic studies group it with other northern non-marsupial metatherians such as Albertatherium and Turgidodon.[Guillermo W. Rougier; Brian M. Davis; Michael J. Novacek (2015). "A deltatheroidan mammal from the Upper Cretaceous Baynshiree Formation, eastern Mongolia". Cretaceous Research. 52, Part A: 167–177. doi:10.1016/j.cretres.2014.09.009.][S. Bi, X. Jin, S. Li and T. Du. 2015. A new Cretaceous metatherian mammal from Henan, China. PeerJ 3:e896] A 2016 phylogenetic analysis is shown below.
