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.[
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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.
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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.