Alphadon

{{automatic taxobox

| fossil_range = Late Cretaceous, {{Fossil range|100.5|66}}J. G. Eaton. 1993. Therian mammals from the Cenomanian (Upper Cretaceous) Dakota Formation, southwestern Utah. Journal of Vertebrate Paleontology 13(1):105-124

| image = Alphadon sp. - MUSE.jpg

| image_caption = Reconstruction of Alphadon sp.

| taxon = Alphadon

| authority = Simpson, 1927

| subdivision_ranks = Species

| subdivision_ref = {{Cite web

| last = Haaramo | first = Mikko

| title = Alphadontidae

| publisher = Mikko's Phylogeny Archive |date=August 2003

| url = http://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/synapsida/metatheria/boreometatheria/alphadontidae.html}}

| subdivision =

A. marshi (type)
Simpson, 1927
A. wilsoni
Lillegraven, 1969
A. halleyi
Sahni, 1972
A. attaragos
Lillegraven & McKenna, 1986
A. sahnii
Lillegraven & McKenna, 1986
A. clemensi
Eaton, 1993
A. lillegraveni
Eaton, 1993
A. perexiguus
Cifelli, 1994
A. eatoni
Cifelli & Muizon, 1998

}}

Alphadon is an extinct genus of small, primitive mammal that was a member of the metatherians, 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 {{Convert|12|in|cm|abbr=on}} and may have resembled a modern opossum.{{Cite web | last = Jehle | first = Martin | title = Marsupials: A southern success story | publisher = Paleocene mammals of the world |date=August 2005 | url = http://www.paleocene-mammals.de/marsupials.htm}} 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.{{cite journal |title=Alphadon halleyi (Didelphidae, Marsupialia) from the Two Medicine Formation (Late Cretaceous, Judithian) of Montana |journal=Journal of Vertebrate Paleontology |year=1988 |volume=8 |issue=4 |pages=378–382 |first=Marisol |last=Montellano|doi=10.1080/02724634.1988.10011726 }}

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 herpetotheriid genus Nortedelphys.{{cite journal |author1=Thomas E. Williamson |author2=Stephen L. Brusatte |author3=Thomas D. Carr |author4=Anne Weil |author5=Barbara R. Standhardt |title=The phylogeny and evolution of Cretaceous–Palaeogene metatherians: cladistic analysis and description of new early Palaeocene specimens from the Nacimiento Formation, New Mexico |journal=Journal of Systematic Palaeontology |volume=10 |issue=4 |pages=625–651 |year=2012 |doi=10.1080/14772019.2011.631592 }}

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.{{cite journal | title = A large carnivorous mammal from the Late Cretaceous and the North American origin of marsupials | journal = Nature Communications | volume = 7 | pages = 13734 | date = 2016 | first1 = G.P. | last1 = Wilson | first2 = E.G. | last2 = Ekdale | first3 = J.W. | last3 = Hoganson | first4 = J.J. | last4 = Calede | first5 = A.V.| last5 = Linden | doi = 10.1038/ncomms13734 | pmid = 27929063 | pmc = 5155139 }}

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|label1=Marsupialiformes

|1={{clade

|1=Gurlin Tsav skull

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|1=Borhyaenidae

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|1=Mayulestes

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|1=Jaskhadelphys

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|1=Andinodelphys