Allodesmus, Boessenecker & Churchill, 2018

Allodesmus n. sp. Barnes and Hirota, 1995

Etymology: Allodesmus demerei is named in honor of Dr. Thomas A. Deméré for his mentorship, support, and influential contributions to the study of fossil pinnipeds and other marine mammals.

Diagnosis of species: A large species of Allodesmus similar in adult size to Al. kernensis and Al. sadoensis , and differing from Al. naorai and Al. packardi in possessing a prenarial shelf that is anteriorly transversely expanded, and differing from Al. sinanoensis in lacking tusk-like canines. With the exception of Al. naorai , Al. demerei differs from all Allodesmus in exhibiting proportionally more elongate and triangular nasals that are widest anteriorly. Allodesmus demerei differs from Al. kernensis in exhibiting more strongly developed nuchal crests, which obscure the occipital condyles in dorsal view, a jugal that extends posteriorly to the level of the glenoid fossa, and a proportionally deeper mandible, and from Al. sadoensis in retaining an M 2. Allodesmus demerei further differs from all other Allodesmus in possessing a dorsally prominent and sharply triangular postorbital process, lacking postcanine diastemata, exhibiting a posteriorly elongate neural spine of the axis that overhangs C3, and a transversely expanded and dorsoventrally flattened anterior half of the manubrium.

Holotype: UWBM 75640 About UWBM , a partial articulated skeleton including skull and mandible missing all teeth other than right P 1, hyoid bones, vertebral column (C1– T13 ), ribs, and manubrium. Collected 26–27 September 1984, by P. K. Bigelow and colleagues.

Type locality and stratigraphic context: University of Washington-Burke Museum locality C0343, 140 m above the base of the lower member of the Montesano Formation exposed in bank of Canyon River near Grays Harbor, WA, USA; upper Miocene, 10.5–9.1 Mya in age based on paleomagnetism (Tortonian equivalent; Prothero & Lau, 2001). More detailed locality information is available on request from UWBM to qualified researchers .

Tentatively referred specimen: UWBM 109823, left humerus missing the head, collected by M. S. Kelly from the lower Montesano Formation along the bank of the west fork of the Satsop River near Swinging Bridge Park, Grays Harbor County, WA, USA. More detailed locality information is available on request from UWBM to qualified researchers.

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