Platyphoca Van Beneden, 1877

Koretsky, I., Rahmat, S. & Peters, N., 2014, Rare Late Miocene Seal Taxa (Carnivora, Phocidae) From The North Sea Basin, Vestnik Zoologii 48 (5), pp. 419-432 : 426-427

Genus Platyphoca Van Beneden, 1877

1876 a Platyphoca Van Beneden : 798 (nom. nud.); *1877 Platyphoca Van Beneden : 67–68; 1904 Phoca (Platyphoca) Trouessart : 285; 1909 Platyphoca Dollo : 118; 1922 Platyphoca Kellogg : 117; 1945 Platyphoca Simpson : 122; 1947 Phoca (Platyphoca) Friant : 7, 10, 14; 1958 Platyphoca Misonne : 22; 1964 Platyphoca King : 131; 1977 Platyphoca Ray : 94; 1983 Platyphoca Savage, Russell : 294; 1992 Platyphoca Muizon : 36; 1997 Platyphoca McKenna, Bell : 258; 2008 Platyphoca Koretsky, Ray : 84–85, 103–105.

T y p e s p e c i e s: Platyphoca vulgaris Van Beneden, 1877 , by original monotypy. Holotype from middle (?) Pliocene (Scaldisian) deposits in the Antwerp area , Belgium.

S t r a t i g r a p h i c a l r a n g e. The type species is also known from the Pliocene (5.0– 5.8 ma) Yorktown Formation of the eastern United States. Herein, we introduce a new species from the late Miocene (early-middle Tortonian, 8.0–11.5 ma) Gram Formation of Gram and Skaerum MØlle, Jutland, western Denmark.

R e f e r r e d m a t e r i a l. Humeri, 2nd phalanx, innominata, metatarsal IV, tibia, and humeri from the Antwerp area, Belgium, from western Denmark, and from the eastern United States (see Koretsky, Ray, 2008).

E m e n d e d d i a g n o s i s. Deltoid crest of humerus very short and terminating at less than 1/2 of length of bone; from base of lesser tubercle, along medial surface of bone, passes a crest that is only slightly shorter than deltoid crest; maximal enlargement of deltoid crest in its proximal part; intertubercular groove very shallow and not well defined; both epicondyles well developed and very wide; distal part of each epicondyle flat.

D i s c u s s i o n. Platyphoca vulgaris (pl. 3, 1A–1B) was originally mentioned by Van Beneden (1876 a), who considered it to be very close to the Recent Erignathus barbatus . The size of the humerus approaches that of Erignathus more closely than any other phocid. This poorly known, obscure, but distinctive species was described on the basis of only a few bones of the postcranial skeleton. P. vulgaris was a very large animal, perhaps similar in size to the modern species Cystophora cristata . This intriguing species has been virtually ignored in the literature except for a few comprehensive works, where Platyphoca vulgaris is listed among species from the Pliocene of Europe (e. g. Trouessart, 1904; Kellogg, 1922; Simpson, 1945; King, 1964; Muizon, 1992).