Abstract

(…) Phocoena spinipinnis may be distinguished externally from all other members of the genus by the slightly convexed anterior and posterior borders and the rounded blunt tip of the dorsal fin. Horny denticles or spines are present along the anterior border of the dorsal fin.

The skull of P. spinipinnis is similar to that of P. phocoena, but differs by having: (1) the brain case much less compressed from front to back; (2) a dorsal profile of the supraoccipital bone in line with the dorsal profile of the rostrum instead of tilted at an angle of slightly over 20°; (3) a larger temporal fossa; and (4) fewer teeth (13 to 18 in each upper jaw and 15 to 20 in each lower jaw). (…)