The bone is a right radius of a seal belonging to the family Phocidae and the subfamily Phocinae. It most closely compares with a specimen described as Phoca pontica by Edouard d'Eichwal in 1853. This specimen was found in late Miocene deposits on the Kerch Peninsula, Crimea. Your specimen resembles it in the rather distal position of the pronator and supinator insertions, the great height of the radial crest, and small size. The head, however, appears larger and the biceps insertional area more prominent. Your specimen has a rather prominent outward flexure of the mid shaft which cannot be evaluated in Eichwald's description or illustration.

Other seal radii known (and there are few well-enough preserved to provide comparison) as young as late Pliocene have some similarities not known in living forms. I therefore feel that your specimen is not identifiable to genus and that its age assignment at present can only be suggested as Miocene or Pliocene. It is well preserved and should be identifiable when adequate material for comparison is found. It will be kept and has been assigned No. 23876 in the U.S.N.M. Vertebrate Paleontology Catalog.

Recent studies of the late Miocene species Phoca (Pusa) pontica from Paratethys by Dan Grigorescu of the University of Budapest have greatly strengthened the interpretation of the evolutionary history of the subgenus Pusa. Current analysis of pinniped paleobiogeography by myself, Clayton Ray of the Smithsonian Institution, and Grigorescus have clarified the timing of events leading to the modern distribution of seals, including that of the subgenus Pusa.

The specimen from the Yakataga Formation can now be identified as Phoca (Pusa) cf. of P. (P) siberica, a species now living in Lake Baikal, central Siberia, and very similar to P. (P.) hispida of the Arctic Ocean and P. (P. caspica of the Caspian Sea. The subgenus Pusa evolved from a form introduced into Paratethys from the North Atlantic 13 m.y. ago and evolved in this inland sea. It did not disperse from this area to the Arctic Ocean until about 3 m.y. ago and therefore its entry into the North Pacific can be no older.

In an effort to put an upper limit on the age of the fossil seal samples from 63-APr-261, about 400 feet down section, and from 63-APr-263, about 600 feet up section, were submitted for microfossil examination. Sample 63-APr-263 containing diatoms which John Barron considers late Pliocene, correlating with Schraders 1973 Zones VII to V (Sample MF 3091, Shipment PS-7605M, copy attached). Schrader, 1973, DSDP v. 18, correlates these zones to 1.85 to 2.5 m.y. ago. The lower sample (63-APr-261, MF 3092) contained no diatoms.

Kris McDougall found a good benthic foram fauna in 63-APr-263 and Dick Poore found some planktonic ones in the same samples. 63-APr-162 (MF 3092) contained a poor benthic fauna. No nanno-fossils wer found in either sample. Calls on these faunas are weka and considered only Pliocene/Pleistocene (copy of report attached).

Based largely upon the diatoms, therefore, it would appear that the fossil seal is not as young as Pleistocene and is very late Pliocene, between 3. and 1.8 m.y. old.

The specimen from the Yakataga Formation can now be identified as Phoca (Pusa) cf. of P. (P) siberica, a species now living in Lake Baikal, central Siberia, and very similar to P. (P.) hispida of the Arctic Ocean and P. (P. caspica of the Caspian Sea. The subgenus Pusa evolved from a form introduced into Paratethys from the North Atlantic 13 m.y. ago and evolved in this inland sea. It did not disperse from this area to the Arctic Ocean until about 3 m.y. ago and therefore its entry into the North Pacific can be no older.

Based largely upon the diatoms, therefore, it would appear that the fossil seal is not as young as Pleistocene and is very late Pliocene, between 3. and 1.8 m.y. old.