A NEW SPECIES OF CORMORANT FROM THE PLIOCENE OF MEXICO HiLDEGARDE HoWARD^ Los Angeles County Museum The occurrence of vertebrate fossils in deposits south of the small town of La Goleta, near Morelia, Michoacan, Mexico, was first dis-cussed by Arellano and Azcon ( 1 949 ) at the El Paso, Texas, meeting of the Geological Society of America. In 1950, the California Insti-tute of Technology (CIT) collected in the La Goleta area, followed, five years later, by the Los Angeles County Museum (LACM). The material collected on both of these expeditions is now in the collec-tions of the latter institution. A brief discussion of the Michoacan beds, based on an unpublished report of the field party from California Institute of Technology is presented by Repenning (1962:554), who records the occurrence of the giant ground squirrel, Paenemarmota, in the Goleta fauna. Ex-cept for Paenemarmota, the only other generic or specific identifica-tions from the fauna have been of horses assigned to Nannipus cf. montezuma and Pliohippus osborni (Arellano and Azcon, 1949). On the basis of the horses, the Goleta fauna has been placed in the Pliocene. A difference of opinion exists, however, as to whether it should be considered of Hemphillian (middle Pliocene) or early Blancan (late Pliocene) age (Repenning, 1962:554-555; and Octo-ber, 1964, correspondence with the present writer from R. H. Ted-ford who takes the latter view) . Undescribed mammalian specimens representing mastodon, hyaenid, peccary, tapir, rabbit, rodent, antelope and camel are in-cluded in the fauna (Repenning, 1962:554-555). Only two avian bones occur, both representing a small cormorant of lesser size than the Recent Phalacrocorax olivaceus, known in the area today. For-tunately an almost complete coracoid is present, an element that is particularly diagnostic in the cormorants. More significant than the size difference from P. olivaceus are physical characters of the cora-coid that serve to distinguish the fossil. The Goleta species is, there-fore, here described as new to science: ^Research Associate. 50
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