Outline of Eastern North Pacific Fossil Cetacean Assemblages

• Published in: Systematic Zoology
• Main Author: Barnes, Lawrence G.
• Format: Text
• Language: English
• Published: Oxford University Press 1976
• Subjects: Symposium: Advances in Systematics of Marine Mammals; Baja; Pacific; baleen whales; Sperm whale
• Online Access: http://sysbio.oxfordjournals.org/cgi/content/short/25/4/321; https://doi.org/10.2307/2412508

Barnes, Lawrence G. (Section of Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, California 90007) 1976. Outline of eastern North Pacific fossil cetacean assemblages. Syst. Zool. 25:321–343 .—Geologic formations on the west coast of North America from Baja California, Mexico to central California, U.S.A., provide fossil evidence for a succession of Tertiary cetacean assemblages. Formations representing time periods of stage magnitude from early Miocene to Pleistocene age produce diverse aggregates of Cetacea containing fewer species than can now be found in latitudes corresponding to the Californian Province in the Pacific Ocean. Most fossil assemblages include a sperm whale, several dolphin-like taxa, and 3 or 4 baleen whales, although taxonomy is unstable, and many specimens cannot be assigned to named genera and species. New records of the earliest North Pacific occurrence of the families Balaenidae, Ziphiidae, Monodontidae, Phocoenidae, and Delphinidae ( sensu stricto ) date from the Miocene, and of the Eschrichtiidae from the Pleistocene. Squalodontidae are notable by their rarity. Early Miocene assemblages are dominated by Eurhinodelphidae, and late Tertiary ones by Stenodelphininae and primitive Balaenopteridae. On the generic level, there is a high degree of endemism among small Odontoceti, and a low degree among Physeteridae and Mysticeti. Collecting biases and deficiencies prevent recognition of antitropical distributions of fossil taxa, and paleoclimatology can not yet be inferred from the fossils.