Geography of Phocid Evolution

• Published in: Systematic Zoology
• Main Author: Ray, Clayton E.
• Format: Text
• Language: English
• Published: Oxford University Press 1976
• Subjects: Symposium: Advances in Systematics of Marine Mammals; Antarctic; Pacific; Antarc*; North Atlantic
• Online Access: http://sysbio.oxfordjournals.org/cgi/content/short/25/4/391; https://doi.org/10.2307/2412513

Ray, C. E. (Department of Paleobiology, Smithsonian Institution, Washington, D. C. 20560) 1976. Geography of Phocid Evolution. Syst. Zool. 25:391–406 .—Phocid distribution suggests origin in and primary radiation from the North Atlantic-Paratethyan region. Phocines and monachines are equally old groups, known first from the lower middle Miocene Calvert Formation. Phocines dominated Paratethys in semi-isolation. Both groups dispersed freely around the margins of the North Atlantic in Miocene and Pliocene time. Phocines entered the North Pacific, probably from the north, in Pliocene time, and have modernized and radiated in latest Cenozoic time, exclusively in the cold waters of the northern hemisphere. Monachine distribution receded southward in the North Atlantic during latest Cenozoic time, and in the Pliocene they spread into both the southern hemisphere, where they radiated in the empty Antarctic, and into the Pacific via the middle American seaway.