Mammal size shows that there was likely no archipelago in southern Central America during the Miocene.

The formation of the Isthmus of Panama during the latest Cenzoic was important event because it facilitated the mixing of terrestrial faunas between North and South America. Not since the late Cretaceous were terrestrial animals able to walk from North America to South America or vise versa. During the middle Cenozoic little is known of the paleogeography of southern Central America. For example did North America extend southward as an island arc system or as a peninsula. To investigate this question Michael Xavier Kirby from the Smithsonian Tropical Research Institute in Panama, and Bruce MacFadden from the University of Florida, measured specimens of mammals from the Gaillard Cut Local Fauna of the Cucaracha Formation in Panama and compared them with specimens of the same species from northern latitudes. They discovered no significant differences and concluded that in fact the Panama Canal Basin, was part of a peninsula rather than a series of islands.


Kirby, Michael Xavier and MacFadden, Bruce (2005) Was southern Central America an archipelago or a peninsula in the middle Miocene? A test using land-mammal body size, Palaeogeography, Palaeoclimatology, Palaeoecology, In Press, Corrected Proof, Available online 6 July 2005.

Basal Monkeys from Egypt

Erik Seiffert, of Oxford University, published in "Science" the discovery of new Anthropoids from the oldest fossil locality (Birket Qarun Locality 2) in the famed Fayum Depression of Egypt. The new specimens adds to the growing record of small noctural basal anthropoids from Asia and Africa. The locality has been correlated to about 37 mya based on magnetostratigraphic evidence. The real socker of the paper is contained in the last paragraph "Finally, our phylogenetic analysis supports the hypothesis that the oldest known crown primate, the African late Paleocene genus Altiatlasius, is a primitive stem anthropoid." This would imply that Anthropoids arose much earlier than previously thought in Africa. It also leans support to the idea that true primates as a group may have arose first during the Paleocene in Africa before becoming widespread during the early Eocene.
(A personal side note: I was fortunte to work with Erik in 2002, when I joined my wife in Egypt. We spent many a happy day in the sand and sun of Birket Qarun Locality 2).

Seiffert, Erik R., Simons, Elwyn L., Clyde, William C., Rossie, James B., Attia, Yousry, Bown, Thomas M., Chatrath, Prithijit, Mathison, Mark E. 2005
Basal Anthropoids from Egypt and the Antiquity of Africa's Higher Primate Radiation
Science 310: 300-304 [DOI: 10.1126/science.1116569]

Returning from the SVP meetings

My summary of the numerous talks and posters I saw in Arizona must await, alas, until I have the time to dwell on the diversity and depth of the research that is going on in the world today......

Bottom-Feeding Plesiosaurs

Gut contents of a plesiosaur lead to the realization that clams (bivalves), snails (gastropods) and hard shelled cephalopods may have been an important component to these long necked aquatic reptiles of the Cretaceous seas. Investigators in Australia have published a description of the stomach contents of two elasmosaurid plesiosaurs found in Queensland, Australia in this week's issue of Science.




McHenry, Colin R., Cook, Alex. G., Wroe, Stephen. 2005 Bottom-Feeding Plesiosaurs Science 310: 75

65th Annual Meeting of the Society of Vertebrate Paleontology

In two weeks I'll be presenting my research at the annual meeting of the Society of Vertebrate Paleontology meetings, hosted by the Mesa Southwest Museum
http://www.mesasouthwestmuseum.com. Since 1997, I've been attending these meetings, and each one is unique. It is a wonderful way for scientists to get together and exchange ideas. This years meeting offers symposiums on fossil fish, early sauropod dinosaurs, mammalian response to climate. One surprise is a unique symposium on evolution and society. Less than half of the U.S. population understands the concept of evolution, which is continually contested by superstition and religious dogma. The focus of the symposium is on education, and will highlight new programs to teach and convey basic scientific information to the public. I will try to update information on specific talks and posters that see when I travel to Mesa, Arizona in two weeks.