Research Interests

Jay O'Sullivan specializes in the study of evolution and ecology of mammals, particularly horses, primates and opossums. He has a doctoral degree in vertebrate paleontology and a master's in biological anthropology.

Questions That Your Field of Study Helps Address

O’Sullivan uses the extensive horse fossil record to test hypotheses addressing biological diversification during adaptive radiations. With it, he has:

• Described a new species of the dwarf horse Archaeohippus;
• Used life table analysis to discover evidence of combat induced mortality in males of the species A. blackbergi;
• Extracted and analyzed stable isotopes of carbon and oxygen to evaluate evolutionary heterochrony and body size reduction in the genus;
• Performed a cladistic analysis and used it to map locomotor adaptations in mid-Cenozoic equids.

Research Project Ideas for Undergraduates

O’Sullivan is very interested in developing a method for digitizing dental and pedal morphology in fossil horses in an attempt to better understand the very fine gradations of morphological change in Oligocene and Miocene taxa. He would also like to devise a way to depict this data graphically.

Recent Publications and/or Presentations

O’Sullivan, Jay A. 2005. Population dynamics of Archaeohippus blackbergi (Mammalia, Equidae) from the Miocene Thomas Farm fossil site of Florida. Bulletin of the Florida Museum of Natural History 45(4)455-470.

O’Sullivan, Jay A. (2008) Evolution of the proximal third phalanx in Oligocene-Miocene equids, and the utility of phalangeal indices in phylogeny reconstruction IN Sargis, EJ, and Dagosto, M, eds. Mammalian Evolutionary Morphology, Kluwer Academic Publishers: Dordrecht, The Netherlands.

Presentation 9/22/2006 – Archaeohippus mannulus, a dwarf three-toed horse from the Oligocene/Miocene of North America. Seminar sponsored by Beta Beta Beta and EPC, University of Tampa.