New study of fossil caimans in North America determines their evolutionary history

A new study of two approximately 52-million-year-old fossil finds from the Green River Formation in Wyoming, U.S., has fit them into the evolutionary history of crocodiles. Biogeologists Jules Walter, Dr. Márton Rabi of the University of Tübingen, working with some other colleagues, determined the extinct species Tsoabichi greenriverensis to be an early caiman crocodile. Species of caimans living today do not occur in North America. Their family tree reflects their history of migrations and dispersals. The study has been published in the latest edition of Historical Biology.