MESOZOIC CROC EVOLUTION AND BIOGEOGRAPHY:
Insights From the Cretaceous of Madagascar
Dr. Alan Turner
Associate Professor, Department of Anatomical Sciences,
Health Science Center, Stony Brook University
Sunday, April, 23, 2017 2:00 P.M. Room 319
American Museum of Natural History New York City
Crocodyliforms (living crocodylians and their extinct relatives) are an exceptional radiation of archosaur reptiles spanning over 200 million years and multiple mass extinction events. These animals evolved over 4 orders of magnitude in body size and into ecological and phenotypic diversity paralleling those of Cenozoic mammals. The past 10 to 15 years has witnessed an explosion of discoveries of fossil crocodyliforms. The number of known species has more than quadrupled since 2000. Most of these remain unanalyzed. In particular discoveries from Jurassic and Cretaceous rocks are reshaping our understanding of the croc evolutionary tree. The crocodyliform fossil record, and their history of evolutionary change, are critical towards answering key questions regarding when and to what extent the fragmentation of Pangaea influenced biotic change during the Mesozoic.
For over 15 years Dr. Turner’s involvement in the Madagascar Paleontological Project has contributed to the description and understanding of Madagascar’s unparalleled crocodyliform fauna. A joint project between Stony Brook University, Ohio University, Denver Museum of Nature and Science, and Macalester College, the MPP has collected thousands of vertebrae specimens from the Late Cretaceous Maevarano Formation of Madagascar. The crocodyliforms they have found represent 6 distinct species. When compared to modern crocodylian-supporting ecosystems, the co-occurrence of 6 croc species in the Maevarano outstanding. The Madagascar croc fauna is phylogenetically diverse as well as morphological disparate. These species continue to be central to the debate regarding the timing and order of breakup of the Gondwanan landmass in the southern hemisphere during the Jurassic and Cretaceous. Ongoing work suggests the Cretaceous Malagasy croc fauna may be even more important for understanding how the even earlier split between Northern Hemisphere landmasses (Laurasia) and Southern Hemisphere landmasses (Gondwana) structured the evolution of the group.
Note: Our April meeting is on the fourth Sunday of the month to avoid the Easter holiday.
N.Y.P.S. MEETING DATES FOR THE YEAR
These are the meeting dates of the New York Paleontological Society for the 2016-2017 season. We meet at 2:00 P.M. in room 319 at the American Museum of Natural History in New York City (79th Street and Central Park West), unless otherwise specified. Our Annual Party will be held at the NYU Polytechnic School of Engineering in Brooklyn, N.Y. Due to changes in the museum’s schedule, the above dates may change (usually very unlikely), so check your Newsletter or the monthly meeting notice on this website.