THE ENIGMATIC ALVAREZSAURS

Jonah Choiniere
Kalbfleisch Fellow & Gerstner Scholar
Dept. of Paleontology, American Museum of Natural History

Sunday, February 19, 2012, 2:00 P.M. Room 319
American Museum of Natural History New York City

For the last seven years, Jonah Choiniere has been working in China and Mongolia on a group of theropod (meat-eating) dinosaurs known as the Alvarezsauroidea. This group is one of the most recently-described dinosaurian families, but they've been in the American Museum of Natural History (AMNH) paleontology collection since at least 1923 - museum scientists just didn't recognize it until the early 1990's. Pioneering work on alvarezsaur relationships done at the AMNH at that time recognized the significance of the material in the collection and together with newly collected fossils from Mongolia and scrappy remains from South America, researchers described the new group as a basal lineage of flightless birds. At the time, they had ample justification for doing so: alvarezsaurs from Mongolia share numerous features with birds, including a lightly built skull, keeled sternum, fused wrist, and fully retroverted pubis. Their research findings were a media sensation (an alvarezsaur was featured on the cover of Time magazine) and started a scientific controversy about how to define a "bird," and how to recognize early avian relatives. Soon, however, new evidence popped up in the form of fossils from South America suggesting that these features were in fact dramatic examples of convergent evolution, and that alvarezsaurs were more distantly related to birds.

Jonah will talk about new fossil alvarezsaur material (including some fantastic unpublished specimens) from China that addresses this controversy, and he’ll discuss the ongoing work his group is doing at the AMNH on alvarezsaur paleobiology.

N.Y.P.S. MEETING DATES FOR THE YEAR

These are the meeting dates of the New York Paleontological Society for the 2011 2012 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). Our Annual Party will be held at Polytechnic Institute of New York University 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.