Cycling, macintosh, natural history and life in Singapore - Archives
Fri 26 May 2006
Symposium Dinosaurs! Day 2
Category : museum
Day 2: 26 May 2006 (Friday)
2:00 PM Registration (just sign in)
2:30 PM Peter Makovicky (The Field Museum): "Sickle-clawed dinosaurs of the Southern Hemisphere"
In January, 2004 a joint team of Argentine and American paleontologists excavated the most complete small carnivorous dinosaur yet discovered in South America. The specimen comes from 90 million year old rocks in northern Patagonian province of Rio Negro about 700 miles southwest of Buenos Aires. It represents a new species, which we named Buitreraptor, and it is very bird-like relative of Velociraptor with a huge wish-bone, long, wing-like forelimbs, and large sickle-shaped claws on its feet.
Q & A
3:30 PM Break
4:00 PM Xu Xing (Institute for Vertebrate Paleontology and Paleoanthropology): "In search of BirdŐs Ancestors"
Dr Xu Xing considers himself to be the luckiest of dinosaur fossil hunters. Based on his personal experiences, he will relate stories of prospecting dinosaur fossils in remote areas of China and elsewhere. He has discovered exceptionally well-preserved skeletons which have become keys for understanding the dinosaur-bird transition, and has analyzed and discerned patterns of dinosaur evolution along the line to birds. The new dinosaurs unearthed are probably among the weirdest and most important dinosaur species ever known.
5:00 PM Peter Larson (Black Hills Institute of Geological Research): "Variation and Sexual Dimorphism in Tyrannosaurus rex"
Over the last one hundred plus years more than thirty specimens of Tyrannosaurus rex have been collected. Although this would be a small number of specimens, compared to what might be acceptable for an extant species, it is significant when compared to other extinct taxa of non-avian dinosaurs. Identification of certain characters, along with morphometric analysis of specific skeletal elements, indicates that robust and gracile morphotypes exist. Sexual dimorphism studies for extant birds demonstrate that weight and some skeletal characters differ by gender. This data along with ancillary information obtained from theropod nests and Tyrannosaurus rex skeletons suggest that the robust morphotype is female. Morphometrics and further study indicate that specimens that have been synonymized probably represent at least two additional taxa distinct from T. rex. Those are Nanotyrannus lancensis and an unnamed species of Tyrannosaurus.
6:00 PM End of day 2