Understanding the Past
In this section, visitors could compare conclusions drawn from fossils discovered in the Gobi by Roy Chapman Andrews, the famous Museum expedition leader of the 1920 and 1930s, with results from research led in the 1990s by Drs. Norell and Novacek. These specimens have helped paleontologists piece together the Gobi environment during the Late Cretaceous period, providing clues to the evolution of modern animals. Some of the specimens found by Roy Chapman Andrews on view in this section included an Oviraptor egg, a fragment of the flightless bird Shuvuuia, a Protoceratops skull, and a Velociraptor skull.
Oviraptor Egg On top of one of the nests of dinosaur eggs discovered in 1923 lay the skeleton of an animal thought to be stealing the eggs, Oviraptor philaceratops. In 1993, additional eggs were found in the Gobi that closely resembled those of 70 years earlier. One of the eggs contained a fossilized embryo, which researchers identified as a developing oviraptorid -- a member of the group that includes Oviraptor. Later discoveries of two adult oviraptorids sitting on groups of eggs confirmed that they nested in the manner of modern birds -- transforming the image of Oviraptor from that of egg thief to protective parent.
Shuvuuia One of the more puzzling discoveries of the Central Asiatic Expedition in 1923 was the hind leg and part of a pelvis of a small dinosaur not identified with any known species. Scientists noted that the thigh bone was curved and tapered, in the manner of a bird's. In the 1990s, the American-Mongolian expeditions to the Gobi discovered Shuvuuia deserti, a wingless creature that shares many features with modern birds. Closer analysis enabled a researcher at the American Museum to realize the unidentified 1923 creature was also Shuvvuia. Recently, a new specimen of this birdlike animal was found with fibers that are chemically and structurally identical to modern feathers. Scientists now think that this feathered animal belongs to a group of primitive, flightless birds.
Photos © AMNH
Protoceratops Scientists in 1922 discovered a new dinosaur and recognized that it belonged to the ceratopsians, a group of frilled dinosaurs including the North American Triceratops. They gave this new animal the name Protoceratops andrewsi and thought this primitive ceratopsian, was the ancestor of the more advanced Triceratops. Fossils found after the 1920s reveal that these two ceratopsians lived at roughly the same time, so they apparently are "cousins" descended from a common ancestor.
Velociraptor A skull and handful of fossilized bones found in 1923 belonged to a small dinosaur previously unknown to science. The skull suggested a large brain, and the eye sockets would have held large, watchful eyes. The sharp teeth lining the jaws and long, curved claws clearly indicated a swift-moving, carnivorous dinosaur. Little else was known of Velociraptor for many years. Scientists have learned that dromaeosaurs, the group that includes Velociraptor, are closely related to modern birds.