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Understanding
the Past
In
this section, visitors can 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 include 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.
Protoceratops
Skull
[Click image to enlarge] |
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.
>
The Desert at Night
> Understanding the Past
> Fossil Preservation in the Gobi
> The Diversity of Life
>
The Fighting Dinosaurs
> Birds: Living Dinosaurs
> The Rise of Mammals
>
Digging Up Dinosaurs
Photos
© AMNH
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