|Dinosaurs in Their Time
Field Guide to the Oviraptorosaur
oviraptorosaur differs significantly from all of its nearest
relatives. Its distinctive features indicate that it represents
a previously unknown species of dinosaur. One goal of Carnegie
Museum of Natural History's scientific study of the oviraptorosaur
is to name this new species.
oviraptorosaurs belong to the group Oviraptoridae [OH-vih-RAP-tor-ih-day],
which includes the infamous "egg-thief" Oviraptor.
However, Carnegie Museum of Natural History paleontologists think that our new dinosaur
belongs to a bizarre, poorly understood group of oviraptorosaurs
called the Caenagnathidae [SEE-nuh-NAYTH-ih-day]. This idea
rests on skeletal features shared by our oviraptorosaur and
other caenagnathids, such as lower jawbones that are fused together,
a hipbone whose forward portion is longer than its rearward
portion, and a middle foot bone whose upper end is "pinched"
between the upper ends of the other two foot bones. The Carnegie Museum of Natural History oviraptorosaur is by far the most complete caenagnathid
in the world, and its study will reveal the anatomy and behavior
of these mysterious dinosaurs for the first time.
Bird, or Both?
its toothless jaws, relatively short tail, long spindly legs,
and three-toed feet, our new oviraptorosaur looks more like
a bird than a typical dinosaur.
than a century, the idea that birds arose from dinosaurs was
hotly debated among scientists. Then, beginning in 1996, a
number of spectacular discoveries from approximately 120-million-year-old
lakebeds in northeastern China effectively confirmed the dinosaur
origin of birds. These discoveries, indisputable dinosaurs
preserved with impressions of feathers attached to their bodies,
have convinced all but the most stubborn skeptics.
are not extinct; they live on! The national symbol of the
United States, the bald eagle, is a highly modified dinosaur.
The ostriches that strut the savannas of Africa are dinosaurs.
The tuxedoed penguins that frolic among Antarctic ice sheets
are dinosaurs. Dinosaurs fly south for the winter. And distant
cousins of Tyrannosaurus rex appear on dinner tables
across America every Thanksgiving!
Egg Thieves: A Case of Mistaken Identity
known oviraptorosaur skeleton, discovered in Mongolia in 1923,
was found atop a clutch of dinosaur eggs thought to belong
to the early horned dinosaur Protoceratops. Paleontologists
therefore concluded that this theropod had died in the act
of raiding a Protoceratops nest. This led to its being
named Oviraptor philoceratops—literally, “egg
thief who prefers horned dinosaurs.” It is from this
dinosaur that the entire oviraptorosaur group takes its name.
1990s, further expeditions to Mongolia turned up many more
dinosaur fossils. However, paleontologists were shocked by
what they found: a supposed “Protoceratops” egg with a baby oviraptorosaur
inside! So the eggs that paleontologists originally thought
belonged to horned dinosaurs actually belonged to oviraptorosaurs.
same time, a spectacular oviraptorosaur skeleton was discovered
with its arms outstretched around a nest. The 22 eggs in this
nest were the same kind as those that contained the baby oviraptorosaur...they
were oviraptorosaur eggs! Since it’s not very likely
that a parent would raid the nest of its own species, that
adult appears to have died guarding its nest.
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