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New dinosaur discoveries from Utah and Wyoming
From: Ben Creisler firstname.lastname@example.org
Mention of some new dinosaur discoveries from Utah and
Wyoming in a 5-7-02 press release from the Geological
Society of America:
Imagine a one-ton Big Bird à la Sesame Street, but instead
of friendly ?hands,? he has Freddie Claws. That?s
basically what the Therizinosaurid dinosaur looks like
that geologist David Gillette?s team from the Museum of
Northern Arizona (MNA) found in Kane County, Utah.
?This is a one ton plant-eating carnivore with really
bizarre claws,? said Gillette. ?It had slender arms and
really long bones in the hand with bladed claws that look
like sickles. With the sheath, the claws are about 15
In 2001, Gillette?s crew found an almost complete
skeleton, which is a rare find. Some Therizinosaurid
remains found in China caused quite a stir because they
were found with feather-like structures on them. The idea
that these creatures were among the ancestors of birds has
been gaining increased acceptance.
Gillette will present a preliminary report on their
discovery May 7 at the Geological Society of America Rocky
Mountain Section Meeting at the Southern Utah University
He will also report on another uncommon find?skin
impressions of a duck-billed dinosaur known as a
Hadrosaur. Gillette?s group found the impressions while
excavating the dinosaur?s tail in the new Grand Staircase-
Escalante National Monument (GSENM) in Kane County.
?This is the second reported discovery of skin impressions
in Utah,? Gillette said. ?On the global scale, however,
this is a rare occurrence. This was a great discovery,
especially in the context of the Hadrosaur with an
articulated tail--that means the bones were still
connected--that extended from the base of the tail (at the
hips) to near the tip, about 13 feet long. In addition,
the tendons that in life held the tail rigid were still
preserved in life position.?
The Grand Staircase-Escalante National Monument is about
two million acres large and much of it is exposed and
eroded rock, so fossils are usually only found in
unrecognizable bits and pieces. But the MNA discovery was
?The rear half of the body was in beautiful state of
preservation and in articulation. The discovery of the
skin impressions came during the excavation, to our great
delight and surprise,? Gillette said. ?I would describe
the skin as pebbled, with radiating grooves in each bump.
The bumps were polygonal, nearly equilateral diamonds,
pentagons, and hexagons. This texture surely added
strength and toughness to the skin, which in turn would
resist decay following death and burial. The carcass did
not decay much prior to burial, but had to be desiccated
to resist decomposition by bacteria--that is, the local
environment must have been very dry.?
Scott Sampson from the Utah Museum of Natural History will
provide updates on his and his team?s discoveries from
GSENM at the same May 7 session as Gillette?
?Paleontological Research in Grand-Staircase Escalante
National Monument and Surrounding Area.?
Their findings include two previously unknown horned
dinosaurs (ceratopsians), a partial skull of a dome-headed
dinosaur (pachycephalosaur), a partial skeleton of a large-
bodied tyrannosaur that is the first tyrannosaur from this
time period in Utah, and the remains of two previously
unknown giant crocodiles. Research for this project was
funded by GSENM as part of a collaborative paleontological
?Given how little is known of the dinosaurs from GSENM,
chances are high that most of the dinosaur remains
represent species new to science,? Sampson said. ?Now the
goal is to find enough of each of these ancient beasts to
establish that they do represent new species. Our efforts
and those of others over the past several years suggest
that GSENM has perhaps greater potential to yield new and
interesting kinds of dinosaurs than any other region in
Based on different types of Late Cretaceous plants and
animal discoveries in Montana and Alberta versus those
found in New Mexico and Texas, Sampson and others
speculate that Utah may be an important boundary area
between two major "biozones."
?To really understand this paleoecological story, however,
will require a good record from the Late Cretaceous of
Utah,? Sampson said. ?And GSENM will provide that record.?
Brent H. Breithaupt, from the University of Wyoming?s
Geological Museum, will take a look at what he
calls ?Theropod family values? via a ?live-action? glimpse
of their lives through intensive study of over 1,000
dinosaur tracks at the Red Gulch Dinosaur Tracksite in
northern Wyoming. He will present his report May 8 at the
Stratigraphy, Paleontology, Paleobotany, Archaeological
Geology, and History of Geology session at the meeting.
?We have evidence of gregarious carnivorous dinosaurs.
These are groups of animals moving together,? Breithaupt
said. ?Trace fossils such as tracks are unique in that
they actually preserve the activities of ancient animals.
In addition, as we have a very large and statistically
valid database we can make some unique interpretations.
This is important as evidence for gregarious carnivorous
dinosaurs is relatively rare.?
Using data from a variety of resources including aerial
photography of the entire tracksite and close-range
photogrammetric images of a single track, Breithaupt and
his co-authors speculate there were family groups, ranging
from yearlings to adults, interacting near their nesting
area by a shore.
?The data also suggest a certain level of parental care
and the level of dependence of the young dinosaurs, as we
have juveniles traveling with adults? he said. ?From what
we know about dinosaur growth, it appears that they grew
at the same rates as some modern ground birds such as
ostriches and emus. If our dinosaurs represent animals of
different ages of the same species then the smallest ones
can't be very old--a year or perhaps less. Little animals
of this sort probably aren't going to travel long
distances during the first year. Thus, they were probably
relatively near a large ground nesting area. If we accept
the paradigm of theropod dinosaurs being similar to modern
birds, then some of the behaviors and family structures
may be similar as well.?