Evidence of a 'lost world': Antarctica yields two unknown dinosaur species
 Against incredible odds, researchers working in separate
sites, thousands of miles apart in Antarctica have found what they believe are
the fossilized remains of two species of dinosaurs previously unknown to
science.
One of the two finds, which were made less than a week apart, is an early
carnivore that would have lived many millions of years after the other, a
plant-eating beast, roamed the Earth. One was found at the sea bottom, the other
on a mountaintop.
Journey to the bottom of the sea
Working on James Ross Island off the coast of the Antarctic Peninsula,
veteran dinosaur hunters Judd Case, James Martin and their research team believe
they have found the fossilized bones of an entirely new species of carnivorous
dinosaur related to the enormous meat-eating tyrannosaurs and the equally
voracious, but smaller and swifter, velociraptors that terrified movie-goers in
the film "Jurassic Park."
Features of the animal's bones and teeth led the researchers to surmise the
animal may represent a population of carnivores that survived in the Antarctic
long after they had been succeeded by other predators elsewhere on the globe.
"One of the surprising things is that animals with these more primitive
characteristics generally haven't survived as long elsewhere as they have in
Antarctica," said Case, dean of science and a professor of biology at Saint
Mary's College of California who discovered the bones. "But, for whatever
reason, they were still hanging out on the Antarctic continent."
Case said the shape of the teeth and features of the feet are characteristic
of a group of dinosaurs known as theropods, which includes the tyrannosaurs, as
well as all other meat-eating dinosaurs. The theropods, or "beast-
footed" dinosaurs, make up a large and diverse group of now- extinct
animals with the common characteristic of walking on two legs like birds. Recent
research has shown that birds are direct descendents of theropods.
The remains include fragments of an upper jaw with teeth, isolated individual
teeth and most of the bones from the animal's lower legs and feet. The creature
likely inhabited the area millions of years ago when the climate and terrain
were similar to conditions in today's Pacific Northwest and radically different
than they are today.
Martin, curator of vertebrate paleontology at the South Dakota School of
Mines & Technology, said the size and shape of the ends of the lower-leg and
foot bones indicate that in life the animal was a running dinosaur roughly 1.8
to 2.4 meters (6 to 8 feet) tall.
The excavations were supported by the National Science Foundation (NSF), the
independent federal agency that supports fundamental research and education
across all fields of science and engineering. NSF manages the U.S. Antarctic
Program, which coordinates almost all U.S. research on the southernmost
continent and in the surrounding oceans.
The field party included representatives of Argentina's Museo de La Plata,
Minot State University, the University of Oklahoma, the South Dakota Geological
Survey and graduate students from University of California, Riverside and the
South Dakota School of Mines & Technology.
Luck played a major role in the find.
First, relatively few dinosaur fossils from the end of the Cretaceous Period,
which lasted from 144 million to 65 million years ago, (the second half of the
so-called "Age of Dinosaurs"), have been found in Antarctica. Second,
the specimen was an exceedingly rare find and one of only six dinosaur fossils
that have been discovered in the James Ross region of the Antarctic Peninsula,
the landmass that juts north from the southernmost continent towards South
America. Also, to have been preserved at all, the animal likely floated from the
shore out to sea after it died roughly 70 million years ago and settled to the
bottom of what was then a very shallow area of the Weddell Sea.
The team concentrated its investigations on the Naze, a northerly projecting
peninsula, where exposed materials represent a period at the end of the Mesozoic
Era, a span of time between 248 million to 65 million years ago that includes
the Cretaceous Period. At that time, the area was covered by the waters of the
continental shelf, roughly 100 to 200 meters (300 to 650 feet) deep.
If confirmed as Case and Martin expect, the new species is only the second
Antarctic theropod from the late Cretaceous Period.
Journey to the top of a mountain
The pelvis of what researchers believe is a previously
unknown plant-eating dinosaur exposed on the rock where it
was preserved. Credit: William Hammer / NSF
At the same time, thousands of miles away, a research team led by William
Hammer of Augustana College in Rock Island, Ill., was working in the Antarctic
interior on a mountaintop roughly 3,900 meters (13,000 feet) high and near the
Beardmore Glacier. They found embedded in solid rock what they believe to be the
pelvis of a primitive sauropod, a four-legged, plant-eating dinosaur similar to
better-known creatures such as brachiosaurus and diplodocus. Now known as Mt.
Kirkpatrick, the area was once a soft riverbed before millions of years of
tectonic activity elevated it skyward
Also a veteran dino hunter known for his discovery of Cryolophosaurus ellioti
in 1991, Hammer had returned to the site of that find to continue his work,
which had been halted in part because the Cryolophosaurus excavation had dug far
into a cliff face, creating a potentially dangerous overhang. Specialized
workers were flown into the research camp at Beardmore Glacier to remove the
overhang and make it safer to continue the excavations.
As Hammer and his team waited, Peter Braddock, a mountain safety guide on
Hammer's team, scoured the area, informally looking for fossils.
"I jokingly said to him, 'Keep your eyes down, look for weird things in
the rock'," Hammer said. "He had marked four or five things he thought
were odd, including some fossilized roots. But I realized that one of these
things was bone: part of a huge pelvis and illium and much, much bigger than the
corresponding bones in Cryolophosaurus."
Based on field analysis of the bones, Hammer and his fellow researchers
believe the pelvis-roughly one meter (three feet) across-is from a primitive
sauropod that represents one of the earliest forms of the emerging dinosaur
lineage that eventually produced animals more than 30 meters (100 feet) long.
Basing his estimates on the bones excavated at the site, Hammer suggests the
new, and as-yet-unnamed creature was between 1.8 and 2.1 meters (six and seven
feet) tall and up to nine meters (30 feet) long.
Hammer said that the rocks in which the find was made helped to establish
that the creature lived roughly 200 million years ago, millions of years before
the creature Case and Martin discovered on the Antarctic Peninsula. Hammer said
several lines of evidence point to the conclusion that his and the discovery by
Case and Martin represent two new species yielded up by the rocks of the
"Harsh Continent."
"This site is so far removed geographically from any site near its age,
it's clearly a new dinosaur to Antarctica," Hammer said. "We have so
few dinosaur specimens from the whole continent, compared to any other place,
that almost anything we find down there is new to science," Hammer said. -
[NSF]
More information:
NSF Media Contact: Peter West, 703-0292-8070, pwest@nsf.gov
NSF Home Page: http://www.nsf.gov/
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