BSCS Biology: A Molecular Approach
The Cell: Homeostasis and Development
In the News
T. rex Fossil Yields Surprising Discovery
The unusual problem of trying to fit a huge dinosaur thighbone into a helicopter
has led to a landmark scientific finding.
Paleontologists discovered the Tyrannosaurus rex fossils in a remote
part of Montana in 2003. The carnivore
lived about 68 million years ago, and its remains were locked in sandstone.
After the bone was discovered, the fossil-hunting team prepared to move it
to a lab in Bozeman, Montana for study. The 3.5-foot-long bone, still encased in rock, was
too large to fit in the helicopter. So, the paleontologists had to break the
bone in half for the trip.
Because the bone was broken, scientists had a chance to examine the fossil
before they applied the chemical preservatives used to treat most samples.
They noticed unusual tissue fragments inside the marrow cavity. These tissues
would have been destroyed if the preservatives had been applied first.
It is rare that any kind of evidence of soft tissues is found in fossils.
And when it is, the tissues usually have been replaced by minerals during
permineralization. Therefore, this discovery was particularly noteworthy.
Working carefully, researchers managed to dissolve the minerals deposited
inside the tissues. A stretchy, pliable substance remained.
The researchers published their findings in the March 2005 issue of the journal
Science. They reported that the substance appears to be a network of
blood vessels. The scientists were able to squeeze microscopic dark spheres
from the vessels and came to the initial conclusion that the spheres were
erythrocytes (red blood cells). They also observed that some of the preserved
tissues appeared to contain osteocytes (mature bone cells).
What are the implications of these findings? First, researchers are already
beginning to use the new extraction methods on other well-preserved fossils.
They have recovered tissues from two other T. rex fossils and the remains
of a hadrosaur, a plant-eating dinosaur. Second, the findings might lead to
important studies in dinosaur physiology and biochemistry. Third, and perhaps
most important, the discovery may bring scientists one step closer to extracting
proteins − and even DNA − from fossils.
Most scientists agree that they are still a long way from comprehensive genetic
studies of dinosaurs. However, these recent discoveries open up new possibilities
for greater understanding of dinosaurs in the future.