UTM’s fossil collection grows by ‘trilobites’
Posted: Wednesday, August 8, 2012 6:00 pm
The Messenger 08.08.12
The University of Tennessee at Martin’s fossil collection recently grew in size and quality with the donation of a trilobite collection.
George Stone of Carterville, Ill., made his second gift of museum-quality trilobites to the university, with the collection accepted by Dr. Michael Gibson, professor of geology.
Stone made his first fossil donation to the university in 2009.
Trilobites, a “living fossil” related to today’s horseshoe crabs, are part of a fossil group of extinct marine arthropods that form the class Trilobita. Trilobites first appeared in the fossil record during the Early Cambrian period (540 million years ago),thrived throughout the lower Paleozoic era before facing near extinction when, during the Devonian, all trilobite orders, with the sole exception of Proetida, died out. Trilobites finally disappeared in a mass extinction at the end of the Permian about 250 million years ago.
This collection came from a site in Pike County, Mo., and was found in Maquoketa Shale deposited when Illinois was a tropical muddy sea. These trilobites belong to the genus Isotelus, several species of which are sometimes found in Middle and East Tennessee. The collection is noteworthy because of unusually good preservation, even after 450 million years.
Most of the specimens are complete, meaning the animals did not go through the typical molting stage to shed their shells to grow larger, a process that usually fragments the exoskeleton like modern horseshoe crabs. Most likely, this is caused by rapid burial on the ancient seafloor, what paleontologists call an “obrution deposit.” The good preservation makes teaching trilobite anatomy and physiology to students much easier.
Stone has donated spec-imens to universities and museums in multiple states. He began collecting Isotelus in 1983 and his wife, Janet, retired deputy director of health protection for the state of Illinois, joins him frequently on fossil searches.
Gibson said Stone’s generosity benefits the university in several ways.
“We get some of the best specimens to work with to teach,” he said, noting that his current students are studying specimens previously donated by Stone. “There are only three paleontology programs in West Tennessee and we’ve got the one with the most courses in it right now.”
The specimens are also used for teacher professional development and for other public work.
“The other thing for us is most of our fossil record is way younger,” Gibson added. “We’re dinosaur time here in West Tennessee. This (donation) is significantly older: two, three times, four times older than that. So it allows us to round out our history of life collection tremendously.”
Stone’s donation joins several other fossil collections that reside at UT Martin. The Stone trilobites will be featured in a display in the university’s Joseph E. Johnson Engineering Physical Sciences Building and also loaned to Discovery Park of America.