Fossils donated to UT Martin
Posted: Friday, August 3, 2012 2:56 pm
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 sea floor, what paleontologists call an “obrution deposit.” The good preservation makes teaching trilobite anatomy and physiology to students much easier.
Besides UT Martin, Stone has donated specimens to universities and museums in multiple states, including the University of Kansas, Southern Illinois University, the University of Indiana, the University of Tennessee, and the Missouri and Illinois state museums. 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.
Stone, retired as president of the Sangamon State University (now the University of Illinois at Springfield) Foundation, said that his motivation for collecting and donating fossils is “because I love paleontology, and I love trilobites.” He added, “I started collecting trilobites when I was five years old on the shores of Lake Champlain, which is middle Ordovician age.” Gibson said that 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, including the extensive Vanderbilt Fossil Collection.
The Stone trilobites will be featured in a display in the university’s Joseph E. Johnson Engineering Physical Sciences Building and also loaned to the new Discovery Park of America museum in Union City.