HARRISBURG, Pa. (WHTM) — Dr. Steven Jasinski, a professor at Harrisburg University’s Science and Technology department has identified a previously unknown extinct species of the painted turtle, dating from five million years ago, which may offer clues to what’s going to happen to the turtles of our time.
Get daily news, weather, breaking news and alerts straight to your inbox! Sign up for the abc27 newsletters here
Dr. Jasinski named and described the new fossil species Chrysemys corniculata, or the “horned painted turtle.” (The “corn” part of corniculata refers to the horns.) But the horns of the “horned painted turtle” aren’t actually horns; the species name refers to a conspicuous pair of pointed, horn-like projections located on the front of the shell, right above the turtle’s head and neck. They are similar to “horns” found on the males of modern painted turtles but bigger.
The turtle was discovered at the Gray Fossil Site, located in Tennesee. It’s one of just a few fossil locations in the Appalachian Highlands surviving from the Miocene-Pliocene transition, which happened 5 to 4.5 million years ago. It probably formed when an underground limestone cave collapsed, creating a sinkhole pond. Paleontologists have found hundreds of plants and animals, including the saber-tooth cat, alligator, tapir, rhinoceros, short-faced bear, mastodon, and lots and lots of turtles.
According to Dr. Jasinski, who’s conducted some of the diggings at the site, Gray Fossil was home to at least eight species of turtles. “It is an amazingly unique fossil site and important for our understanding of turtle evolution at a unique place and time,” he says.
Scientists at Gray have found a lot of well-preserved Chrysemys corniculata shells, which allowed Dr. Jasinski to make a very detailed description of the species. He discovered something that sets them apart from modern painted turtles.
“A big difference in Chrysemys corniculata is that the ‘horns’ are present in both sexes, although they appear to be larger in males. It is likely they were sexual display features.”
Painted turtles weren’t the only kind in the pond. It also contained slider turtles and snapping turtles. (A few years ago, Dr. Jasinski named the Gray site slider turtle Trachemys haugrudi, or “Haugrud’s slider turtle.”) So what drove the horned painted turtle to extinction? Dr. Jasinski suspects it was other painted turtles.
“Chrysemys corniculata may have preferred slightly warmer temperatures,” he explains. “As conditions changed, C. picta (modern painted turtles) were potentially able to overtake the other species, making them the most widespread turtles in modern North America.”
Scientists analyzing the evolutionary relationships of the turtles at Gray Site have found some disturbing trends for modern turtles. Jasinski discovered temperatures may have an effect on how often turtles evolve into new species. His studies suggest painted turtles go through more speciation during cooler periods, and less speciation when things get warmer. “It is possible that as conditions become warmer moving forward with current climate change conditions,” said Jasinski “these turtles may end up being more at risk.” Since turtles are already some of the most at-risk reptiles now, any sort of added pressure is bad news.
“While painted turtles aren’t endangered today,” said Jasinski, “this study suggests that they may eventually follow the path of other turtles that are already having a hard time dealing with conditions today. I only hope this can be another potential call to be proactive for conservation rather than reactive, because if we continue to wait for more turtles to become endangered, it may be too late.”
This research was published in the “Zoological Journal of the Linnean Society” by Jasinski, who teaches Environmental Sciences and Sustainability at the University and is an alumnus of East Tennessee State University’s paleontology master’s program. To read the scientific paper describing Chrysemys corniculata, visit this link.
Gray Fossil Site and Museum is open to the public. For more information, click here.