Harrisburg University Professor Discovers 5 Million-Year-Old Turtle Species ‘Entirely New To Science’

A Harrisburg University of Science and Technology professor has identified an extinct species of painted turtle, one that is entirely new to science.

Dr. Steven Jasinski, a professor at the Harrisburg University of Science and Technology named and described the new fossil species of turtle Chrysemys corniculata, or the “horned painted turtle. The name comes from a conspicuous pair of pointy projections on the front edge of the shell, reminiscent of horns.

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.  

The discovery was found at the Gray Fossil Site, overseen by the Don Sundquist Center of Excellence in Paleontology at East Tennessee State University, which preserves a five-million-year-old ecosystem once home to tapirs, rhinos, mastodons, red pandas, and many more extinct species. 

Among the most common fossil animals found at the site are turtles.  These turtles are represented at Gray by numerous well-preserved shells, allowing for a thorough description of this unique species. 

The “horns” on the shell are similar to those found, to a lesser degree, on the males of modern-day 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,” said Jasinski. “It is likely they were sexual display features.”

These turtles would have been right at home in the ancient pond of the Gray Fossil Site, which also hosted slider turtles, snapping turtles, and other semi-aquatic species. 

Fossil evidence shows that painted turtles have been around for 35 million years, and modern painted turtles are extremely common across the United States, including in Tennessee. 

This new discovery at Gray helps scientists unravel the ancient history of this familiar group of reptiles.

“Chrysemys corniculata may have preferred slightly warmer temperatures,” said Jasinski. “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.”

Chrysemys corniculata is the second new species of turtle from the Gray Fossil Site named by Dr. Jasinski, and the third new turtle overall. 

A few years ago, he named the slider turtle at Gray Trachemys haugrudi, or “Haugrud’s slider turtle.”

“The Gray Fossil Site is home to at least eight species of turtles,” said Jasinski. “It is an amazingly unique fossil site and important for our understanding of turtle evolution at a unique place and time.”

The fossil site represents one of the only fossil localities known of the Miocene-Pliocene transition (5 to 4.5 million years ago) in the Appalachian Highlands. It preserves an ancient sinkhole pond surrounded by a forest largely dominated by oak, hickory, and pine trees, with open grasslands nearby.

The fossil site has had numerous new species named from its fossils. 

“The turtle fauna from Gray is incredibly important and there will probably be several more turtle species named from it once they are more fully studied,” said Jasinski.

Another aspect of the study was analyzing the evolutionary relationships of these pond turtles. Jasinski found these pond turtles appear to go through speciation during cooler times in the past, while warmer conditions suppress speciation in these turtles. 

“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.” 

Turtles are already some of the most at risk and endangered reptiles regarding extinction today.

“While painted turtles aren’t endangered today, this study suggests that they may eventually follow the path of other turtles that are already having a hard time dealing with conditions today,” said Jasinski. “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.”

To read the scientific paper describing Chrysemys corniculata, visit this link or you may email Dr. Jasinski at: sjasinski@harrisburgu.edu and ask for a PDF version.

Jasinski has also been the member of other research teams that have recently named multiple horned dinosaurs from New Mexico, as well as fossil carnivoran mammals from Pakistan and India, and named and described another newly discovered species of softshell turtle.

[Posted: January 15, 2023]  PA Environment Digest