Raleigh, N.C. — Paleontologists with North Carolina State University reported on Thursday their findings after seven years of study of an ancient, giant species of turtle.

The Carbonemys cofrinii, or “coal turtle,” was discovered in 2005 in a coal mine. It has a shell 5 feet 7 inches long and a skull the size of a regulation football.

The huge reptile lived in South America about 60 million years ago.

Edwin Cadena, the N.C. State graduate student who made the discovery, explained his find at the North Carolina Museum of Natural Sciences Thursday afternoon.

“We had recovered smaller turtle specimens from the site. But after spending about four days working on uncovering the shell, I realized that this particular turtle was the biggest anyone had found in this area for this time period – and it gave us the first evidence of giantism in freshwater turtles,” he said.

The find is the only one of its kind. Dr. Dan Ksepka, of N.C. State and the Museum of Natural Sciences, says a turtle that big would preclude other large predators from living in the same territory. “That turtle survives because it has eaten all of the major competitors for resources," he said.

Cadena and Ksepka worked with Carlos Jaramillo, of the Smithsonian Tropical Research Institute in Panama, and Jonathan Bloch, of the Florida Museum of Natural History. Their work was published in the Journal of Systematic Palaeontology.