Fossil of Turtle With Extremely Circular Tire Sized Shell Discovered

Posted on July 11, 2012

Drawing of Puentemys mushaisaensis - Turtle with round shaped shell

Paleontologist Carlos Jaramillo's group at the Smithsonian Tropical Research Institute in Panama and colleagues at North Carolina State University and the Florida Museum of Natural History have discovered the fossil of a previously unknown turtle species in northwestern South America. The turtle, which lived 60 million years ago, has a unique circular shell.

The new turtle species is named Puentemys mushaisaensis because it was found in La Puente pit in Cerrejon Coal Mine, a place made famous for the discoveries, not only of the extinct Titanoboa, the world's biggest snake, but also of Carbonemys, a massive freshwater turtle as big as a smart car.

The most peculiar feature of this new turtle is its extremely circular shell, about the size and shape of a big car tire. Edwin Cadena, post-doctoral fellow at North Carolina State University and lead author of the paper, said that the turtle's round shape could have discouraged predators, including Titanoboa, and aided in regulating its body temperature.

The researchers say the width of the turtle's shell probably exceeded the maximum expansion of the Titanoboa's mouth. They also say the circular, low-domed shape would have increased the area of the body exposed to the sun, helping the cold-blooded turtle warm to a temperature at which it was more active.

Fossil of Puentemys mushaisaensis - Turtle with round shaped shell

The team's findings have been published in the Journal of Paleontology.

Images: Artwork: Liz Bradford, Photo: Edwin Cadena

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