A new study has revealed that a sea turtle found in Alabama is a new species hailing back from the Late Cretaceous epoch.
Ancestor Of Modern-Day Sea Turtles
Modern-day sea turtles were once thought to have had only one ancestor of the Peritresius clade about 100 to 66 million years ago. The species called Peritresius ornatus lived only in North America albeit few fossils of the Peritresius from the Late Cretaceous epoch had been found in present day southeastern United States.
In a study which was published in the journal PLOS ONE on April 18, researchers analyzed sea turtles fossils dating from between 83 and 66 million years ago that were collected from marine sediments in Mississippi and Alabama.
New Species Of Peritresius
Based on anatomical features, study researcher Drew Gentry, from the University of Alabama and colleagues identified some of these fossils as representing a new species of Peritresius, which they called Peritresius martini after the person who discovered these fossils: George Martin.
The amateur collector and retired USDA soil scientist found the fossil in Lowndes County, Alabama, and decided to donate it to the Alabama Museum of Natural History.
The fossils of P. martini helped scientists fill in a significant gap in the lineage that leads to modern sea turtles. They said that the species serves as an important missing link that directly links the living and extinct species.
"Prior studies have suggested that Peritresius was monospecific, with a distribution restricted to Maastrichtian deposits in North America. However, new Peritresius specimens identified from Alabama and Mississippi, USA, show that the genus contains two taxa, Peritresius ornatus, and a new species Peritresius martini sp. nov," the researchers wrote in their study.
Because Peritresius fossils from Cretaceous epoch had already been found in the southeastern United States, the findings show that Peritresius was distributed across a wider region than scientists previously thought.
Much More To Learn About P. Martini
Much about P. martini, however, is still a mystery because it is known only based on a partial shell and pelvis. The researchers said that they would be able to learn more about this species with the discovery of more complete fossils.
"Without a skull or any of the rest of the skeleton, we don't really know much about how this species would have moved, what it ate or how it lived," Gentry said. "The only way to answer these questions is by finding more complete specimens."
