Researchers find DNA remains in 6 million-year-old turtle's fossil

Researchers on Thursday (Sep 28) said that they have discovered remnants of DNA in fossilised remains of a sea turtle, which dates back to 6 million years ago and is closely related to Kemp's ridley and olive ridley turtles of today.

This is a rare occurrence of genetic material getting identified in such old fossils of a vertebrate. The researchers stated that some bone cells, known as osteocytes, were preserved exquisitely in the fossil, which was excavated along the Caribbean coast of Panama in 2015.

The fossil is partial and has a relatively complete carapace, the shell of a turtle. However, the rest of the skeleton is missing. The researchers estimated that the turtle would have been around a foot (30 cm) long, when alive.

Palaeontologist Edwin Cadena, the lead author of the study published in the Journal of Vertebrate Paleontology, said that in a few osteocytes, the cell nuclei remained preserved and reacted to a chemical solution which helped the researchers recognise the presence of remnants of DNA.

DNA contains genetic information for the development and functioning of an organism.

ALSO READ |Alabama hospital's first animal patient, a sea turtle, gets CT scan; Images go viral

Add WION as a Preferred Source

"I want to point out that we did not extract DNA, we only were able to recognise the presence of DNA traces in the nuclei," stated Cadena, of Universidad del Rosario in Bogota and the Smithsonian Tropical Research Institute.

DNA generally perishes although it has remained preserved in some ancient remains which were kept in the right conditions. Last year, the researchers reported the DNA discovery from plants and microbes, which dated back to about 2 million years ago, from sediment at the remote northernmost point in Greenland.

Cadena stated that the only older vertebrate fossils, apart from the one of turtle to have been found with similar DNA remnants, were of two dinosaurs - Brachylophosaurus, which lived about 78 million years ago, and Tyrannosaurus, which lived about 66 million years ago.

DNA remnants also found in insects

Cadena stated that DNA remnants were also reported in insects which dated back to tens of millions of years ago.

The turtle belongs to the same genus, Lepidochelys, as two of the seven living species of sea turtles in the world - the olive ridley and the world's smallest sea turtle - the Kemp's ridley, said Cadena.

WATCH |Baby turtles released on Nicaraguan beach

Kemp's ridley, which has a slightly hooked beak and a triangular-shaped head, is primarily found in the Gulf of Mexico. The olive ridley, which looks like Kemp's ridley, has a larger distribution and is generally found in the tropical regions of the Pacific, Indian and Atlantic oceans.

"Each fossil site has specific conditions of preservation that in some cases could have favoured preservation of original biomolecular remains such as proteins and DNA," Cadena stated.

"Maybe in the future and with more studies of this kind, we could be able at some point to sequence very small pieces of DNA and to infer things about their close relatives or involve that information in a broader molecular evolutionary study," added Cadena.

(With inputs from agencies)

You cannow write forwionews.comand be a part of the community. Share your stories and opinions with ushere.

WATCH WION LIVE HERE