JAKARTA – DNA remains have been found in the fossil remains of a turtle dating from 6 million years ago which is closely related to the Kemp’s ridley and olive ridley turtles. This finding marks one of the rare genetic materials that have been identified in this ancient vertebrate fossil turtle, researchers said on Thursday, September 28, 2023.
The researchers said some bone cells, called osteocytes, were well preserved in the fossil, which was unearthed along Panama’s Caribbean coast in 2015. The fossil was only partial, with a relatively complete carapace – a turtle’s shell – but not the entire skeleton. The turtle was estimated to have been about a foot (30 cm) long when it was alive, they said.
In some osteocytes, the cell nuclei were preserved and reacted to chemical solutions that allowed the researchers to recognize the presence of remnants of DNA, the molecule that carries genetic information for an organism’s development and function, said paleontologist Edwin Cadena, lead author. from research published in the Journal of Vertebrate Paleontology.
“I would like to point out that we did not extract DNA, we were only able to recognize the presence of traces of DNA in the nuclei of atoms,” added Cadena, of the Universidad del Rosario in Bogota and the Smithsonian Tropical Research Institute.
DNA is quite easily damaged, although under the right conditions it has been preserved in some ancient remains. Researchers last year reported the discovery of DNA from animals, plants and microbes dating to about 2 million years ago from sediments at Greenland’s northernmost point.
Cadena said the only vertebrate fossils older than the newly described turtle that were found with similar DNA remains were two dinosaurs – Tyrannosaurus, which lived about 66 million years ago, and Brachylophosaurus, which lived about 78 million years ago. Cadena said DNA remains have also been reported in insects dating back tens of millions of years.
The turtle is from the same genus – Lepidochelys – as two of the world’s seven living turtle species – the Kemp’s ridley turtle, the world’s smallest turtle, and the olive ridley turtle, Cadena said. Kemp’s Ridley, with its triangular head and slightly hooked bill, is primarily found in the Gulf of Mexico. The olive ridley, which closely resembles the Kemp’s ridge, has a wider distribution, mainly found in tropical areas of the Pacific, Indian, and Atlantic Oceans.
The fossil represents the oldest member of Lepidochelys and helps shed light on the genus’s poorly understood evolutionary history, the researchers said. They didn’t identify it by species because the remains were too incomplete, Cadena said.
“Each fossil, each fossil site has specific preservation conditions that in some cases favor the preservation of original biomolecular remains such as proteins and DNA,” Cadena said.
“Perhaps in the future and with more research of this kind, we will one day be able to sequence very small pieces of DNA and infer things about their close relatives or involve that information in broader studies of molecular evolution,” added Cadena .
2023-09-29 21:04:00
#DNA #Remains #Million #Year #Turtle #Fossil
