Paleontologists, working with the Senckenberg Research Institute in Frankfurt, Germany, recently shared information about the oldest sea turtle fossil ever discovered. It predates the previous record holder from Brazil, Santanachelys gaffneyi, by at least 25 million years.
A Very, Very Old Sea Turtle
Scientists have clocked this sea turtle in at about 120 million years old, maybe even older. The skeleton is over six feet long–not even close to the record-holding Archelon (see photo above) from South Dakota, which measured over thirteen feet–but still, it’s pretty big.
“Hobby paleontologist,” Mary Luz Parra and her brothers Juan and Freddy Parra, unearthed and collected this particular turtle in 2007, near Villa de Leyva in Colombia. The fossilized shells and bones were almost completely preserved and have since been stored in paleontological collections in Colombia and California.
Dr. Edwin Cadena of the SRI recently examined the skeletons with a Californian colleague and established the age and categorization of the sea turtle fossil. It was placed in the turtle group Chelonioidea, based on “various morphological characteristics,” such as its tropical location and skeletal similarities to modern sea turtles like the Hawksbill and the Green Sea Turtle. Cadena and colleagues also determined from the sediments it was found in that this sea turtle, which they’re calling “Desmatochelys padillai,” lived during the Lower Cretaceous period.
Connecting Evolutionary Dots
The finding is a particularly big deal for paleontologists because of the insight it offers into the Cretaceous period. This period is an especially important era in the evolutionary history of sea turtles, but little is known about it. Desmatochelys padillai could change that.
Scientists know that sea turtles evolved from terrestrial and freshwater turtle species that lived around 230 million years ago. They also believe that the major split between land and sea dwelling turtles occurred during the Cretaceous period. But because the fossils from this time period are few and far between, it is challenging to verify the timing of the split with hard evidence.
Thanks to the Desmatochelys, paleontologists may now be better equipped to trace timelines of evolutionary shifts for the Chelonioidea group and maybe for sea turtles in general.
Cadena and colleagues published their study of the turtle in the latest issue of PaleoBios.