Block of turtle layer.

Block of turtle fossils during preparation. Credit: Copyright Museum fur Naturkunde Berlin

A spectacular find of about 1,800 fossilized turtles from the Jurassic era has emerged from northwestern China’s Xinjiang province, according to German paleontologists.

“Bones upon bones, we couldn’t believe our eyes,” Oliver Wings, paleontologist and guest researcher at the Museum für Naturkunde in Berlin, said.

Wings and Walter Joyce, a fossil turtle specialist at the University of Tubingen,  have been working with Chinese paleontologists at the site since 2008.

“This site has probably more than doubled the known number of individual turtles from the Jurassic. Some of the shells were stacked up on top of one another in the rock,” Joyce said, describing the discovery as what paleontologists refer to as a “bone bed.”

Wings, Joyce and their team have made several expeditions to the arid region since 2007, finding fossil sharks, crocodiles, mammals and several dinosaur skeletons.

Now one of the world’s driest regions, 160 million years ago Xinjiang was a green place of lakes and rivers, bursting with life. Yet the scientists have shown that even then, conditions were not always ideal, with climate change leading to seasonal drought – and this remarkable fossil find.

The turtles had gathered in one of the remaining waterholes during a very dry period, awaiting rain. Today’s turtles in Australia for instance do the same thing.

But for the Xinjiang turtles, the rain came too late. Many of the turtles were already dead and their bodies rotting. When the water arrived, it came with a vengeance: a river of mud, washing the turtles and sediments along with it and dumping them in one place, as the paleontologists read the site and its layers of stone.

The large number of turtles allows the researchers to make a first statistical analysis of Asian turtles in the Jurassic period. Their simultaneous death and preservation makes it possible to compare variability, growth, and morphological differences among the species.

Source: Oliver Wings, Márton Rabi, Jörg W. Schneider, Leonie Schwermann, Ge Sun, Chang-Fu Zhou, Walter G. Joyce. An enormous Jurassic turtle bone bed from the Turpan Basin of Xinjiang, China. Naturwissenschaften, 2012; DOI: 10.1007/s00114-012-0974-5