Interesting Science Picture XVI

The story:

“Scientists have collected tens of thousands of fossils at this site in recent decades,” notes co-author Dr. Stephan Schaal of the Senckenberg Naturmuseum in Frankfurt, “but only these turtles are known to occur in pairs, a total of nine so far.” Detailed analysis of the fossil material revealed that each pair consists of a female and male individual. More importantly, even though the males typically face away from the females, the tail of some male individuals can be found wrapped under the shell of the female. “There is no doubt in my mind,” says Dr. Joyce, “These animals died some 47 million years ago in the act of mating. No other vertebrates are known to have died during this important biological process and then been fossilized.”

Source: W. G. Joyce, N. Micklich, S. F. K. Schaal, T. M. Scheyer. Caught in the act: the first record of copulating fossil vertebrates. Biology Letters, 2012; DOI: 10.1098/rsbl.2012.0361