A pit in Germany has yielded the first fossilized evidence of mating behaviour: copulating turtles preserved about 47 million years ago.

Walter Joyce of the University of Tübingen in Germany and his colleagues analysed the remains of nine pairs of Allaeochelys crassesculpta turtles (pictured). On the basis of anatomical differences, the researchers discerned that each pair comprised one male and one female. In two of the pairs, the partners' tails were aligned, consistent with turtle mating positions.

The researchers propose that the couples began mating in the habitable surface waters of a volcanic lake and met their untimely end as they sank into deeper, toxic waters.


Biol. Lett. http://dx.doi.org/10.1098/rsbl.2012.0361 (2012)