File photo: Each was clearly a male and a female of the species, scientific name Allaeochelys crassesculpta.

Tuebingen, Germany - Turtles which died while mating have been discovered 47 million years later in German rocks, according to scientist Walter Joyce.

“They were obviously so enthralled that they sank into deeper, poisonous water and died,” said Joyce, who teaches palaeontology at the University of Tuebingen in Germany. “They were in exactly the position that turtles adopt while mating.”

Joyce, who was to publish the findings on Wednesday in the British Royal Society journal Biology Letters, said nine couples had been discovered so far in the Messel Pit, a fossil-rich disused quarry south of Frankfurt which is a Unesco World Heritage site.

Each was clearly a male and a female of the species, scientific name Allaeochelys crassesculpta. They were the oldest fossilised matings ever found. Two of the couples have been put on display in the Senckenberg Museum in Frankfurt.

The rocks of the Messel Pit contain thousands of species of creatures, all believed to have lived in or near a volcanic crater lake where toxic gas and water caused repeated sudden deaths.

The muddy bottom of the lake preserved the remains, which then turned to stone. - Sapa-dpa