Conjoined twin turtles named "Cotton" and "Kale," taken under protection of a university laboratory after they were found in Turkey's world famous travertines of Pamukkale, have died of multiple organ failure.

Pamukkale University Faculty of Arts and Sciences Biology Department Lecturer Prof. Eyüp Başkale, Serdar Düşen and the doctoral student Ayfer Şirin tried to keep the turtles alive, Başkale told Anadolu Agency (AA).

Stating that they took great care of the conjoined turtles as they prepared for hibernation, Başkale said: "The turtles started to gain weight and there was a noticeable acceleration in their movements. However, their organs could not complete their development because their bodies were attached."

Explaining that the incidence of conjoined twins in turtles was found to be one in 100,000, Başkale said scientific studies on this rare case are continuing.

The conjoined twin turtles were found by a tourist near the Pamukkale travertines on Nov. 10. It was determined that they were of the species Testudo greaca, also known as the "Mediterranean spur turtle."