Giant turtle 100 times heavier than its closest relative
Males carried horns on their carapace
In some individuals, the complete carapace showed a peculiar and unexpected feature: horns. “The two shell types indicate that two sexes of Stupendemys existed — males with horned shells, and females with hornless shells,” concludes Sánchez. According to the paleobiologist, this is the first time that sexual dimorphism in the form of horned shells has been reported for any of the side-necked turtles, one of the two major groups of turtles world-wide. Despite its tremendous size, the turtle had natural enemies. In many areas, the occurrence of Stupendemys coincides with Purussaurus, the largest caimans. This was most likely a predator of the giant turtle, given not only its size and dietary preferences, but also as inferred by bite marks and punctured bones in fossil carapaces of Stupendemys.
Turtle phylogeny thoroughly revised
Reference: “The anatomy, paleobiology, and evolutionary relationships of the largest extinct side-necked turtle” by E.-A. Cadena, T. M. Scheyer, J. D. Carrillo-Briceño, R. Sánchez, O. A Aguilera-Socorro, A. Vanegas, M. Pardo, D. M. Hansen and M. R. Sánchez-Villagra, 12 February 2020, Science Advances.DOI: 10.1126/sciadv.aay4593
