Polysternon is a genus of turtles in the extinct family Bothremydidae. It was described by Portis in 1882, and contains the species P. provinciale (originally placed in the genus Pleurosternon), which existed during the Cretaceous of what is now France[1] and a new species, P. isonae, from the Late Maastrichtian of Spain.
^"Iraganaren berri". zientzia.eus (in Basque). 1 June 2007. Retrieved 23 November 2017.
^J. Marmi; Á.H. Luján; V. Riera; R. Gaete; O. Oms; À. Galobart (2012). "The youngest species of Polysternon: A new bothremydid turtle from the uppermost Maastrichtian of the southern Pyrenees". Cretaceous Research. 35: 133–142. Bibcode:2012CrRes..35..133M. doi:10.1016/j.cretres.2011.12.004.