Acta Musei Moraviae

Quaternary evolution of the Grass-snake (Natrix natrix): new evidence

Evolutionary changes of the two cranial elements of the posterior brain-case are observed (basisphenod and prootic) in the living species Natrix natrix since the Lower Pleistocene. It seems to be apparent that the ‘modem’ pattern on the basicranial elements (particularly on the basisphenoid) of the living Natrix natrix, which is the direct descendant of the extinct Neogene species Natrix longivenebrata, were widely evolved as early as at the Plio-Pleistocene transition.