Diagnosis comes from Muller 2005

Askeptosaurus italicus was named by Nopsca (1925) [Thalattosauriform reptile (Fig. 3) with the following autapomorphies: Fronto-lacrimal contact present; retroarticular process absent. Differs from all other thalattosaurs in the lack of a fusion between postorbital and postfrontal. Differs from all non-askeptosauroid thalattosaurs in the presence of a homogenous dentition, the absence of a diastema, the absence of palatal dentition, the presence of low neural spines, the development of an elongated neck, and the presence of a slender radius.]. Its type specimen is MSNM V3550, a partial skeleton (isolated ilium, as well as a few ribs), and it is a 3D body fossil.