It was collected from the late Oxfordian-aged locality of Cap d’Aggio-La Turbie, in Nice, France.

[3] Later, Buffetaut (1982) demonstrated that it was in fact a metriorhynchid, closely related to, if not a member of Dakosaurus.

They based this referral on its unusually large dentition (apicobasal length in excess of 6 centimetres or 2.4 inches) that thought to be unique to species of Dakosaurus among all other thalattosuchians.

[1] Aggiosaurus actually has the largest dentition of any known metriorhynchid (up to 12 cm (4.7 in) in apicobasal length), although further phylogenetic analyses found that large robust teeth present also in other geosaurins, such as Torvoneustes.

Young et al. (2012) resurrected the genus name Plesiosuchus for D. manselii (which also present this trait) as their phylogenetic analysis found a paraphyletic Dakosaurus and suggested more basal position for it within Geosaurini than previously thought.