[1] Kornhuber initially classified Carsosaurus as a member of the Aigialosauridae, due to its post-cranial features.

A century later, in 1995,[1] a quantitative analysis including fossils of other species found in the intervening years supported this phylogenetic placement.

It long tail may have served as an emergency rudder, as well as a tool for defence, grasping, climbing, and propulsion.

Its fossil contains what Kornhuber interpreted as the remains of many small fishes, lizards, and possibly amphibians, indicating that Carsosaurus was a hunter that consumed live prey whole.

[6] Their positioning indicates that they would have been born tail-first, to lessen the chance of drowning, as this way their nostrils would emerge last.

The ability of Carsosaurus and other early amphibious aigialosaurs to give live birth would have lessened their dependency on land, allowing their evolution into massive, fully aquatic mosasaurs,[6] which would exist from 98 million years ago until the end of the Cretaceous, 65.5 million years ago.

[8] Other taxa that lived or were likely to have lived in the Komen area during the Upper Cretaceous include Komensaurus (another genus of aigialosaur),[5] Myctophidae (a family of fish whose modern members can be found in deep water throughout the world), hard-shelled molluscs, crustaceans, conifers, and ammonites.