Any pachyostosis of the ribs is absent in Serpianosaurus specimens.

The bones of the postcranial skeleton are thick, having undergone pachyostosis.

There is no pachyostosis, or bone thickening, in the vertebrae and ribs.

These therapsids are classified by their skull pachyostosis, body size, and herbivory.

The pachyostosis seen in the bones of Mesosaurus may have enabled it to reach neutral buoyancy in the upper few meters of the water column.

Pachyostosis is a condition in vertebrate animals in which the bones experience a thickening, resulting in unusually solid bone structure with little to no marrow.

Like other sirenians, the dugong experiences pachyostosis, a condition in which the ribs and other long bones are unusually solid and contain little or no marrow.

These plates as well as the ventral gastralia and the tendency for pachyostosis would have added considerable weight to hupehsuchians, allowing them to have neutral buoyancy.

Most dinocephalians also developed pachyostosis of the bones in the skull, which seems to have been an adaptation for intra-specific behaviour (head-butting), perhaps for territory or a mate.

Although hesperornithiforms probably lost their flight abilities by the end of the Early Cretaceous, minimal pachyostosis in Brodavis suggests the possibility of some volant abilities.

Although not as specialized as Mesosaurus for living in the water, Piveteau noted its short neck, short manus, well developed haemal spines and slight pachyostosis of the ribs.

The small overall size, underdevelopment of the tarsal ossifications, less pachyostosis extent, and larger proportional size of the tibia and fibula are all possible traits of a juvenile.

Paleontologists believe the presence of pachyostosis (thickening of the roof of the head) indicates a "head-butting" behavior of these dinocephalians, probably for protecting territory and fighting over a mate.

Recently described embryos show that pachyostosis of the ribs (which were thicker and denser than in terrestrial tetrapods) developed even before hatching, which suggests that mesosaurs were able to swim at birth, or shortly thereafter.