Aigialosauridae
| Aigialosauridae | |
|---|---|
| |
| Skull of Opetiosaurus | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Clade: | †Mosasauria |
| Superfamily: | †Mosasauroidea |
| Family: | †Aigialosauridae Kramberger, 1892 |
Genera
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Aigialosauridae (from
The family is recognized as containing two species, normally classified into two genera;
Description
Aigialosaurids were semi-aquatic lizards that inhabited shallow marine environments in the ancient Tethys Ocean, the only known fossils having been recovered from Croatia. Their skulls are similar to the skulls of more derived mosasaurs, though the postcranial skeleton is far more similar to that of terrestrial lizards.[4]
Classification
The systematics and taxonomy of the Aigialosauridae is controversial and has a problematic history.[5] Despite thorough reviews of the relationships between early Mosasauroidea and redescriptions of the two normally recognized aigialosaurid genera, Aigialosaurus[6] and Opetiosaurus,[7] the status of the family remains uncertain.
Dutchak & Caldwell (2009) designated Opetiosaurus as a junior synonym of Aigialosaurus (as Aigialosaurus bucchichi),[7] which suggested a very close relationship between the two. Their own analysis does not strictly support such a conclusion,[5] and neither do subsequent analyses. Indeed, analyses done by Madzia & Cau (2017) show that the two genera are not necessarily more closely related to each other than either is to more derived mosasauroids, suggesting not only that Opetiosaurus is a valid genus, but also calling the validity of the Aigialosauridae as a monophyletic group into question.[5]