Besanosauridae

Besanosauridae is an extinct family of ichthyosaurs, marine reptiles that lived during the Triassic period. These reptiles were characterized by their streamlined bodies, dolphin-like appearance, and paddle-like limbs adapted for swimming. The family is primarily known from fossils found in the Besano Formation of Italy, which dates to the Middle Triassic epoch. The namesake genus, Besanosaurus, is the most well-known member.

Members of Besanosauridae are considered to be among the earliest and most primitive ichthyosaurs. They retained some ancestral features, such as a relatively long skull and less specialized pectoral fins compared to later ichthyosaur groups. Their diet likely consisted of small fish and invertebrates, which they would have pursued in the shallow marine environments of their time. The discovery of Besanosauridae fossils has been crucial in understanding the evolutionary history and diversification of ichthyosaurs during the Triassic. Their existence provides evidence for the rapid adaptation of reptiles to marine life following the Permian-Triassic extinction event. The family's limited geographical distribution to the Tethys region suggests that early ichthyosaur radiation may have been influenced by regional paleogeography.