The Halisaurinae are a subfamily of mosasaurs, a group of Late Cretaceous marine lizards. They were small to medium-sized, ranging from just under 3 meters in Eonatator sternbergi to as much as 8 or 9 meters in Pluridens serpentis. They tended to have relatively slender jaws and small, numerous teeth, suggesting a diet of small fish and other prey. Although the skeleton is primitive compared to other Mosasauridae in many respects, halisaurines had the distinctive hypocercal tail of other mosasaurids suggesting good swimming ability, and they persisted alongside other mosasaurs until the end of
The Halisaurinae are a subfamily of mosasaurs, a group of Late Cretaceous marine lizards. They were small to medium-sized, ranging from just under 3 meters in Eonatator sternbergi to as much as 8 or 9 meters in Pluridens serpentis. They tended to have relatively slender jaws and small, numerous teeth, suggesting a diet of small fish and other prey. Although the skeleton is primitive compared to other Mosasauridae in many respects, halisaurines had the distinctive hypocercal tail of other mosasaurids suggesting good swimming ability, and they persisted alongside other mosasaurs until the end of the Cretaceous. The earliest known remains of halisaurines occur in rocks of Santonian age and the subfamily persists until the latest Maastrichtian. Halisaurines are known from North and South America, Europe, Asia and Africa, indicating a more or less global distribution in the Late Cretaceous. Four genera are currently recognized: Eonatator, Halisaurus, Phosphorosaurus and Pluridens.
== Description == left|thumb|247x247px|Restoration of Halisaurus. The Halisaurinae exhibit several characteristics that suggest they are more primitive than mosasaurs of more derived subfamilies. In particular, their flippers are poorly differentiated, meaning that while better adapted to life in oceans than plesiopedal mosasaur genera like Dallasaurus and Tethysaurus, they were poor swimmers compared to many of their contemporaries. Lacking swimming capabilities are quite surprising considering that most other small mosasaurs were adapted to be fast and nimble. The description of Phosphorosaurus ponpetelegans revealed that Phosphorosaurus was highly specialized to compensate for its lack of hydrophalangy.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).