
Halisaurus is an extinct genus of mosasaur named by Othniel Charles Marsh in 1869. The holotype, consisting of an angular and a basicranium fragment discovered near Hornerstown, New Jersey, already revealed a relatively unique combination of features and prompted a new genus to be described. Its name is a portmanteau of the Ancient Greek ἅλς (háls; "sea") and σαῦρος (saûros; "lizard"). It was renamed by Marsh to Baptosaurus in 1870, since he believed the name to already be preoccupied by the fish Halosaurus. According to modern rules, a difference of a letter is enough and the substitute name
Halisaurus is an extinct genus of mosasaur named by Othniel Charles Marsh in 1869. The holotype, consisting of an angular and a basicranium fragment discovered near Hornerstown, New Jersey, already revealed a relatively unique combination of features and prompted a new genus to be described. Its name is a portmanteau of the Ancient Greek ἅλς (háls; "sea") and σαῦρος (saûros; "lizard"). It was renamed by Marsh to Baptosaurus in 1870, since he believed the name to already be preoccupied by the fish Halosaurus. According to modern rules, a difference of a letter is enough and the substitute name is unneeded, making "Baptosaurus" a junior synonym.
Since its description, more complete remains have been uncovered from fossil deposits throughout the world with particularly complete remains found in North America and North Africa. The genus remains a key taxon in mosasaur systematics due to its unique set of features and as the most complete representative of its subfamily, the Halisaurinae.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).