It was named by Othniel Charles Marsh in 1869, but renamed Baptosaurus by Marsh in 1870, who thought the name was already in use (preoccupied) by a fish named Halosaurus. According to modern rules, a difference of a letter is enough and the substitute name is unneeded.
In popular cultureEdit
Halisaurus had a brief cameo in the BBC program Sea Monsters, a spin-off to the critically acclaimed Walking with Dinosaurs. The program suggested that Halisaurus would hide in underwater caves waiting to attack small animals (i.e.Hesperornis).