In the Late Eocene Period, between 40 million and 34 million years ago, a "whale-like" species known as Basilosaurus thrived. It was once believed to have been some sort of prehistoric reptile when it was first discovered in the United States during the 19th century. This is the reason Basilosaurus, a name that meaning "king lizard," was given to it in 1834.

This whale was rather large. In actuality, it was about 15 tons and about 70 feet long.

The teeth and jaws of this species showed it to be a carnivorous. Scientists have examined the jaws of this whale.

This particular tooth has been stabilized and has some filled fractures