The Basilosaurus is not believed to have been a lizard as the name (King Lizard) suggests, but rather a type of whale. They grew up to 65 feet long and are the state fossil of both Mississippi and Alabama.

I found these and other fun basilosaurus facts in this ThoughtCo. article
Strauss, Bob. "10 Facts About Basilosaurus." ThoughtCo, Feb. 16, 2021, thoughtco.com/facts-about-basilosaurus-king-lizard-whale-1093325.

Link https://www.thoughtco.com/facts-about-basilosaurus-king-lizard-whale-1093325