hybodontid

Asteracanthus

Asteracanthus was a 6 foot long hybodont shark which lived from the middle Jurassic Period to the middle Cretaceous Period 165-100 million years ago. Unlike most prehistoric sharks which are known only from teeth, Asteracanthus is also known from some… Read More ›

Lissodus

Lissodus was a prehistoric shark which lived from the early Triassic to the middle Cretaceous Period, about 250 to 110 million years ago, give or take. Named in 1835, it was a member of a group of sharks called the… Read More ›

Polyacrodus

NOTE: This article was originally published on May 4, 2022. On December 30, 2025, it was updated and re-uploaded. Polyacrodus was a genus of prehistoric shark, composed of several species, with fossils found in North America, South America, Europe, Asia, and… Read More ›

Baptanodon

This is Baptanodon, an ichthyosaur which lived during the late Jurassic Period about 160-155 million years ago. During this time, the central part of North America was covered with a body of saltwater known as the Sundance Sea, and Baptanodon… Read More ›