Fossil of an ancient shark that swam in the age of dinosaurs solves centuries-long mystery

During the Cretaceous Period, a genus of sharks with unique teeth roamed the sea, primarily grinding and crushing shelled creatures instead of slicing through them. However, scientists have been speculating about the appearance and characteristics of this ancient shark since its discovery in the 18th century, as only isolated teeth were found in the fossil record. Recently, remains found in limestone quarries in northeastern Mexico have given researchers more insights into the shark’s appearance and its place in the evolutionary tree. The discovery also sheds light on the evolutionary history of modern sharks.