Cretalamna (also known as Cretolamna) is an extinct genus of otodontid shark, which lived from about 103 million years ago to about 46 million years ago, from the Late Cretaceous to the Eocene. Many consider it to be the ancestor of the largest sharks that ever lived, Otodus angustidens and Otodus megalodon.
Cretalamna was a medium-sized shark, with a total length estimated at 2.3–3 m. It is thought to have had a spindle-shaped body comparable to that of modern lamniform sharks, as indicated by its circular vertebrae.
Cretalamna teeth are distinguished by a broad central triangular cusp and two smaller lateral cusplets. The edges of the teeth are razor-sharp, while the sides have a smooth surface. Tooth symmetry varies—some exhibit exact bilateral symmetry, while others show high asymmetry. Adjacent teeth do not overlap.
