Hemipristis serra is an extinct species of weasel shark which existed during the Miocene epoch.

[1] While today's snaggletooth shark is not very large or dangerous, Hemipristis serra, which lived in the Atlantic Ocean during the Oligocene and Miocene, was considerably larger than its modern-day relative and had much larger teeth.

[citation needed] In the Gatun Formation of Panama, H. serra was contemporary with pups of the large lamniform shark Otodus megalodon, and both it and the great hammerhead are theorized to have preyed on the pups of this larger shark due to their presence within the formation.

Their outstandingly large serrations make it a favorite and unique collectible fossil.

Little else is known about the general appearance of H. serra, as there are no known fossils preserving its cartilaginous skeleton at present.