Physogaleus is a small prehistoric shark

Shark

Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

 that lived in the Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

.

In popular culture

It was featured in the book adaptation of the 2003 BBC series Sea Monsters, a spin-off to Walking with Dinosaurs

Walking with Dinosaurs

Walking with Dinosaurs is a six-part documentary television miniseries that was produced by BBC, narrated by Kenneth Branagh, and first aired in the United Kingdom, in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that...

(1999). In the book, it tried to steal the kill of a Basilosaurus

Basilosaurus

Basilosaurus is a genus of cetacean that lived from in the Late Eocene. Its fossilized remains were first discovered in the southern United States . The American fossils were initially believed to be some sort of reptile, hence the suffix -"saurus", but later found to be a marine mammal...

, with no results. It may have also appeared in Walking with Beasts, although the companion book identifies the shows' sharks as modern snaggletooth shark

Snaggletooth shark

The snaggletooth shark, Hemipristis elongatus, is a species of weasel shark, family Hemigaleidae, and the only extant member of the genus Hemipristis. It is found in the Indo-West Pacific, including the Red Sea, from southeast Africa to the Philippines, north to China, and south to Australia, at...

s.