Helicoprion is a shark that swam in the Permian seas about 290 million years ago; it is an unusual shark in that it has a spiral dentition.

Helicoprion is a shark that swam in the Permian seas about 290 million years ago; it is an unusual shark in that it has a spiral dentition.

blog comments powered by Disqus
Follow

Get every new post delivered to your Inbox.

Join 4,070 other followers