Sharks

Fossilized Shark Tooth

Sharks have been in existence since at least the Ordovician Period over 450 million years ago. This was during the time of vast marine diversity, and little diversity present on land. One of the earliest representations of sharks discovered was Cladoselache, which differs in form from modern sharks, but was still a high-speed predator. The most common discovery related to ancient sharks are their fossilized teeth. As sharks shed thousands of teeth throughout their lifespan, there is a higher chance for one of these teeth to find the right conditions for fossilization; however this often presents a problem of identification. In addition to scattered and mixed teeth findings, many sharks exhibit dignathic heterodonty, or a difference in the upper and lower teeth in addition to parasymphyseal, or a difference in teeth in relation to jaw position. Gender difference are also often translated to the teeth making it hard to identify the species a shark tooth originated from.

From the newest fossil collection at the Heard Natural Science Museum and Wildlife Sanctuary.