Presenting... Dental Detective Work was a temporary exhibit at OUMNH. The display featured the teeth of ancient sharks and explained how they can be used to identify how extinct animals lived, what they ate, and what they looked like.
Unlike other fish, chondrichthyans (sharks, rays, skates and chimera) don't have bones. Their skeleton is entirely made up of cartilage. Unfortunately, cartilage doesn't preserve well in the fossil record, so palaeontologists who study ancient sharks often have only teeth to work with.
The shape of chondrichthyan teeth is greatly influenced by two main factors: diet and the way they catch their prey. This means that most modern sharks and rays can be used to infer what prehistoric species were eating, and how they lived.
1. Modern Mako jaws (Isurus oxyrhinchus)
2. Fossil lamniform teeth (Lamniformes)
Agile, pursuit predators that primarily hunt soft-bodied prey, like bony fish and other sharks, have rows of sharp, needle-like teeth. Even if we only have isolated teeth of prehistoric sharks, by comparing them to modern species with the same dentition we can infer what they ate and how they hunted.
Modern cow shark jaw (Hexanchus griseus)
Cow sharks have comb-like teeth in the upper jaw, forming a type of cutting dentition. The more robust tooth shape on the lower jaw is for clutching. The mixed dentition allows for a varied diet and cow sharks often inhabit waters where food is scarce.
THE PRESENTING CASE
Nestled alongside the Museum's front desk is the Presenting Case, home to a series of temporary displays and never-before-seen specimens.