Unlike its other prehistoric friends, the shark is still swimming the oceans –although today’s sharks look quite different from the ones that lived millions of years ago. What’s more fascinating, is that we are discovering more about the shark’s past every day.
Recently, gulf divers have unearthed teeth from the ancient megalodon shark that is believed to have lived between 2 million and 20 million years ago whilst diving off Venice, Florida. Eco-Photo Explorers travel the world searching the sea bed on research expeditions. The Gulf Coast of Florida is a fruitful place to search for fossils as the water remains shallow way out to the sea.
“It is very murky, one or two foot visibility, and that can drop to zero once you start looking for the teeth,” said diver Michael Salvarezza. “Touch everything, go slow, keep your focus and if you are in doubt, bring it up and we’ll have a look.”
Salvarezza and fellow diver, Christopher Weaver, found the first fossil close to the surface of the sand.
“The first tooth that I found was pretty much laying on the surface. It was at an angle, one of the points of the triangle was sticking out of the sand,” said Salvarezza.
The largest tooth found was around 7.6 cm, meaning the megalodon it came from was around 9-10 metres in length. From what has been discovered about megalodons, these mighty creatures could grow to reach 20-30 metres. Their mouths could measure to be 1.9 metres in both width and height. As sharks are made from easily decomposing cartilage, the only remnants divers can find are the gargantuan teeth.
THE ENEMY OF SHARKS
It’s hard to fathom, but prehistoric sharks had predators who fed on them. The Dimetrodon was the main predator of sharks and the first large predator on land. They were four-legged and had huge sails that distinguished them. They could grow to 4 metres and were the first to have the serrated teeth we see on sharks today. Along with their scary saw teeth, they also had fangs. The era in which it lived was the early Permian Era, 290 million years ago.
This was an era dominated by plant-eaters, which the Dimetrodon and its teeth, were not suited for. However, there weren’t enough herbivores for the Dimetrodon and the rest of the carnivores to snack on, prompting it to turn to the sea for prey.
Palaeontologist Dr. Robert Bakker of the Houston Museum of Natural Science, while digging at Craddock Ranch in Texas,) stated that he found 8.5 of the predators for every one herbivore. The prey that sustained the Dimetrodon hadn’t fossilised, thus, Bakker and his team realised the prey must have been sharks; specifically, Xenacath sharks, of which 60 were found.
But sharks, being predators as well, fought back. Bakker has found bites on Dimetrodon bones that match that of shark teeth, showing us that sharks have always been apex predators.
If you love sharks as much as we do (impossible, but you can try), visit them in their natural habitat by shark cage diving and spread the word about how important they are.
Visit Shark Bookings for shark cage diving tours in South Africa.