Chondrichthyes Fossils: Megalodon, Sharks, Rays & kin | Darwin and Wallace: A Nature & Fossil Store

Chondrichthyes Fossils: Megalodon, Sharks, Rays & kin


       The Chondrichthyes (meaning “cartilage fishes” for their completely cartilaginous skeletons) are comprised of the Holocephalans (chimaeras), the Batoids (rays, including skates and sawfish), and the group of fish that are perhaps the most intriguing to all humans: the Selachians (sharks). These animals are not only united by their unique skeletons, but also jaws that evolved from gill arches, as well as paired fins. Another commonality (though absent in chimaeras and electric rays) are the small teeth that cover their bodies, known as dermal denticles. These teeth serve as a stream-lining function in swimming, as well as protection from predators. The earliest (though unconfirmed) evidence of cartilaginous fish comes from Chondrichthyan-like scales of the genus Tantalepis of Australia, which dates back to the Ordovician period, approximately 461-466 million years ago. Genetic evidence has shown that chimaeras diverged from the shark and ray group (known as Elasmobranchs) approximately 421 million years ago, while sharks and rays would diverge from each other approximately 306 million years ago. These fishes are true survivors, as their overall body styles have changed very little over massive amounts of geologic time, and have survived through multiple extinction events.

Click on the images below to see the incredible fossils we offer in our Chondrichthyes selection:

MEGALODON

 Selachii: Sharks