shark skeletons have evolved a cartilage skeleton that is lighter than bone and is much more flexible. It allows them to twist and bend their bodies much more quickly and dramatically than they would be able to if they had the kind of dense, solid bones that are found in bony fishes. That flexibility helps sharks find prey and evade predators.
Unlike a mammal’s teeth, which are rooted in the jaw bone, sharks’ teeth are planted within their gums. This means that a shark’s lost teeth will be naturally replaced. The fact that a shark’s teeth are not rooted in its bones also helps it to lose them more easily without causing pain or discomfort to the shark.
Unveiling the Mysteries of Shark Skeletons: What Lies Beneath the Surface
The cartilage in a shark’s body is stronger than the bones in a human or any other vertebrate. It is reinforced by a network of cartilaginous tissue fibers that surround the shark like a corset, and it acts as an outer skeleton. This cartilaginous corset, which also functions as a kind of vascular system for the shark, stores energy and releases it at the end of a tailbeat.
Scientists have recently sequenced the genome of an elephant shark, revealing that members of this species lack one of the genes that turns cartilage into bone in other vertebrates. This finding supports the idea that the last common ancestor of sharks and bony vertebrates did have bones, but lost the ability to form them over time. The discovery may help scientists better understand the evolution of bone-forming genes.
