An X-ray nanotomography reconstruction of the intermedial cartilage of a blacktip shark. The colors indicate the thickness of the struts, with red representing thicker areas and blue indicating ...

Sharks have been evolving for more than 450 million years, developing skeletons not from bone, but from a tough, mineralized form of cartilage. These creatures are more than just fast swimmers—they're ...

The evolution of the shark is not what most people would expect. Instead of sharks evolving from a massive predator, the original creature was a small, leaf-shaped fish. This fish lacked eyes and fins ...