While the common ancestor of vertebrates with synovial joints is still a mystery, the oldest specimen with evidence of these ...

Unlike bony fish, sharks, rays, skates, and chimaeras are cartilaginous fish, meaning their skeletons are made of cartilage, not bone. Their skin is covered with denticles, tooth-like scales that ...

Also known as the rock sturgeon, the lake sturgeon is one of 27 species of sturgeon, a family of bony fish that found around the world that first appears in the fossil record more than 200 million ...