Question

Who first believed to possess the bony or cartilaginous vertebrae?

Answer 1

Cartilaginous fishes:

1. These fall under the class Chondrichthyes and composed of cartilage as endoskeleton.
2. All bony fish fall under the superclass Osteichthyes and Primarily composed of bone as skeleton.

Jawed fish are the first animals that possess cartilaginous or bony vertebrae. Some important characters are as follows:

1. Vertebrae include the spine and neural arch, the hemal arch, the hemal spine and the centrum, in the caudal region protecting the caudal artery and vein.
2. The centrum could either be fused or composed of a varying number of bones, such as pleurocentra and intercentra.
3. The ribs are associated with the vertebrae, usually in two sets – dorsal and ventral. The fish do not have a sternum.