Placodermi: Origin and Occurrence | Vertebrates | Chordata | Zoology
In this article we will discuss about:- 1. Occurrence of Placodermi 2. Features of Placodermi 3. Classification 4. Biological Significance. Occurrence of Placodermi: In the Silurian, some 450 million years ago, as the ostracoderms were disappearing, a host of more efficient and jawed fishes appeared. Earlier grouped in a single category, they are now placed into two separate classes- Placodermi [...]