Placoderms
Placoderms are an extinct group of armored prehistoric fish that represent some of the earliest jawed vertebrates (gnathostomes). They first appear in the Silurian and become highly diverse during the Devonian, a period sometimes called the age of fishes. The most distinctive feature of placoderms is their extensive dermal armor, consisting of large bony plates that shield the head (head shield) and the front part of the trunk. The presence of jawed mouths makes placoderms important for understanding early gnathostome evolution, as their jaws developed from the anterior gill arches.
Anatomical diversity within Placodermi is considerable. Some members, such as the antiarchs, wore heavy armor over
Ecology and distribution of placoderms were widespread in marine and freshwater environments during the Devonian. They
Placoderms are important for understanding the early evolution of jaws and paired fins in vertebrates. They