order of fishes (fossil)
|Artist's restoration of Pteraspis|
The whole group has the head and front of the body armoured. Delicate, finger-like parts of the plates were at the edges of the mouth. This suggests they were filter feeders taking plankton from the water column..
- Purnell, Mark A. 2002. Feeding in extinct jawless heterostracan fishes and testing scenarios of early vertebrate evolution. Proceedings of the Royal Society of London B: Biological Sciences. 269 (1486) 83-88.