Pteraspis also had some stiff spikes on its back, possibly an additional form of protection against predators. It is thought to have fed from shoals of plankton just under the ocean surface, and some records are found in association with marine fossils, while some others are found in freshwater environment.
Pteraspis had some robust spines on its back, which might have served as an additional form of protection against predators. It is thought to have fed on shoals of plankton near the ocean surface, and fossil records can be found associated with marine fossils, while other specimens are discovered in freshwater environments.