Protaspididae
Encyclopedia
The Protaspididae are an extinct marine family of fish-like vertebrates. The protaspidids existed in the early Devonian
period, representing a transitional form between the Pteraspididae and the Psammosteida, bearing the broad head shield shape of the latter, due to a more benthic (bottom-dwelling) existence.
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
period, representing a transitional form between the Pteraspididae and the Psammosteida, bearing the broad head shield shape of the latter, due to a more benthic (bottom-dwelling) existence.