What is "drepanaspis"

Drepanaspis is an extinct genus of primitive jawless fish from Early Devonian marine strata of Europe. D. gemuendenensis, of the Hunsrück lagerstätte is the best known, and most thoroughly studied species, as it is known from several articulated specimens. It was a flattened creature with a heavily armored body, superficially ray-like in appearance. Its mouth faced upwards, unlike most other Heterostracans, which had downward-facing mouths. Drepanaspis also had small, widely spaced eyes. It is presumed to have foraged the ocean floor for food.

This frying-pan shaped fish may have been the ancestor of the giant, meter-long, meter-wide Psammosteid heterostracans of the late Devonian.