Heterostraci genera

Drepanaspis (from 'sickle' and 'shield') is an extinct genus of heterostracan armoured jawless fish from the Early Devonian (approximately 416 - 397 mya). Drepanaspis are assumed to have lived primarily in marine environments and is most commonly characterized by their ray-like, heavily armoured bodies, along with their lack of paired fins and jaws.