Boreaspis ("Boreas' Shield") is an extinct genus of primitive jawless fish that lived in the Devonian period. Fourteen different species of Boreaspis have been found in sandstone of the lagoons and estuaries of Devonian Spitsbergen. Boreaspis was about 13 centimetres (5.1 in) long, with a tough shield covering its head, and extra protective spikes protruding from the cheek regions. It also had a long spike-like rostrum on its snout, which would have enhanced the fish's hydrodynamics and was probably also used to root out food buried beneath the substrate.