Osteostraci - Cephalaspidiformes - Cephalaspididae
Parent taxon: Cephalaspis according to White and Toombs 1983
Sister taxa: Cephalaspis acadica, Cephalaspis agassizi, Cephalaspis campbelltonensis, Cephalaspis canadensis, Cephalaspis dawsoni, Cephalaspis gabrielsei, Cephalaspis jexi, Cephalaspis laticeps, Cephalaspis lewisii, Cephalaspis lightbodii, Cephalaspis lloydii, Cephalaspis lyelli, Cephalaspis murchisoni, Cephalaspis novaescotiae, Cephalaspis oeselensis, Cephalaspis pagei, Cephalaspis podolica, Cephalaspis powriei, Cephalaspis rostratus, Cephalaspis scotica, Cephalaspis westolli, Cephalaspis whitei, Cephalaspis wyomingensis
Subtaxa: Cephalaspis (Cwmaspis) billcrofti
Type: Cephalaspis (Cwmaspis) billcrofti
Ecology: planktonic suspension feeder
Distribution: found only at Cwm Mill (Devonian of the United Kingdom)