Figure 1.A Sternaspis sp. ventral view with some morphological features B Ventro-caudal shields of some Sternaspis species C Shield parts as herein proposed to distinguish different species (AD: anterior depression, FPP: fan posterior projection) (A modif. after Uschakov 1955, reproduced with permission; B–C modified after von Marenzeller 1890).
Figure 9.Sternaspis fossor Stimpson, 1853 A Juvenile (HMCS 9953670), anterior end exposed, ventral view B Another specimen (HMCS 9953671), ventro-caudal shield, frontal view C Neotype (USNM 15543), anterior end exposed, ventral view D Same, ventro-caudal shield, frontal view E–F Ventro-caudal shields of three other specimens (USNM 7872). Bars: A, F 1 mm B 0.6 mm C, E 0.8 mm D 0.7 mm G 1.2 mm.