So far I have only found one specimen of Squatinella leydigi in February 2017 in a sample from the Simmelried. Unfortunately, I mistook the specimen for the similar species Squatinella longispinata, which is why I only took photos from the dorsal view (s. fig. 1 a-d).
Although the specimen is only visible from the dorsal side, it can be identified as Squatinella leydigi, because the head shield is shaped like a mushroom cap. The two lateral auricles can also be seen in the blur (s. fig. 1 d). Another characteristic feature of Squatinella leydigi is the blunt end of the dorsal spine (s. fig. 2).
Fig. 1 a-d:Squatinella leydigi. L = 137 µm. Different focal planes from dorsal. Note the mushroom cap-shaped head shield (HS). The two lateral auricles (AU) are out of focal plane. DS = dorsal spine, FT = foot, TO = toes. Obj. 60 X.
Fig. 2:Squatinella leydigi. The blunt distal end of the dorsal spine (arrow). Obj. 60 X.