Parathyonidium

Heding & Panning, 1954

1 species

Small dendrichirotid holothurians with 15 tentacles and with one simple basal plan. But the calcareous ring was largely reformed. No interradialia and no dendroform gills. In the epidermis there are thorny perforated plates. The calcareous rng must be described as simple because of the missing forked tail. This identifies it as a member of the Thyonidiinae. (Heding & Panning, 1954)