Fig. 3

Schematic drawings of the musculature of Diuronotus aspetos. Anterior end is pointing at the top for a and b, dorsal side is pointing at the top for c–h. a Ventral view of the musculature, b dorsal view of the musculature, c–h cross section of the specimen, c in the head, d posterior part of the pharynx, e anterior of the trunk, f posterior of the trunk, g post-anal region of the trunk, h and in the furca before bifurcation of the tubes. Note that in c and d, the helicoidal pharyngeal musculature is represented in dash lines due to the uncertainty of its presence, and it is not drawn in (a and b). aps anterior pharyngeal sphincter, cmag circular muscle of the adhesive gland, dlm dorsal longitudinal muscle, dvlm dorsal projection of the ventral longitudinal muscle, dvm dorso-ventral muscle, hdm head diagonal muscle, hm helicoidal muscle, int intestine, lplm lateral pharyngeal longitudinal muscle, lvlm Lateral extension of the ventral longitudinal muscle, mvlm medial projection of the ventral longitudinal muscle, ov ovary, pcm pharyngeal circular muscle, pdm posterior diagonal muscle, pddm pharyngeal dorsal diagonal muscle, pdlm pharyngeal dorsal longitudinal muscle; pps posterior pharyngeal sphincter, rpm radial pharyngeal muscles, scm semi-circular muscle, tdm tube diagonal muscle, vllm ventro lateral longitudinal muscle, vlm ventral longitudinal muscle