Diagnosis: Short and wide Trypanites having a cylindrical or slightly curved form, emplaced within but never completely penetrating a subspherical bioclast (calcareous sponge or psychocidarid echinoid radiole).

Differential diagnosis: T. mobilis isp. n. is distinguished from all other Trypanites ichnospecies by its diagnostic and exclusive occurrence in mobile sub-spherical bioclasts. The type ichnospecies T. weisei Mägdefrau, 1932 is mostly smaller in size and more slender. T. fimbriatus (Stephenson, 1952) is similar to the present traces except for its hardground occurrence and a slightly club-shaped morphology. In contrast to all other Trypanites ichnospecies T. solitarius (Hagenow, 1840) is oriented (sub-)horizontally in respect to the substrate surface and may show sinuosity. Like T. weisei, T. fosteryeomani Cole and Palmer, 1999 is more slender.