Rosselia Dahmer, 1937

Ichnotaxonomy: R. socialis is the most common ichnospecies of the ichnogenus Rosselia and probably the only valid one.

Diagnosis: Irregularly bulbous to conical or funnel-shaped structures predominantly vertical, comprising a central shaft surrounded either by a concentrically layered wall or by helicoid swirls of spreitelike, closely appressed small burrow fills.

Diagnosis Conical to irregularly bulbous or funnel - shaped structures, vertical to horizontal, consisting either of a small central burrow surrounded by broad, concentric, cone-in-cone laminae, or of spreitelike helicoid swirls surrounding a cone, both tapering downward to a concentrically walled, subcylindrical stem.