The ichnospecies Tambia gregaria (Fritsch, 1908) comb. nov. from the Upper Ordovician of Czechia

The trace fossil Curvolithus gregarius Fritsch, 1908 was introduced for curved and scratched burrows at the base of sandstone beds formed in storm-dominated environments recorded in the Upper Ordovician Kosov Formation in Czechia. Given its morphological difference with Curvolithus multiplex Fritsch, 1908, the type ichnospecies of Curvolithus, C. gregarius is transferred to the ichnogenus Tambia Müller, 1969 as Tambia gregaria comb. nov. This crescent-shaped burrow contains sets of robust, rarely overlapping scratches, suggesting an arthropod producer. It is commonly closely associated with elongate cylindrical burrows, which partly have an active backfill. Potential behavioural interpretations are discussed, but the available evidence is still insufficient.