Spongeliomorpha in nonmarine settings: an ichnotaxonomic approach

Abstract

ABSTRACTThe authors revise the occurrences of burrow networks with striated walls having dominantly transverse to oblique striae, which have been assigned to the ichnogeneraSpongeliomorphaSaporta, 1887, andSteinichnusBromley & Asgaard, 1979. The taxonomic status of the ichnogenusSteinichnusBromley & Asgaard, 1979 is examined and it is suggested that this ichnogenus is a subjective junior synonym ofSpongeliomorphaSaporta, 1887.Spongeliomorphais best reserved for an unlined network of burrows having distinct surface ridges or grooves of different orientation and massive filling. The diagnosis ofSpongeliomorphais emended accordingly and the proposed ichnospecies revised for consistency with the diagnostic features of the ichnogenus.Spongeliomorpha milfordensisMetz, 1993a is considered a subjective junior synonym ofSpongeliomorpha carlsbergi(Bromley & Asgaard, 1979) after a visual comparison and statistical analysis of the angle of striation with respect to the burrow midline in the type material. Nevertheless, the use of statistical techniques is not advocated for distinction of ichnotaxa, but may support observations.Spongeliomorpha carlsbergiis considered as an indicator of nonmarine settings and was probably produced by burrowing insects. Proposed ichnospecies ofSpongeliomorphathat fit the emended diagnosis includeS. sudolica(Zaręczny, 1878);S. ibericaSaporta, 1887;S. siculaD’Alessandro & Bromley, 1995;S. chevronensisMuñiz & Mayoral, 2001; andSpongeliomorphaisp. nov. aff.siculaLewy & Goldring, 2006.