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

Abstract

reconstructions (e.g. Pemberton 1992, Pemberton et al. 2001, Buatois & Mángano 2011, Knaust & Bromley 2012) and for detecting evolutionary trends (e.g. Mángano & Buatois 2016a, b). Increased interest in ichnology resulted in the description and erection of numerous ichnotaxa that allowed for their recurrent recognition and communication. However, after the compilation of the second edition of the Trace Fossils volume in the Treatise of Invertebrate Paleontology (Häntzschel 1975), the number of valid invertebrate ichnogenera has multiplied (Knaust 2012, Buatois et al. 2017). Many ichnotaxa are based on weak grounds, either due to in­ appropriate characteristics chosen as ichnotaxobases, poor preservation, single specimens, or simply overlooked synonymy. Accordingly, comprehensive ichnotaxonomic reciews are necessary for the efficient and robust applic a­ tion of ichnologic evidence. This contribution provides a taxonomic assessment of the ichnospecies Curvolithus gregarius Fritsch, 1908 from the Upper Ordovician of Czechia (see Mikuláš 1992, for previous evaluations of this ichnofauna), based on a reinvestigation of the type material and newly col­ lected specimens. In a general review of the ichnogenus Curvolithus, Buatois et al. (1998) excluded the ichno­ species C. gregarius from that ichnogenus due to the morphological discrepancy with the diagnostic features of Curvolithus. These authors also noted similarities of the type material of C. gregarius with other scratched trace fossils supposedly produced by arthropods, such as Tam bia and Monomorphichnus. However, no formal ichno taxo ­ n omic decision was made at that time, and the ichno­ taxon omic status of this ichno species was left indeterminate. Here, we formally include C. gregarius in Tambia Müller, 1969 as T. gregaria comb. nov. In addition, we briefly revise other ichnotaxa described by Fritsch (1908) that are related to T. gregaria. This study is part of an overall examination of historical trace­fossil collections and ichnotaxonomic re­evaluation of the collection of Fritsch (1908) at the National Museum in Prague, Czechia.