Arthropod Trace Fossils of the Upper Lower Cambrian Gog Group, Southern Rocky Mountains of Canada

The upper lower Cambrian Gog Group in the southern Rocky Mountains of Canada displays a high diversity and abundance of arthropod traces. Four ichnogenera, Cruziana, Diplichnites, Monomorphichnus, Rusophycus, and “Indeterminate Arthropod Scratches” are discussed, with a total of 17 different ichnospecies, as follows: Cruziana billingsi (Fillion and Pickerill, 1990), Cruziana irregularis (Fenton and Fenton, 1937), Cruziana jenningsi (Fenton and Fenton, 1937), Cruziana navicella (Fenton and Fenton, 1937), Cruziana omanica (Seilacher, 1970), Cruziana pectinata (Seilacher, 1994), Cruziana penicillata (Gibb, Chatterton, and Pemberton, 2009), Cruziana plicata (Crimes, Legg, Marcos, and Arboleya, 1977), Cruziana tenella (Linnarsson, 1871), Diplichnites twelvetreesi (Chapman, 1928), Monomorphichnus bilinearis (Crimes, 1970b), Monomorphichnus lineatus (Crimes, Legg, Marcos, and Arboleya, 1977), Rusophycus eutendorfensis (Linck, 1942), and Rusophycus unilobus (Seilacher, 1970). Three new ichnospecies, i.e., Cruziana caputinclinata isp. nov., Rusophycus subnotous isp. nov., and Diplichnites obliquus isp. nov., are proposed, described, and illustrated. The ichnofauna collected from three localities (Lake O'Hara, Mount Babel, and Redoubt Mountain) are predominantly Cruziana. Evidence of nutrient-rich substrates containing microbially induced sedimentary structures and the ichnospecies present confirm that the trace fossil bearing strata are part of the Cruziana ichnofacies and were deposited in a fully marine basin between fair weather wave base and storm wave base.