A high latitude euselachian assemblage from the early Turonian of Alberta, Canada

Numerous isolated euselachian teeth were recovered from the early Turonian Kaskapau Formation situated in northwestern Alberta, Canada. This high palaeolatitude assemblage was collected from a sandstone lens along the bank of the Smoky River, and includes 16 species belonging to at least three orders, at least 11 families, and 15 genera. Here we describe Odontaspis watinensis sp. nov. and report the first Canadian occurrence of Polyacrodus sp., Scapanorhynchus sp., and Carcharias aff. C. striatula. The scarcity of benthic taxa in this assemblage supports the previous notion that bottom waters in this region of the Western Interior Seaway experienced enduring anoxic episodes. By comparing the faunal composition of this assemblage with that of middle Cenomanian Canadian assemblages, we show that seven species have a biostratigraphical range that extended across the Cenomanian-Turonian boundary in the northern region of the seaway. Of the taxa described herein, Archaeolamna ex. gr. kopingensis, Cardabiodon aff. C. ricki, Carcharias aff. C. striatula, Odontaspis watinensis, and Johnlongia parvidens have not been reported from deposits of the southernmost region of the seaway and may have been restricted to cooler waters.