A large, new dercetid fish (Teleostei: Aulopiformes) from the Campanian Bearpaw Formation of Alberta, Canada

Abstract

Two new fossil fish specimens were recovered from deposits of the Bearpaw Formation of southern Alberta, Canada. These deposits represent the Western Interior Seaway in the Campanian. The remains can be confidently assigned to the aulopiform genus Dercetis in the extinct family Dercetidae. The two specimens are here described as Dercetis magnificus sp. nov. Based on a phylogenetic analysis, this new species is placed as the sister-group to the only other valid species of the genus, D. elongatus and D. triqueter. The genus Dercetis was previously documented from the western area of the Tethys and the Western Interior Seaway by only a small individual from Mexico and an incomplete braincase from Alberta, Canada, neither of which was assigned to a particular species. The new species is represented by specimens that are larger than the any other previously reported Dercetis, documenting the potential to attain a very large body size in the genus Dercetis and Dercetidae.