A primitive clupeomorph from the Albian Loon River Formation (Northwest Territories, Canada)

Abstract

Foreyclupea loonensis, gen. et sp. nov., is described from the early–middle Albian Loon River Formation of the Northwest Territories, Canada. The only specimen of the new species was originally described as a part of an enigmatic taxon Erichalcis arcta in 1975, which was assigned to the Clupeomorpha. Since then, E. arcta has proven to be a composite taxon, made up of clupeomorph and non-clupeomorph specimens. The non-clupeomorph material was redescribed as a Euteleostei incertae sedis and retained the species name. Described herein is the fossil clupeomorph specimen originally assigned to Erichalcis arcta. As in other members of the superorder Clupeomorpha, the ventral margin of the body in the specimen is covered with spiny scutes, and the supratemporal commissural sensory canal passes through the parietals. Along with these diagnostic characters, the new taxon also shows primitive traits of the basal members of the group, including a medioparietal skull roof, unfused halves of the neural spines of the abdominal vertebrae, and no evidence of presence of the recessus lateralis. When included in a phylogenetic analysis of the Early Cretaceous clupeomorphs, the new species forms a clade with the Early Cretaceous clupeomorphs from Mexico and Brazil, Ranulfoichthys dorsonudum and Scutatuspinosus itapagipensis, respectively.