Two new Palaeocene osteoglossomorphs from Canada, with a reassessment of the relationships of the genus †Joffrichthys, and analysis of diversity from articulated versus microfossil material

A single block containing five articulated osteoglossomorphs was recovered from the Paskapoo Formation of southern Alberta, during development of a residential community in Calgary. Two of the specimens represent a new species of dagger Joffrichthys, and the other three represent a new genus and species of osteoglossomorph. The discovery of a new species of dagger Joffrichthys led us to re-examine the type species and to recode many of the characters that have been used in phylogenetic analyses. In particular, we interpret the caudal skeleton of dagger Joffrichthys to have 16 branched principal rays, not 15, which indicates this genus does not belong in Osteoglossiformes, and removes it from the osteoglossid/heterotidine affiliations previously reported. We assessed the relationships of the two new taxa using a modified data matrix including new outgroups and corrected data, with and without the inclusion of dagger Ostariostoma. Our results show that dagger Joffrichthys is a basal member of the superorder, and not a member of the Heterotidinae, but the other new taxon is left incertae sedis in the superorder. We also provide data on the early history of osteoglossomorphs in North America provided by isolated elements from Cretaceous and Palaeocene microfossil sites that complement and supplement that provided by articulated specimens.