The Notacanthiformes is an ancient group of deep-sea ray-finned fishes comprising 27 species in two families; Halosauridae and Notacanthidae. Although many studies have tried to reconstruct the phylogenetic relationships among the major clades of Elopomorpha,

As part of an ongoing effort to monitor the fish diversity in Greenland waters using morphological and molecular taxonomy, and construct pragmatic identification keys, we here update distributions of all known halosaurs (Halosauridae) and notacanthids

From 2009 to 2011 thirty-five specimens belonging to six halosaurid species of the family Halosauridae were captured in two different locations in the northern waters of Spain. The specimens were identified as belonging to the genera Halosauropsis Collett,