root › cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Chondrichthyes › Elasmobranchii › Selachii › Squalomorphii › Squaliformes › Somniosidae › Somniosus