the root (no rank)
Eukaryota (domain)
Metazoa (kingdom)
Chordata (phylum)
Craniata (subphylum)
Vertebrata (no rank)
Petromyzontiformes (order)
Petromyzontidae (family)
Ichthyomyzon (genus)
[hide inferior taxa]
Ichthyomyzon fossor (species)
Ichthyomyzon unicuspis (species)