the root (no rank)
Eukaryota (domain)
Metazoa (kingdom)
Chordata (phylum)
Craniata (subphylum)
Vertebrata (no rank)
Gnathostomata (superclass)
Sarcopterygii (class)
Tetrapoda (no rank)
Amniota (no rank)
Sauropsida (no rank)
Sauria (no rank)
Lepidosauria (superorder)
Squamata (order)
Serpentes (suborder)
Colubroidea (superfamily)
Viperidae (family)
Crotalinae (subfamily)
Agkistrodon (genus)
Agkistrodon contortrix (species)
Agkistrodon contortrix mokasen (subspecies)
[hide inferior taxa]