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 halys (species)
Agkistrodon halys brevicaudus (subspecies)
[show inferior taxa]