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)
Colubridae (family)
Natricinae (subfamily)
Thamnophis (genus)
Thamnophis proximus (species)
[hide inferior taxa]