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)
[hide inferior taxa]
Thamnophis atratus (species)
Thamnophis couchii (species)
Thamnophis cyrtopsis (species)
Thamnophis elegans (species)
Thamnophis errans (species)
Thamnophis nigronuchalis (species)
Thamnophis ordinoides (species)
Thamnophis proximus (species)
Thamnophis radix (species)
Thamnophis sirtalis (species)