Taxonomic History
The genus Agkistrodon has long been placed into the pit viper family, with other snakes such as rattlesnakes. There has been much debate as to whether this group should be a family of its own or a subfamily within the family Viperidae (Gloyd and Conant 1990). They are now considered a subfamily, Crotalinae, under the family Viperidae (Gloyd and Conant 1990).

Since its discovery in the late 18th century, the northern copperhead has been given many different names. Here is a complete history (from Conant, 1990) of the nomenclature of Agkistrodon contortrix mokasen:

Agkistrodon mokasen by Palisot de Beauvois in 1799
Cenchris mokeson by Daudin in 1803
Scytalus cupreus by Rafinesque in 1818
Scytale cupreus by Say in 1819
Scytale mockeson by Say in 1819
Tisiphone cuprea by Fitzinger in 1826
Cenchris marmorata by F. Boie in 1827.
Acintias atrofuscus by Troost in 1836
Toxicophis atrofuscus by Troost in 1836
Trigonocephalus cechris by Schlegel 1837
Trigonocephalus contortix by Holbrook in 1838
Trigonocephalus atrofuscus by Holbrook in 1842
Cenchris contortix by Gray in 1842
Cenchris atrofuscus by Gray in 1849
Trigonocephalus histrionicus by Dumeril in 1853
Agkistrodon contortix by Baird and Girard in 1853
Ancistrodon contortix by Baird in 1854
Agkistrodon contorting by Abbott in 1869
Ancistrodon atrofuscus by Cope in 1875
Ancistrodon contortix by S. Garman in 1883
Ancistrodon mokasen by Brown in 1908
Agkistrodon mokasen mokasen by Gloyd and Conant in 1934
Agkistrodon mokasen cupreus by Glod and Conant in 1938
Agkistrodon mokeson mokeson by Gloyd and Conant in 1943
Agkistrodon mokeson by Davis and Brimley in 1944
Agkistrodon contortix mokeson by Klauber in 1948
Ancistrodon contortrix mokeson by Schmidt in 1953
Ancistrodon contortix contortrix by Prince, Duppstadt, and Lyons in 1955
Agkistrodon contortrix mokasen by Smith and Gloyd in 1964 (This is the currently accepted nomenclature.)
Ancistrodon contortix mokasen by Peterson in 1970


Type Locality:
The type locality of this species is the area around Philadelphia, Pennsylvania.

Agkistrodon is only one of several genera in the subfamily; however, it does include many snakes in both the Old and New World. Among them is the Copperhead, Agkistrodon contortrix. Within this species, several subspecies exist. They include: A. c. contortix, the Southern Copperhead, A. c. laticinctus, the Broad Banded Copperhead, A. c. mokasen, the Northern Copperhead, A. c. phaeogaster, the Osage Copperhead, and A. c. pictigaster, the Transpecos Copperhead.

Other genuses in the subfamily Crotalinae include, but are not limited to, Bothriechis, the eyelash vipers, Crotalus, the rattlesnakes, Sistrurus, the massasauga and pygmy rattlesnakes, and Trimeresurus, tropical pit vipers and other tree vipers.