''Agkistrodon contortrix mokasen'' (or northern copperhead) was formerly a

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

found in the eastern

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. However, recent taxonomic changes do not recognize the northern copperhead (''A. c. mokasen'') as a valid taxon.

New taxonomy

The northern copperhead (''Agkistrodon contortrix mokasen'') was once classified as a subspecies of the copperhead (''Agkistrodon contortrix''). However,

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

based studies published in 2008 and 2015, revealed no significant genetic difference between the northern copperhead (''Agkistrodon contortrix mokasen''), the southern copperhead (''Agkistrodon contortrix contortrix'') and the Osage copperhead (''Agkistrodon contortrix phaeogaster''). The three subspecies were synonymized and elevated to one species, with the oldest published name, ''Agkistrodon contortrix'', having priority. The resulting taxonomy does not recognize the northern copperhead (''Agkistrodon contortrix mokasen'') as a valid taxon.Guiher TJ, Burbrink FT (2008). ''Demographic and phylogeographic histories of two venomous North American snakes of the genus Agkistrodon.'' Molecular Phylogenetics and Evolution, 48: 543–553.Burbrink, Frank T. and Timothy J. Guiher. 2014. ''Considering gene flow when using coalescent methods to delimit lineages of North American pitvipers of the genus Agkistrodon.'
Zoological Journal of the Linnean Society, 173: 505–526
Several subsequent reviews and species accounts have followed and supported the revised taxonomy.Crother, B. I. (editor). 2017. ''Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding, 8th. edition.'' SSAR Herpetological Circular 43, 1–102 pp. (page 59) Powell, Robert, Roger Conant, and Joseph T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, 4th ed. Houghton Mifflin Harcourt Publishing Co. New York. 494 pp. Uetz P, Freed P, Aguilar R, Hošek J (editors) (2021). The Reptile Database
Agkistrodon contortrix
(accessed 30 August 2021)

Description

The northern copperhead grows to a typical length of , with a maximum of .Conant R. 1975. ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition''. First published in 1958. Houghton Mifflin Company Boston. 429 pp. 48 plates. . (pbk.). The

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

are weakly keeled. The anal plate is single. The

subcaudals In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Comstock Publishing Associates, a Division of Cornell University Press. (7t ...

are single, at least anteriorly. The color pattern consists of an hourglass pattern that runs the length of the body. From above, a series of dark chestnut crossbands looks narrow in the center and wider on the sides. Between the crossbands, small, dark spots are often present. Dark, rounded spots occur at the sides of the belly. The head is a copper-red color. Juvenile specimens are lighter in color, and have a yellow tail tip and a narrow dark line that runs through the eye that divides the darker head from the lighter-colored

labial scales The labial scales are the scales of snakes and other scaled reptiles that border the mouth opening. These do not include the median scales on the upper and lower jawsWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates (7 ...

Common names

Northern copperhead, Gloyd HK, Conant R. 1990. ''Snakes of the Agkistrodon Complex: A Monographic Review''. Society for the Study of Amphibians and Reptiles. 614 pp. 52 plates. LCCN 89-50342. . copperhead, resident copperhead, highland moccasin, Wright AH, Wright AA. 1957. ''Handbook of Snakes of the United States and Canada''. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. . beech-leaf snake, chunk head, copper (adder), copper-bell, copper belly, copperhead moccasin, copperhead viper, copper snake, copper viper, deaf adder, deaf snake, harlequin snake, hazel head, North American copperhead snake, northern copperhead, pilot, poplar leaf, rattlesnake pilot, rattlesnake's mate, red adder, red eye, red snake, red viper, thunder snake, upland moccasin, white oak snake, adder.

Geographic range

This subspecies is found in the

Washington D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...

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East Texas East Texas is a broadly defined cultural, geographic, and ecological region in the eastern part of the U.S. state of Texas that consists of approximately 38 counties. It is roughly divided into Northeast Texas, Northeast, Southeast Texas, Sout ...

, southern

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, southern

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, throughout

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

, northern

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

, northern

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

, northeast to

Massachusetts Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...

(which considers the
endangered
,

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

Hudson Valley region, the Appalachian Mountain region and associated plateaus, and southwestern

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. No type locality was given.

Behavior

These snakes are generally quiet, almost lethargic, preferring to lie motionless or to make a slow retreat when encountered. When sufficiently agitated, however, they can strike vigorously and may vibrate their tails rapidly.

References

External links

* {{Taxonbar, from=Q4692718 contortrix mokasen Reptiles of the United States