The Center for North American Herpetology

THE CENTER FOR NORTH AMERICAN HERPETOLOGY

SOCIETY FOR THE STUDY OF AMPHIBIANS AND REPTILES

Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding, 9th Edition

STANDARD ENGLISH NAMES FOR NORTH AMERICAN AMPHIBIANS AND REPTILES COMMITTEE

Committee Chairperson/Editor:

Kirsten E. Nicholson, (Department of Biology, Central Michigan University)

Taxonomic Subcommittees:

(view subcommittees and members)

Class:

Order:

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Genus:

Origin:

Your search returned 174 species; denotes an update since the 9th edition (2025)

Reptilia Laurenti, 1768 — Reptiles

Squamata (part) Oppel, 1811 — Snakes

Boidae Gray, 1842 — Boas

Charina Gray, 1849 — Rubber Boas

C. bottae (Blainville, 1835) — Rubber Boa

The subspecific inclusion of C. b. umbratica necessitated the change in English name from "Northern Rubber Boa".

C. b. bottae (Blainville, 1835) — Northern Rubber Boa

C. b. umbratica Klauber, 1943 — Southern Rubber Boa

Based on morphological data from hundreds of additional specimens, Hoyer et al. (2019, The Southwestern Naturalist 64: 23–30) expanded the geographical distribution of C. umbratica, which was corroborated by Grismer et al. (2022, Molecular Phylogenetics and Evolution 174(107542): 1–17) using a genome-wide SNP dataset. Grismer et al. (op. cit.) found that C. umbratica was morphologically distinct from C. bottae, but recognizing umbratica as a species would make bottae paraphyletic. Additionally, they found that C. umbratica was composed of several distinct lineages occurring in sky islands across southern California. The authors recognized umbratica at least as a subspecies in the interest of having it as a recognized taxon, listed under the Federal Endangered Species Act.

Lichanura Cope, 1861 — Rosy Boas

Wood and Holycross (In Holycross and Mitchell, 2020, Snakes of Arizona. ECO Publishing: 80–81) cite a reanalysis of data first used by Wood et al. (2008, Molecular Phylogenetics. and Evolution. 46: 484–582) in which geographic boundaries are shifted between clades in northern Baja California such that the name L. orcutti would be replaced with L. roseofusca. However, the analysis remains unpublished.

	*L. orcutti* Stejneger, 1889 — Northern Rosy Boa “Northern” was added to the English name to differentiate it from the English name of the genus. The taxonomic authority was corrected by removing the parentheses.
	*L. trivirgata* Cope, 1861 — Three-lined Boa The authority was corrected, and the parentheses were removed.

Colubridae Oppel, 1811 — Harmless Egg-laying Snakes

Arizona Kennicott, in Baird, 1859 — Glossy Snakes

Using genetic data, Myers et al. (2017, Journal of Biogeography 44: 461–474; Myers et al., 2019, Molecular Ecology 28: 4535-4548) and Dahn et al. (2018, Molecular Phylogenetics and Evolution 129: 214–225) confirmed that the eastern and western populations were distinct as predicted by Collins (1991, Herpetological Review 22: 42–43). However, neither study recommended taxonomic changes.

A. elegans Kennicott, in Baird, 1859 — Glossy Snake

	*A. e. arenicola* Dixon, 1960 — Texas Glossy Snake
	*A. e. candida* Klauber, 1946 — Mohave Glossy Snake
	*A. e. eburnata* Klauber, 1946 — Desert Glossy Snake
	*A. e. elegans* Kennicott, in Baird, 1859 — Kansas Glossy Snake
	*A. e. noctivaga* Klauber, 1946 — Arizona Glossy Snake
	*A. e. occidentalis* Blanchard, 1924 — California Glossy Snake
	*A. e. philipi* Klauber, 1946 — Painted Desert Glossy Snake

Bogertophis Dowling and Price, 1988 — Desert Ratsnakes

B. rosaliae (Mocquard, 1899) — Baja California Ratsnake

B. subocularis (Brown, 1901) — Trans-Pecos Ratsnake

B. s. subocularis (Brown, 1901) — Northern Trans-Pecos Ratsnake

Cemophora Cope, 1860 — Scarletsnakes

C. coccinea (Blumenbach, 1788) — Common Scarletsnake

“Common” was added to the English name to differentiate it from the English name of the genus.

	*C. c. coccinea* (Blumenbach, 1788) — Florida Scarletsnake
	*C. c. copei* Jan, 1863 — Northern Scarletsnake

C. lineri Williams, Brown, and Wilson, 1966 — Texas Scarletsnake

Coluber Linnaeus, 1758 — North American Racers

Myers et al. (2017, Copeia 2017: 642–650), using combined mtDNA and nDNA data, demonstrated that C. constrictor and Masticophis spp. were sister taxa. Therefore, we recognize Masticophis as a genus. The standard English name was changed to reflect this. Myers et al (2024, Zoological Journal of the Linnean Society, zlae018) did not find strong support for some of these subspecies but further research is required to clarify subspecies delineations.

C. constrictor Linnaeus, 1758 — North American Racer

	*C. c. anthicus* (Cope, 1862) — Buttermilk Racer
	*C. c. constrictor* Linnaeus, 1758 — Northern Black Racer
	*C. c. etheridgei* Wilson, 1970 — Tan Racer
	*C. c. flaviventris* Say in James, 1822 — Eastern Yellow-bellied Racer The date of publication is corrected to 1822 based on Woodman (2010, Archives of Natural History 37: 28–38).
	*C. c. foxii* (Baird and Girard, 1853) — Blue Racer
	*C. c. helvigularis* Auffenberg, 1955 — Brown-chinned Racer
	*C. c. latrunculus* Wilson, 1970 — Black-masked Racer
	*C. c. mormon* Baird and Girard, 1852 — Western Yellow-bellied Racer
	*C. c. oaxaca* (Jan, 1863) — Mexican Racer
	*C. c. paludicola* Auffenberg and Babbitt, 1953 — Everglades Racer
	*C. c. priapus* Dunn and Wood, 1939 — Southern Black Racer

Drymarchon Fitzinger, 1843 — Indigo Snakes

D. couperi (Holbrook, 1842) — Eastern Indigo Snake

Krysko et al. (2016, Zootaxa 4138: 549–569) described a new taxon, D. kolpobasileus, based on morphological differences of the skull and mtDNA sequence data from D. couperi. Guyer et al. (2019, Zootaxa 4695: 168–174) were unable to confirm head-shape differences between D. kolpobasileus and D. couperi, and Folt et al. (2019, PLoS One 14: e0214439) examined lineage structure using nDNA and found it failed to support conclusions from mtDNA alone. Both the Guyer and Folt studies recommend against recognition of D. kolpobasileus.

D. melanurus (Duméril, Bibron, and Duméril, 1854) — Central American Indigo Snake

D. m. erebennus (Cope, 1860) — Texas Indigo Snake

Drymobius Fitzinger, 1843 — Neotropical Racers

D. margaritiferus (Schlegel, 1837) — Speckled Racer

D. m. margaritiferus (Schlegel, 1837) — Northern Speckled Racer

Ficimia Gray, 1849 — Eastern Hook-nosed Snakes

F. streckeri Taylor, 1931 — Tamaulipan Hook-nosed Snake

Gyalopion Cope, 1860 — Western Hook-nosed Snakes

The date of publication was corrected to 1860 (see Nolan, 1913, Index to the Scientific Contents of the Journal and Proceedings of the Academy of Natural Sciences of Philadelphia:xii).

	*G. canum* Cope, 1860 — Chihuahuan Hook-nosed Snake The date of publication was corrected to 1860 (see Nolan, 1913, Index to the Scientific Contents of the Journal and Proceedings of the Academy of Natural Sciences of Philadelphia: xii).
	*G. quadrangulare* (Günther, 1893 in Salvin and Godman, 1885-1902) — Thornscrub Hook-nosed Snake

Lampropeltis Fitzinger, 1843 — Kingsnakes

	*L. alterna* (Brown, 1901) — Gray-banded Kingsnake Based on morphology and color pattern, Hansen and Salmon (2017, Mesoamerican Herpetology 4: 699–758) assign all U.S. populations to a monotypic L. alterna. Using genome-scale data, Myers et al. (2019, Molecular Phylogenetics and Evolution 131(2019): 211–218) reported three lineages within L. alterna, again with only L. alterna occurring in the U.S.
	*L. annulata* Kennicott in Cope, 1860 — Mexican Milksnake The publication date was corrected to 1860 (see Nolan, 1913, Index to the Scientific Contents of the Journal and Proceedings of the Academy of Natural Sciences of Philadelphia: xii). This species comprises a Mexican lineage of the former L. triangulum and is of uncertain occurrence in the United States. The morphotype of L. annulata occurs throughout southern Texas, but the identity of those populations was not evaluated by Ruane et al. (2014, Systematic Biology 63: 231–250). Until further detailed evaluation, we retain L. annulata as a species that likely occurs in southern Texas that may hybridize with L. gentilis or may ultimately prove to be part of L. gentilis, as suggested by the limited sampling in Burbrink et al. (2021, Systematic Biology 71: 839–858). See Chambers and Hillis (2020, Systematic Biology 69: 184–193) for alternate views on the validity of this species as distinct from the former L. triangulum (see additional comments under L. gentilis and L. triangulum).
	*L. californiae* (Blainville, 1835) — California Kingsnake See comments under L. getula.
	*L. calligaster* (Harlan, 1827) — Prairie Kingsnake
	*L. elapsoides* (Holbrook, 1838) — Scarlet Kingsnake The recognition of L. elapsoides as a species was confirmed in a large multilocus study with many individuals sampled by Ruane et al. (2014, Systematic Biology 63: 231–250) and further evaluated and supported with genomic analyses in Burbrink et al. (2021, Systematic Biology 71: 839–858); see additional comments under L. triangulum).
	*L. extenuata* (Brown, 1890) — Short-tailed Kingsnake
	*L. floridana* Blanchard, 1919 — Florida Kingsnake
	*L. gentilis* (Baird and Girard, 1853) — Western Milksnake A multilocus molecular study by Ruane et al. (2014, Systematic Biology 63: 231–250) indicated that L. gentilis is distinct from the former L. triangulum; additional sampling of L. gentilis with detailed examination of gene-flow, in conjunction with ecological niche-modeling analyses by Burbrink et al. (2022, Systematic Biology 71: 839–858), found that L. gentilis hybridizes with L. triangulum and that this occurs primarily where the eastern Nearctic forests transition to the grasslands of the Great Plains but otherwise remains distinct throughout its range. See Chambers and Hillis (2020, Systematic Biology 69: 184–193) and Chambers et al. (2023, Systematic Biology 72: 357–371>) for alternate views on the validity of this species as distinct from the former L. triangulum and see additional comments under L. triangulum.
	*L. getula* (Linnaeus, 1766) — Eastern Kingsnake Using genome-scale data from 51 specimens across their range, Harrington and Burbrink (2022, Journal of Biogeography 50: 341–351) suggested the presence of three lineages in the L. getula complex: L. californiae, L. splendida, and all populations east of the Chihuahuan Desert/Great Plains interface. The paper did not make taxonomic conclusions, but rather determined biogeographic factors influencing lineage formations in a wide-ranging species complex. It is suggested that further sampling and genomic work are needed to determine if L. getula, L. nigra, and L. holbrooki should be collapsed into the single species L. getula.
	*L. holbrooki* Stejneger, 1902 — Speckled Kingsnake See comments under L. getula. The date of publication was corrected to 1860 (see Nolan, 1913, Index to the Scientific Contents of the Journal and Proceedings of the Academy of Natural Sciences of Philadelphia: xii).
	*L. knoblochi* (Taylor, 1940) — Madrean Mountain Kingsnake
	*L. meansi* Krysko and Judd, 2006 — Apalachicola Kingsnake
	*L. multifasciata* (Bocourt, 1886 in Duméril, Mocquard, and Bocourt, 1870-1909) — Coast Mountain Kingsnake
	*L. nigra* (Yarrow, 1882) — Eastern Black Kingsnake See comments under L. getula.
	*L. nigrita* Zweifel and Norris, 1955 — Western Black Kingsnake
	*L. occipitolineata* Price, 1987 — South Florida Mole Kingsnake
	*L. pyromelana* (Cope, 1867) — Arizona Mountain Kingsnake
	*L. rhombomaculata* (Holbrook, 1840) — Northern Mole Kingsnake
	*L. splendida* (Baird and Girard, 1853) — Desert Kingsnake See comments under L. getula.
	*L. triangulum* (Lacépède, 1789) — Eastern Milksnake As currently defined, L. triangulum comprises populations of the former subspecies L. t. triangulum, L. t. syspila (part), and L. t. amaura (part). Burbrink et al. (2022, Systematic Biology 71: 839–858) found using genome-scale data with detailed phylogeographic and hybrid-zone analyses, along with ecological niche-modeling analyses, that L. triangulum has a zone of hybridization (6% of the combined range) with L. gentilis that occurs primarily where the eastern Nearctic forests transition to the grasslands of the Great Plains but otherwise remains distinct throughout its range. This work also indicates that both L. triangulum and L. gentilis may hybridize with L. elapsoides specifically in a contact zone in Louisiana but that all three also remain distinct outside of that zone. In contrast, Chambers and Hillis (2020, Systematic Biology 69: 184–193) and Chambers et al. (2023, Systematic Biology 72: 357–371) argue that the hybridization detected between L. triangulum and L. gentilis renders these taxa as synonymous and thus all Nearctic milksnakes, excluding L. elapsoides, should be considered L. triangulum. However, Chambers et al. (op. cit.) also found the same two lineages corresponding to L. gentilis and L. triangulum, with the same area of connection as that inferred by Ruane et al. (2014, Systematic Biology 63: 231-250) and Burbrink et al. (2022, op. cit.).
	*L. zonata* (Lockington ex Blainville, 1876) — California Mountain Kingsnake

Masticophis Baird and Girard, 1853 — Whipsnakes

See comment under Coluber. O’Connell and Smith (2018, Molecular Phylogenetics and Evolution 127: 356–366, elevated ;M. piceus to species.

M. bilineatus Jan, 1867 — Sonoran Whipsnake

The date of publication has been corrected. The specific name bilineatum was introduced by Jan (1863, Elenco sistematico degli ofidi: vii + 143) as a nomen nudum, and was formally published by Jan (in Jan and Sordelli, 1867, Iconographie generale des ophidiens, volume 2, livraison 22, plate 6).

M. flagellum (Shaw, 1802) — Common Coachwhip

Using molecular and morphological data, O’Connell and Smith (2018, Molecular Phylogenetics and Evolution 127: 356–366), recognized populations west of the Cochise Filter Barrier as a distinct species, M. piceus. They recognized the named subspecies as evolutionary lineages within each species, though they did not evaluate the subspecies ruddocki. See also Myers et al. (2017, Molecular Phylogenetics and Evolution 127: 356–366) and Myers et al. (2019, Molecular Ecology 28: 1–14) also found division of these lineages occurring at the Cochise Filter Barrier using mtDNA and genome-scale data. The English name was modified to differentiate this species from the other species called “Coachwhips.”

	*M. f. flagellum* (Shaw, 1802) — Eastern Coachwhip
	*M. f. lineatulus* Smith, 1941 — Lined Coachwhip
	*M. f. testaceus* (Say in James, 1822) — Western Coachwhip

M. fuliginosus (Cope, 1895) — Baja California Coachwhip

O’Connell and Smith (2018, Molecular Phylogenetics and Evolution 127: 356–366) support recognizing M. fuliginosus as a species.

M. lateralis (Hallowell, 1853) — Striped Racer

	*M. l. euryxanthus* Riemer, 1954 — Alameda Striped Racer
	*M. l. lateralis* (Hallowell, 1853) — California Striped Racer

M. piceus (Cope, 1892) — Desert Coachwhip

See comments under M. flagellum. The epithet piceum was introduced by Cope (1875, Bulletin of the United States National Museum 1: 1–104) as a nomen nudum. It was formally proposed by Cope (1892, Proceedings of the United States National Museum 14: 589–694), in an issue dated "1891". Crombie (1994, Smithsonian Herpetological Information Service (101): 40), gives the date of Cope’s paper in which the formal description appeared as 28 March 1892. Using molecular and morphological data, O’Connell and Smith (2018, Molecular Phylogenetics and Evolution 127: 356–366 ), recognized populations west of the Cochise Filter Barrier as a distinct species, M. piceus. They recognized the named subspecies as evolutionary lineages within each species, though they did not evaluate the subspecies ruddocki. See also Myers et al. (2017, Molecular Phylogenetics and Evolution 127: 356–366) and Myers et al. (2019, Molecular Ecology : 1–14) also found the division of these lineages occurring at the Cochise Filter Barrier using mtDNA and genome-scale data. The English name was modified to differentiate this species from the other species called “Coachwhips.”

	*M. p. cingulum* (Lowe and Woodin, 1954) — Sonoran Coachwhip See comments under M flagellum.
	*M. p. piceus* (Cope, 1892) — Red Racer See comments under M flagellum.
	*M. p. ruddocki* Brattstrom and Warren, 1953 — San Joaquin Coachwhip See comments under M flagellum.

M. schotti Baird and Girard, 1853 — Schott's Whipsnake

	*M. s. ruthveni* Ortenburger, 1923 — Ruthven's Whipsnake
	*M. s. schotti* Baird and Girard, 1853 — Schott’s Striped Whipsnake

M. taeniatus (Hallowell, 1852) — Striped Whipsnake

	*M. t. girardi* (Stejneger and Barbour, 1917) — Central Texas Whipsnake
	*M. t. taeniatus* (Hallowell, 1852) — Desert Striped Whipsnake

Opheodrys Fitzinger, 1843 — Greensnakes

	*O. aestivus* (Linnaeus, 1766) — Northern Rough Greensnake Rittmeyer et al. (2021, Journal of Herpetology 55: 342–354) used multiple loci to detect three divergent lineages within O. aestivus. They elevate the sister lineage O. carinatus from subspecies to species based on its diagnosability from morphological and genetic data. Another lineage was detected from the Edwards Plateau of central Texas. Due to geographic gaps in sampling and undetermined morphological diagnosis, this clade was included within a broader concept of O. aestivus.
	*O. carinatus* Grobman, 1984 — Florida Rough Greensnake See comments under O. aestivus.
	*O. vernalis* (Harlan, 1827) — Smooth Greensnake

Oxybelis Wagler, 1830 — American Vinesnakes

Taxonomy follows Jadin et al. (2020, Organisms Diversity and Evolution 20: 723–746), who subdivided O. aeneus into six species based on genetic and morphological differences.

O. microphthalmus Barbour and Amaral, 1926 — Thornscrub Brown Vinesnake

See comments under Oxybelis.

Pantherophis Fitzinger, 1843 — North American Ratsnakes

Hillis and Wüster (2021, Herpetological Review 52: 51–52, substituted P. alleghaniensis for P. spiloides, and resurrected P. quadrivittatus).

	*P. alleghaniensis* (Holbrook, 1836) — Midland Ratsnake See comment under P. obsoletus.
	*P. bairdi* (Yarrow in Cope, 1880) — Baird's Ratsnake See comment under P. obsoletus.
	*P. emoryi* (Baird and Girard, 1853) — Great Plains Ratsnake See comment under P. guttatus.
	*P. guttatus* (Linnaeus, 1766) — Red Cornsnake Using genome-scale data, Myers et al. (2020, Molecular Ecology 29: 797–811) found support for three previously recognized species: P. guttatus, P. slowinskii, and P. emoryi. Subsequently, Marshall et al. (2021, Molecular Phylogenetics and Evolution 162: 1–12) demonstrated support for the same three taxa but also found P. emoryi could further be divided into the subspecies P. e. meahllmorum and P. e. emoryi, and also suggested that P. slowinskii be considered a subspecies of P. emoryi. We note that these subspecies of P. emoryi are all distinct evolutionary lineages, and relegating them to the category subspecies is arbitrary. When subspecies are found to be distinct lineages they are no different from the rank of species (see Burbrink et al., 2022,. Ecology and Evolution 12: 1–17).
	*P. obsoletus* (Say in James, 1822) — Western Ratsnake The date of publication is corrected to 1822 based on Neal (2010, Archives of Natural History 37: 28–38). Using genome-scale data, Burbrink et al. (2020, Evolution 75: 260–277) demonstrated support for continued recognition of P. obsoletus and P. bairdi as a sister species, but that the geographic range of P. spiloides extended further east and therefore overlapped with the locality of the type specimen of P. alleghaniensis at the summit of the Blue Ridge in Virginia (see Hillis and Wüster, 2021, Herpetological Review 52: 51–52 and Burbrink et al., 2021, Herpetological Review 53: 537–547). Thus, the former P. spiloides becomes P. alleghaniensis. The former P. alleghaniensis was then found to occupy the range of the former subspecies P. o. quadrivittatus, along the Southeastern Coast and Florida and thus becomes P. quadrivittatus. Suggestions that the ratsnakes P. obsoletus, P. alleghaniensis, and P. quadrivittatus should be considered subspecies of P. obsoletus (Hillis and Wüster, 2021, op. cit.) renders P. obsoletus paraphyletic with respect to the sister species P. bairdi. This, along with evidence showing that all four taxa are distinct lineages, indicates that they should remain at the species rank (Burbrink et al., 2020, op. cit.).
	*P. quadrivittatus* (Holbrook, 1836) — Yellow Ratsnake See comment under P. obsoletus.
	*P. ramspotti* (Crother, White, Savage, Eckstut, Graham and Gardner, 2011) — Western Foxsnake
	*P. slowinskii* (Burbrink, 2002) — Slowinski's Cornsnake See comment under P. guttatus
	*P. vulpinus* (Baird and Girard, 1853) — Eastern Foxsnake

Phyllorhynchus Stejneger, 1890 — Leaf-nosed Snakes

	*P. browni* Stejneger, 1890 — Saddled Leaf-nosed Snake
	*P. decurtatus* (Cope, 1868) — Spotted Leaf-nosed Snake

Pituophis Holbrook, 1842 — Bullsnakes

The English name for the genus is simplified to “Bullsnakes” because it is descriptive for all of the species.

P. catenifer (Blainville, 1835) — Gophersnake

	*P. c. affinis* Hallowell, 1852 — Sonoran Gophersnake
	*P. c. annectens* Baird and Girard, 1853 — San Diego Gophersnake
	*P. c. catenifer* (Blainville, 1835) — Pacific Gophersnake
	*P. c. deserticola* Stejneger, 1893 — Great Basin Gophersnake
	*P. c. pumilus* Klauber, 1946 — Santa Cruz Island Gophersnake
	*P. c. sayi* (Schlegel, 1837) — Bullsnake

P. melanoleucus (Daudin, 1803) — Eastern Pinesnake

Nikolakis et al. (2021, Zoologica Scripta 51: 133–146) analyzed ultra-conserved elements that showed P. melanoleucus to consist of continuous populations that did not correspond to previously recognized subspecies.

P. ruthveni Stull, 1929 — Louisiana Pinesnake

Rhinocheilus Baird and Girard, 1853 — Long-nosed Snakes

R. lecontei Baird and Girard, 1853 — Long-nosed Snake

Myers et al. (2019, Molecular Ecology 2019: 1–14) and Dahn et al. (2018, Molecular Phylogenetics and Evolution 129: 214–225 ) with two primary lineages on either side of the continental divide. This matches the classic split between the two morphological subspecies that Manier (2004, Biological Journal of the Linnaean Society 83: 65–85) examined. However, none of those studies suggested taxonomic changes.

Salvadora Baird and Girard, 1853 — Patch-nosed Snakes

Taxonomy follows Hernández-Jiménez et al. (2021, European Journal of Taxonomy 764: 85–118), who produced a phylogeny of the genus using parsimony analysis of morphological characters. They re-elevate S. deserticola and S. lineata to species. See also Myers et al. (2017, Journal of Biogeography 44: 461–474) and Myers et al. (2019, Molecular Ecology 2019: 1–14).

S. deserticola Schmidt, 1940 — Big Bend Patch-nosed Snake

See comment under Salvadora.

S. grahamiae Baird and Girard, 1853 — Mountain Patch-nosed Snake

The elevation of S. g. lineata leaves Salvadora grahamiae without subspecies. The standardized English name of the former subspecies S. g. grahamiae “Mountain Patch-nosed Snake” replaces the former species name for S. grahamiae “Eastern Patch-nosed Snake”

S. hexalepis (Cope, 1866) — Western Patch-nosed Snake

	*S. h. hexalepis* (Cope, 1866) — Desert Patch-nosed Snake
	*S. h. mojavensis* Bogert, 1945 — Mohave Patch-nosed Snake
	*S. h. virgultea* Bogert, 1935 — Coast Patch-nosed Snake

S. lineata Schmidt, 1940 — Texas Patch-nosed Snake

See comments under Salvadora.

Senticolis Dowling and Fries, 1987 — Green Ratsnakes

S. triaspis (Cope, 1866) — Green Ratsnake

Roth-Monzón et al. (2021, Ichthyology & Herpetology 109: 1026–1035), using morphometric and DNA data, detected a deep, north-South split in Senticolis populations along Mexico’s transverse volcanic province. However, they did not recommend taxonomic changes. See also Dahn et al. (2018, Molecular Phylogenetics and Evolution 129: 214–225).

S. t. intermedia (Boettger, 1883) — Northern Green Ratsnake

Sonora Baird and Girard, 1853 — North American Groundsnakes

Taxonomy follows Cox et al. (2018, Journal of Natural History 52: 945–988). Cox et al. used mt- and nDNA data to produce a phylogeny in which Chilomeniscus and Chionactis are paraphyletic with respect to Sonora. Their phylogeny also recommends modification of species content through resurrection and elevation of several taxa: Sonora cincta, S. episcopa, S. taylori .

S. annulata (Baird, 1859 “1858”) — Tricolor Shovel-nosed Snake

See comments under Sonora.

	*S. a. annulata* (Baird, 1859 “1858”) — Colorado Desert Shovel-nosed Snake See comments under Sonora.
	*S. a. klauberi* Stickel, 1941 — Tucson Shovel-nosed Snake See comments under Sonora.

S. cincta (Cope, 1861) — Banded Sandsnake

See comments under Sonora.

S. episcopa (Kennicott in Baird, 1859) — Great Plains Groundsnake

See comments under Sonora. The authority was corrected to reflect the name first appeared by Kennicott in a work by Baird.

S. occipitalis (Hallowell, 1854) — Mohave Shovel-nosed Snake

See comments under Sonora.

S. palarostris Klauber, 1937 — Sonoran Shovel-nosed Snake

See comments under Sonora.

S. p. organica (Klauber, 1951) — Organ Pipe Shovel-nosed Snake

See comments under Sonora.

S. semiannulata Baird and Girard, 1853 — Western Groundsnake

S. taylori (Boulenger, 1894) — South Texas Groundsnake

Tantilla Baird and Girard, 1853 — Black-headed Snakes

The English name for the genus is simplified to “Black-headed Snakes” because it is descriptive for nearly all of the species.

T. atriceps (Günther, 1895 in Salvin and Godman, 1885-1902) — Mexican Black-headed Snake

T. coronata Baird and Girard, 1853 — Southeastern Crowned Snake

T. cucullata Minton, 1956 — Trans-Pecos Black-headed Snake

T. gracilis Baird and Girard, 1853 — Flat-headed Snake

T. hobartsmithi Taylor, 1937 — Southwestern Black-headed Snake

The name was changed to “Smith’s Black-headed Snake” starting with the 7th edition (2012). “Southwestern” confers some geographic information about its range, and therefore we are returning to the previous name.

T. nigriceps Kennicott, 1860 — Plains Black-headed Snake

T. oolitica Telford, 1966 — Rim Rock Crowned Snake

T. planiceps (Blainville, 1835) — California Black-headed Snake

The English name was changed from "Western Black-headed Snake" to better relate to its geographic distribution relative to other Tantilla.

T. relicta Telford, 1966 — Florida Crowned Snake

Schrey et al. (2015, Journal of Herpetology 49: 415–419), using mtDNA data, found a genetic, north-South split in mid-peninsular populations.

	*T. r. neilli* Telford, 1966 — Central Florida Crowned Snake
	*T. r. pamlica* Telford, 1966 — Coastal Dunes Crowned Snake
	*T. r. relicta* Telford, 1966 — Peninsula Crowned Snake

T. wilcoxi Stejneger, 1902 — Chihuahuan Black-headed Snake

Date of publication corrected by Crombie (1994, Smithsonian Herpetological Information Service (101): 1–40).

T. yaquia Smith, 1942 — Yaqui Black-headed Snake

Trimorphodon Cope, 1861 — Lyresnakes

	*T. lambda* Cope, 1886 — Sonoran Lyresnake
	*T. lyrophanes* (Cope, 1860) — California Lyresnake
	*T. vilkinsonii* Cope, 1886 — Texas Lyresnake

Crotalidae Oppel, 1811 — Pit Vipers

Agkistrodon Palisot de Beauvois, 1799 — American Moccasins

	*A. conanti* Gloyd, 1969 — Florida Cottonmouth
	*A. contortrix* (Linnaeus, 1766) — Eastern Copperhead
	*A. laticinctus* Gloyd and Conant, 1934 — Broad-banded Copperhead
	*A. piscivorus* (Lacépède, 1789) — Northern Cottonmouth

Crotalus Linnaeus, 1758 — Greater Rattlesnakes

“Greater” was added to the English name to differentiate from the Pygmy Rattlesnakes, Sistrurus. One of the most vexing groups of Crotalus is the C. viridis complex. Davis et al. (2016, PLoS One 11: e0146166) used mtDNA and morphometric data that inferred six species within the C. viridis complex, which we do not completely follow pending further analyses. Taxa within this complex were examined by several authors in Schuett et al. (2016, Rattlesnakes of Arizona, Vol. I, Eco Publishing): Feldner et al.: 45–107 (In Schuett et al., 2016), discuss populations south and west of the Grand Canyon that are unassignable to C. o. abyssus, C. o. lutosus, or to C. cerberus; Davis et al.: 109–177 (In Schuett et al., 2016), relevance, in part, of assigning ‘C. viridis’ to seven species; Feldner et al.: 179–237 (In Schuett et al., 2016), ambiguities in assigning C. o. concolor populations as a cohesive taxon; Davis and Douglas: 289–332 (In Schuett et al., 2016), recognition of C. v. nuntius as a valid subspecies. In addition, Nikolakis et al. (2022, Evolution 76: 2513–2530) evaluated introgression in a hybrid zone between C. oreganus and C. viridis. Each of the preceding studies highlight population structure and/or taxonomy within the C. viridis complex, but do not recommend changes in our recognition of three species of the complex: C. cerberus, C. oreganus, and C. viridis.

C. adamanteus Palisot de Beauvois, 1799 — Eastern Diamond-backed Rattlesnake

C. atrox Baird and Girard, 1853 — Western Diamond-backed Rattlesnake

Castoe et al. (2007, Molecular Phylogenetics and Evolution 42: 193–212), using mtDNA, found two primary lineages, Sonoran (western) and Chihuahuan (eastern), but with sufficient admixture to render taxonomic division untenable. Spencer (2008, In Hayes et al., Biol. Rattlesnakes: 55–78) found morphological variation in C. atrox to be clinal, representing one continuously distributed population. See also Myers et al. (2017, Journal of Biogeography 44: 461–474). Additionally, Schield et al. (2015, Molecular Phylogenetics and Evolution 83: 213–223) and Myers et al. (2019, Molecular Ecology 28: 4535–4548) found two lineages distributed in the Chihuahuan and Sonoran Deserts hybridizing at the Cochise Filter Barrier.

C. cerastes Hallowell, 1854 — Sidewinder

	*C. c. cerastes* Hallowell, 1854 — Mohave Desert Sidewinder
	*C. c. cercobombus* Savage and Cliff, 1953 — Sonoran Sidewinder
	*C. c. laterorepens* Klauber, 1944 — Colorado Desert Sidewinder

C. cerberus (Coues, 1875) — Arizona Black Rattlesnake

See annotations under Crotalus. Douglas et al. (2016, Royal Society Open Science 3[160047]: 1–11) found five lineages within C. cerberus using mtDNA data.

C. horridus Linnaeus, 1758 — Timber Rattlesnake

C. lepidus (Kennicott, 1861) — Rock Rattlesnake

	*C. l. klauberi* Gloyd, 1936 — Banded Rock Rattlesnake
	*C. l. lepidus* (Kennicott, 1861) — Mottled Rock Rattlesnake

C. molossus Baird and Girard, 1853 — Black-tailed Rattlesnake

Muñoz-Mora et al. (2022, Herpetozoa 35: 141–153) examined mtDNA variation that included numerous Mexican populations. Three lineages were found that correspond to currently recognized subspecies of C. molossus. The authors suggested that the lineages likely represented species but did not make taxonomic changes pending information from nDNA. See also Myers et al. (2017, Journal of Biogeography 44: 461–474 and Myers et al. (2019, Molecular Ecology 28: 4535–4548).

C. m. molossus Baird and Girard, 1853 — Northern Black-tailed Rattlesnake

C. oreganus Holbrook, 1840 — Western Rattlesnake

See comments under Crotalus, above.

	*C. o. abyssus* Klauber, 1930 — Grand Canyon Rattlesnake
	*C. o. concolor* Woodbury, 1929 — Midget Faded Rattlesnake
	*C. o. helleri* Meek, 1906 “1905" — Southern Pacific Rattlesnake
	*C. o. lutosus* Klauber, 1930 — Great Basin Rattlesnake
	*C. o. oreganus* Holbrook, 1840 — Northern Pacific Rattlesnake

C. ornatus Hallowell, 1854 — Eastern Black-tailed Rattlesnake

C. pricei Van Denburgh, 1895 — Twin-spotted Rattlesnake

C. p. pricei Van Denburgh, 1895 — Western Twin-spotted Rattlesnake

C. pyrrhus (Cope, 1867 “1866”) — Southwestern Speckled Rattlesnake

C. ruber Cope, 1892 — Red Diamond Rattlesnake

C. scutulatus (Kennicott, 1861) — Mohave Rattlesnake

Schield et al. (2018, Molecular Phylogenetics and Evolution 127: 669–681), using thousands of ddRAD loci and mtDNA found four lineages within C. scutulatus, with the deepest node differentiating Mexican Plateau populations + C. s. salvini from those to the north. The northern populations formed two lineages on either side of the Continental Divide; the authors state that current taxonomy does not capture the diversity within C. scutulatus but they do not specifically recommend taxonomic changes. See also Myers et al. (2017, Journal of Biogeography 44: 461–474) and Myers et al. (2019, Molecular Ecology 28: 4535–4548 ). Note, Myers et al. (2019, op. cit.) did not find structure at the continental divide. Watson et al. (2019, Zootaxa 4683: 129–143) evaluated morphology throughout the geographic range and found that variation was clinal without discrete character change at genetic boundaries. They recommended retention of the two classic subspecies.

C. s. scutulatus (Kennicott, 1861) — Northern Mohave Rattlesnake

C. stephensi Klauber, 1930 — Panamint Rattlesnake

C. tigris Kennicott, in Baird, 1859 — Tiger Rattlesnake

C. viridis (Rafinesque, 1818) — Prairie Rattlesnake

See comments under Crotalus.

C. willardi Meek, 1906, “1905” — Ridge-nosed Rattlesnake

	*C. w. obscurus* Harris and Simmons, 1976 — New Mexico Ridge-nosed Rattlesnake
	*C. w. willardi* Meek, 1906, “1905” — Arizona Ridge-nosed Rattlesnake

Sistrurus Garman, 1883 — Pygmy Rattlesnakes

The English name was simplified to one that characterized all of the species within the genus.

S. catenatus (Rafinesque, 1818) — Eastern Massasauga

S. miliarius (Linnaeus, 1766) — Pygmy Rattlesnake

	*S. m. barbouri* Gloyd, 1935 — Dusky Pygmy Rattlesnake
	*S. m. miliarius* (Linnaeus, 1766) — Carolina Pygmy Rattlesnake
	*S. m. streckeri* Gloyd, 1935 — Western Pygmy Rattlesnake

S. tergeminus (Say in James, 1822) — Western Massasauga

Date of publication is corrected to 1822 based on Woodman (2010, Archives of Natural History 37: 28–38).

	*S. t. edwardsii* (Baird and Girard, 1853) — Desert Massasauga
	*S. t. tergeminus* (Say in James, 1822) — Prairie Massasauga The date of publication is corrected to 1822 based on Woodman (2010, Archives of Natural History 37: 28–38).

Dipsadidae Bonaparte, 1838 — Harmless Rear-Fanged Snakes

Carphophis Gervais in D’Orbigny, 1843 — North American Wormsnakes

The authority was corrected to reflect that the name was proposed in a work by D'Orbigny.

C. amoenus (Say, 1825) — Common Wormsnake

	*C. a. amoenus* (Say, 1825) — Eastern Wormsnake
	*C. a. helenae* (Kennicott, 1859) — Midwestern Wormsnake

C. vermis (Kennicott, 1859) — Western Wormsnake

Coniophanes Hallowell in Cope, 1860 — Black-striped Snakes

The authority was corrected to reflect that the name was proposed in a paper solely authored by Cope.

C. imperialis (Baird and Girard, 1859) — Regal Black-striped Snake

C. i. imperialis (Baird and Girard, 1859) — Tamaulipan Black-striped Snake

Contia Baird and Girard, 1853 — Sharp-tailed Snakes

	*C. longicauda* Feldman and Hoyer, 2010 — Forest Sharp-tailed Snake
	*C. tenuis* (Baird and Girard, 1852) — Common Sharp-tailed Snake

Diadophis Baird and Girard, 1853 — Ring-necked Snakes

D. punctatus (Linnaeus, 1766) — Ring-necked Snake

Fontanella et al. (2008, Molecular Phylogenetics and Evolution 46: 1049–1070) found at least 14 mtDNa-based lineages that do not always follow the geographic range of the currently recognized subspecies. Fontanella et al. (2017, Zoological Journal of the Linnean Society 182: 444–458) evaluated the contact zone between two of the lineages (D. p. edwardsi North and D. p. edwardsi South). Morphological differences between these two lineages were clinal, whereas mtDNA sequence data were discrete but with zones of secondary contact. Our arrangement follows the traditional subspecies groupings.

	*D. p. acricus* Paulson, 1968 — Key Ring-necked Snake
	*D. p. amabilis* Baird and Girard, 1853 — Pacific Ring-necked Snake
	*D. p. arnyi* Kennicott, 1859 — Prairie Ring-necked Snake
	*D. p. edwardsii* (Merrem, 1820) — Northern Ring-necked Snake
	*D. p. modestus* Bocourt, 1886 in Duméril, Mocquard, and Bocourt, 1870-1909 — San Bernardino Ring-necked Snake
	*D. p. pulchellus* Baird and Girard, 1853 — Coral-bellied Ring-necked Snake
	*D. p. punctatus* (Linnaeus, 1766) — Southern Ring-necked Snake
	*D. p. regalis* Baird and Girard, 1853 — Regal Ring-necked Snake
	*D. p. stictogenys* Cope, 1860 — Mississippi Ring-necked Snake

Farancia Gray, 1842 — North American Mudsnakes

The English name was simplified to one that characterized all of the species within the genus.

F. abacura (Holbrook, 1836) — Red-bellied Mudsnake

	*F. a. abacura* (Holbrook, 1836) — Eastern Mudsnake
	*F. a. reinwardtii* Schlegel, 1837 — Western Mudsnake

F. erytrogramma (Palisot de Beauvois in Sonnini de Manoncourt and Latreille, 1801) — Rainbow Snake

	*F. e. erytrogramma* (Palisot de Beauvois in Sonnini de Manoncourt and Latreille, 1801) — Common Rainbow Snake
	*F. e. seminola* Neill, 1964 — Southern Florida Rainbow Snake

Heterodon Latreille in Sonnini de Manoncourt and Latreille, 1801 — North American Hog-nosed Snakes

The authority corrected to note that Latreille named this taxon within a work authored by Sonnini and Latreille.

H. kennerlyi Kennicott, 1860 — Mexican Hog-nosed Snake

H. nasicus Baird and Girard, 1852 — Western Hog-nosed Snake

The previously used, more inclusive English name is used when recognizing the two subspecies. Werler and Dixon (2000, Texas Snakes: Identification, Distribution, and Natural History. University of Texas Press, Austin) regarded H. n. gloydi to be an allopatric, diagnosable taxon restricted to the low plains – eastern forest ecotone of east Texas. Smith et al. (2003, Journal of Kansas Herpetology : 17–20) accepted previous conclusions that H. n. gloydi is a synonym of H. n. nasicus, but they were receptive to re-evaluating gloydi as a valid taxon. In this equivocal situation, we choose to retain these subspecies pending genetic evaluation of H. nasicus.

	*H. n. gloydi* Edgren, 1952 — Dusty Hog-nosed Snake See comment under H. nasicus.
	*H. n. nasicus* Baird and Girard, 1852 — Plains Hog-nosed Snake See comment under H. nasicus.

H. platirhinos Palisot de Beauvois in Sonnini de Manoncourt and Latreille, 1801 — Eastern Hog-nosed Snake

The authority is corrected to reflect that Palisot de Beauvois described platirhinos in a foot-noted section within Sonnini and Latreille.

H. simus (Linnaeus, 1766) — Southern Hog-nosed Snake

Hypsiglena Cope, 1860 — North American Nightsnakes

Based on mtDNA data, Myers and Mulcahy (2020, Mitochondrial DNA Part B Resources. 5: 3056–3058) recognized nine named and two unnamed (presumed) species. Three or their named and one of their unnamed species occur in the U.S. The nine named species closely follow the boundaries of taxa formerly recognized as subspecies. The authors continue to recognize subspecies designations within several of the widespread, polymorphic species. See also Myers et al. (2017, Journal of Biogeography 44: 461–474) and Myers et al. (2019, Molecular Ecology 28: 4535–4548.).

H. chlorophaea Cope, 1860 — Desert Nightsnake

	*H. c. chlorophaea* Cope, 1860 — Sonoran Nightsnake
	*H. c. deserticola* Tanner, 1944 — Northern Desert Nightsnake The authority has been corrected, and parentheses have been removed from previous versions of this list.
	*H. c. loreala* Tanner, 1944 — Mesa Verde Nightsnake The authority has been corrected, and parentheses have been removed from previous versions of this list.

H. jani (Dugès, 1865) — Chihuahuan Nightsnake

H. j. texana Stejneger, 1893 — Texas Nightsnake

The authority has been corrected, and parentheses have been removed from previous versions of this list.

H. ochrorhyncha Cope, 1860 — Coast Nightsnake

	*H. o. klauberi* Tanner, 1944 — San Diego Nightsnake
	*H. o. nuchalata* Tanner, 1943 — California Nightsnake The authority has been corrected, and parentheses have been removed from previous versions of this list.

Leptodeira Fitzinger, 1843 — Cat-eyed Snakes

Taxonomy follows Barrio-Amorós (2019, Reptiles & Amphibians 26: 1–15).

L. septentrionalis (Kennicott, in Baird, 1859) — Northern Cat-eyed Snake

Following the mtDNa-based phylogeny in Daza et al. (2009, Molecular Phylogenetics and Evolution 53: 653–657), including the unique color pattern of the taxon, Wallach et al. (2014, Snakes of the World: A Catalogue of Living and Extinct Species. CRC Press, Boca Raton, Florida) and Barrio-Amorós (2019, Reptiles & Amphibians 26: 1–15) consider L. septentrionalis to be restricted to its former subspecific concept in northeastern Mexico and southern Texas.

Rhadinaea Cope, 1863 — Littersnakes

R. flavilata (Cope, 1871) — Pine Woods Littersnake

Elapidae Boie, 1827 — Coral Snakes, Cobras, and Kraits

Micruroides Schmidt, 1928 — Sonoran Coralsnakes

M. euryxanthus (Kennicott, 1860) — Sonoran Coralsnake

M. e. euryxanthus (Kennicott, 1860) — Arizona Coralsnake

Micrurus Wagler, 1824 — American Coralsnakes

The authority corrected to relate that Wagler the taxon in a work authored by Spix.

	*M. fulvius* (Linnaeus, 1766) — Harlequin Coralsnake
	*M. tener* (Baird and Girard, 1853) — Texas Coralsnake Streicher et al. (2016, Evolution 70: 1435–1449, recognized no subspecies within M. tener

Hydrophiidae Fitzinger, 1843 — Sea Snakes and Allies

Hydrophis Latreille in Sonnini de Manoncourt and Latreille, 1801 — Circum-tropical Seasnakes

The English name was changed to differentiate from the family group name, and there are other sea snake genera. Authority corrected from "Latreille ex Sonnini and Latreille, 1801" in prior editions of this list.

H. platurus (Linnaeus, 1766) — Yellow-bellied Seasnake

Bessesen and Galbreath (2017, ZooKeys 686: 109–123) described a localized subspecies of H. platurus in Costa Rica that differs from the nominate race in size, coloration, locality, and habits. The nominate race occurs in the U.S.

H. p. platurus (Linnaeus, 1766) — Common Yellow-bellied Sea Snake

No subspecies were recognized for this taxon in the prior list.

Leptotyphlopidae Stejneger, 1891 — Threadsnakes

Rena Baird and Girard, 1853 — North American Threadsnakes

“North American” is added to the English name to differentiate Rena from other Threadsnake genera. Taxonomy follows Flores-Villela et al. (2022, Revista Mexicana de Biodiversidad 93: e933933), who reviewed geographical variation in morphology and modified the taxonomic results of previous studies: R. dissecta is re-synonymized with R. dulcis, and R. segrega is elevated to species. No subspecies are recognized.

	*R. dulcis* Baird and Girard, 1853 — Texas Threadsnake
	*R. humilis* Baird and Girard, 1853 — Western Threadsnake
	*R. segrega* Klauber, 1939 — Trans-Pecos Threadsnake See comment under Rena.

Natricidae Bonaparte, 1838 — Harmless Egg-Retaining Snakes

Clonophis Cope, 1889 — Kirtland's Snakes

C. kirtlandii (Kennicott, 1856) — Kirtland's Snake

Liodytes (Cope, 1885) — Nearctic Swampsnakes

“Nearctic” is added to the English name to differentiate Liodytes from other World snake genera that are called Swampsnakes. Using genome-scale data, Nuñez et al. (2023, Molecular Phylogenetics and Evolution 186(107844: 1-12) found that L. pygaea was sister to L. alleni and L. rigida. They recommend returning L. pygaea to the genus Seminatrix. We retain the classic subspecies –– they have not been addressed in any modern study.

L. alleni (Garman, 1874) — Striped Swampsnake