You are here » home advanced search search results Sonora occipitalis

Sonora occipitalis (HALLOWELL, 1854)

Can you confirm these amateur observations of Sonora occipitalis?

Add your own observation of
Sonora occipitalis »

Find more photos by Google images search: Google images

Higher TaxaColubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)
Common NamesE: Western Shovelnose Snake
occipitalis: Mojave Shovelnose Snake
talpina: Nevada Shovelnose Snake
G: Westliche Schaufelnasenschlange
S: Rostro de Pala Occidental 
SynonymRhinostoma occipitale HALLOWELL 1854: 95
Lamprosoma occipitale — HALLOWELL 1856: 311.
Chionactis occipitale — COPE 1860: 241 (nom. subst.)
Chionactis occipitalis — COOPER 1870: 66
Homalosoma occipitale — MÜLLER 1882: 125
Contia occipitalis — GARMAN 1884: 91
Contia occipitalis — GARMAN 1884a: 91
Contia occipitaIe — BROWN 1901: 68 (part)
Chioractis occipitalis — MEEK 1905: 15
Sonora occipitalis — VAND ENBRUGH & SLEVIN 1913:412 (part)
Sonora occipitalis — STICKEL 1938: 183
Sonora occipitalis — STICKEL 1941
Chionactis occipitalis talpina KLAUBER, 1951: 172
Chionactis saxatilis FUNK 1967
Chionactis occipitalis — STEBBINS 1985: 213
Chionactis occipitalis occipitalis — MEHRTENS 1987: 178
Chionactis occipitalis — LINER 1994
Chionactis saxatilis — COLLINS 1997
Chionactis occipitalis talpina — CROTHER 2000: 58
Chionactis occipitalis talpina — SCHMIDT & KUNZ 2005: 110
Chionactis occipitalis talpina — CROTHER et al. 2012
Chionactis occipitalis — CROTHER et al. 2012
Chionactis occipitalis — WALLACH et al. 2014: 160
Sonora occipitalis — COX et al. 2018: 975
Chionactis occipitalis — LILLYWHITE 2022 
DistributionUSA (SE California, S Nevada, SW Arizona),
Mexico (Baja California Norte)

Type locality: Mohave Desert of California.

saxatilis (invalid): USA (Arizona); Type locality, "Gila Mountains, Yuma Co., Ariz., ca. 2.5 air miles northeast (in T. 10S.. R.20W) ofFortuna Mine at an elevation of ca. 2300 feet above sea level."

talpina (invalid): extreme S Nevada; Type locality: "50 miles south of Goldfield on the highway to Beatty, in Nye County, Nevada."  
TypesHolotype: USNM 8030, figured in Hallowell 1859 (plate IV, fig. 2a-c).
Holotype: CAS 81364; Paratypes: SDNHM = SDSNH 39520, 39521 [talpina]
Holotype: MCZ 77039 [saxatilis] 
DiagnosisDiagnosis: Sonora occipitalis can be distinguished from all other Sonora, except S. annulata and S. palarostris, by the presence of a flattened, spadelike rostrum. Sonora occipitalis can generally be distinguished from both S. annulata and S. palarostris by the lack of red crossbands (usually present in both S. palarostris and S. annulata) and the brown coloration of crossbands. Additional morphological differences among S. occipitalis, S. palarostris and S. annulata are summarized in Wood et al. (2014) (Cox et al. 2018: 975).

Variation: Most S. occipitalis lack red crossbands, but some populations have individuals with red crossbands (less than 10%). There is variation in the number of black crossbands, but there are usually more than 45 (Cox et al. 2018: 975).

Klauber considered the composite character ‘‘number of dark bands on the body plus unmarked anterior band positions on the ventrum’’ to be the most important numerical character distinguishing C. o. annulata from C. o. occipitalis and arbitrarily assigned a threshold that defined C. o. annulata as having ‘‘usually fewer than 45’’. He further observed that about 20% of C. o. occipitalis specimens fell below this criterion and about 10% of C. o. annulata specimens have 45 or more.

Traditionally, subspecies are distinguished partly by ventral scale counts and number of dark bands encircling the body, but the most striking variation is in pattern and coloration of secondary bands (Stickel 1941; Klauber 1951). 
CommentSynonymy: mostly after Mahrdt et al. 2001.

Subspecies: Chionactis occipitalis talpina KLAUBER 1951 has been synonymized with C. occipitalis by WOOD et al. 2014 who also moved the other subspecies to C. annulata. Wood et al. (2008) concluded that “Neither molecular nor morphological data are concordant with the traditional C. occipitalis subspecies taxonomy. Mitochondrial sequences suggest specimens recognized as C. o. klauberi are embedded in a larger geographic clade whose range has expanded from western Arizona populations, and these data are concordant with clinal longitudinal variation in morphology.” Consequently, the subspecies of C. occipitalis should be rejected.

Type species: Rhinostoma occipitale HALLOWELL 1854: 95 is the type species of the genus Chionactis COPE 1860: 241. Lamprosoma is pre-occupied by a genus oc Coleoptera.

Distribution: not in Sonora fide Lemos-Espinal et al. 2019 and Cox et al. 2018: 976 although the map in the latter (Fig. 5) is ambiguous about the distribution. 
EtymologyThe name occipitalis is derived from the Latin occipit meaning the back of the head, in reference to "the occipital crescent blotch" (Baird 1859a). 
  • Astley, Henry C.; Joseph R. Mendelson, III, Jin Dai, Chaohui Gong, Baxi Chong, Jennifer M. Rieser, Perrin E. Schiebel, Sarah S. Sharpe, Ross L. Hatton, Howie Choset and Daniel I. Goldman 2020. Surprising simplicities and syntheses in limbless self-propulsion in sand. Journal of Experimental Biology 223: jeb103564, doi:10.1242/jeb.103564 - get paper here
  • Baird, S.F. 1859. Reptiles of the Boundary. In: United States and Mexican Boundary Survey under the Order of Lieut. Col. W. H. Emory, Major First Cavalry, and United States Commisioner. 2, Rept., Pt.2. Department of the Interior, Washington, 35 pp. - get paper here
  • Banta, Benjamin H. 1953. Some herpetological notes from southern Nevada. Herpetologica 9: 75-76 - get paper here
  • Barts, M. 2009. Chionactis occipitalis annulata (BAIRD). Sauria 31 (4): 2 - get paper here
  • Collins J T 1997. Standard Common and current scientific names for North American amphibians and reptiles, 4th edition. Herpetological Circular 25: 1-40
  • Cox, Christian L.; Alison R. Davis Rabosky, Iris A. Holmes, Jacobo Reyes-Velasco, Corey E. Roelke, Eric N. Smith, Oscar Flores-Villela, Jimmy A. McGuire & Jonathan A. Campbell 2018. Synopsis and taxonomic revision of three genera in the snake tribe Sonorini. Journal of Natural History 52: 945-988 - get paper here
  • Crother, B. I. (ed.) 2012. Standard Common and Current Scientific Names for North American Amphibians, Turtles, Reptiles, and Crocodilians, Seventh Edition. Herpetological Circular 39: 1-92
  • Friedrich, U. 2007. Lebendfutter für Amphibien und Reptilien - Geschichte und Grundlagen. Draco 7 (28): 4-21 [2006] [Sonderheft Lebendfutter] - get paper here
  • Funk, Richard S. 1967. A New Colubrid Snake of the Genus Chionactis from Arizona. Southwestern Naturalist 12 (2): 180 - get paper here
  • Garman,Samuel 1884. The reptiles and batrachians of North America. Mem. Mus. comp. Zool, Cambridge (Massachusetts), 8 (3): xxxiv + 185 pp. [1883] [CNAH reprint 10] - get paper here
  • González-Romero, A., & Alvarez-Cárdenas, S. 1989. Herpetofauna de la Region del Pinacate, Sonora, Mexico: Un Inventario. The Southwestern Naturalist, 34(4), 519–526 - get paper here
  • Goode, Matthew J.;Schuett, Gordon W. 1994. Male combat in the western shovelnose snake (Chionactis occipitalis). Herpetological Natural History 2 (1): 115-117
  • Hallowell,E. 1854. Description of new reptiles from California. Proc. Acad. Nat. Sci. Philad. 7 [1854]: 91-97 - get paper here
  • Heimes, P. 2016. Snakes of Mexico. Chimaira, Frankfurt, 572 pp
  • Klauber, Laurence M. 1951. The shovel-nosed snake, Chionactis with descriptions of two new subspecies. Transactions of the San Diego Society of Natural History 11 (9): 141-204 - get paper here
  • Kunz, K. 2006. Zerteilen von Beute bei Schlangen. Reptilia (Münster) 11 (59): 6-7 - get paper here
  • Kunz, K. 2012. Kleine Tiere, kleine Terarrien, großer Anspruch: Nano-Terraristik!. Reptilia (Münster) 17 (97): 22-31 - get paper here
  • Kunz, Kriton 2015. Schlangen, die Wirbellose fressen. Terraria-Elaphe 2015 (5): 14-20 - get paper here
  • Lillywhite, H.B. 2022. Discovering snakes in wild places. ECO Publishing, Rodeo, NM, 164 pp.
  • Love, B. 2014. Neue Horizonte. Reptilia (Münster) 19 (108): 14-15
  • Mahrdt, Clark R., Kent R. Beaman, Philip C. Rosen and Peter A. Holm 2001. Chionactis occipitalis (Hallowell) Western Shovel-nosed Snake. Catalogue of American Amphibians and Reptiles (731): 1-12 - get paper here
  • Mahrdt, Clark R., Kent R. Beaman, Philip C. Rosen and Peter A. Holm 2001. Chionactis Cope Shovel-nosed Snakes. Catalogue of American Amphibians and Reptiles (730): 1-6 - get paper here
  • Mehrtens, J.M. 1987. Living snakes of the world in color. Sterling Publ. Co., hic., New York, NY: 480 pp.
  • Rorabaugh, J.C. 2002. Diurnal activity and a minimum population density estimate of the Colorado Desert Shovel-nosed Snake (Chionactis occipitalis annulata). Sonoran Herpetologist 15 (4):42-43. - get paper here
  • Rorabaugh, J.C. 2014. Western Shovel-nosed Snake (Chionactis occipitalis). Herpetofauna of the 100 Mile Circle. Sonoran Herpetologist 27 (2):38-44. - get paper here
  • Schmidt, D. & Kunz, K. 2005. Ernährung von Schlangen. Natur und Tier Verlag, Münster, 159 pp. - get paper here
  • Stebbins,R.C. 1985. A Field Guide to Western Reptiles and Amphibians, 2nd ed. Houghton Mifflin, Boston
  • Stickel, W.H. 1943. The Mexican snakes of the genera Sonora and Chionactis with notes on the status of other colubrid genera. Proc. Biol. Soc. Washington 56: 109-128 - get paper here
  • Stickel, William H. 1938. The snakes of the genus Sonora in the United States and Lower California. Copeia 1938 (4): 182-190 - get paper here
  • Stickel, William H. 1941. The subspecies of the spade-nosed snake, Sonora occipitalis. Bull. Chicago Acad. Sci. 6: 135-140
  • Wallach, Van; Kenneth L. Williams , Jeff Boundy 2014. Snakes of the World: A Catalogue of Living and Extinct Species. [type catalogue] Taylor and Francis, CRC Press, 1237 pp.
  • Werning, Heiko 2012. Die Reptilien und Amphibien des Südwestens. Draco 13 (50): 18-60 - get paper here
  • Whitford, Malachi; Grace Freymiller, Jessica Ryan, Drew Steele, Corrina Tapia, Rulon W. Clark 2017. Chionactis occipitalis: hypomelanism. Herpetology Notes 10: 411-412 - get paper here
  • Wood DA, Fisher RN, Vandergast AG 2014. Fuzzy Boundaries: Color and Gene Flow Patterns among Parapatric Lineages of the Western Shovel-Nosed Snake and Taxonomic Implication. PLoS One 9 (5): e97494. doi:10.1371/journal.pone.0097494 - get paper here
  • Wood, D.A.; Meik, J.M.; Holycross, A.T.; Fisher, R.N. & Vandergast, A.G. 2008. Molecular and phenotypic diversity in Chionactis occipitalis (Western Shovel-nosed Snake), with emphasis on the status of C. o. klauberi (Tucson Shovel-nosed Snake). Conservation Genetics 9:1489–1507 - get paper here
External links  
Is it interesting? Share with others:

As link to this species use URL address:

without field 'search_param'. Field 'search_param' is used for browsing search result.

Please submit feedback about this entry to the curator