THE CENTER FOR NORTH AMERICAN HERPETOLOGY

Reptilia    Squamata (part-snakes)    Colubridae  

Tricolor Shovel-nosed Snake
Sonora annulata (Baird, 1859)
soh-NOHR-ah — an-yoo-LAY-tuh

SSAR 9th Edition Comments:
 See comments under Sonora. (Boundy, Jeff, Frank T. Burbrink, and Sara Ruane. 2025. Squamata (excluding lizards) – Snakes. Pages 38-54 in Kirsten E. Nicholson (Editor), Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding, 9th Edition. Society for the Study of Amphibians and Reptiles, Lawrence, Kansas. 87 pp.)

Range maps are based on curated specimens and provided gratis by CNAH.
(Created by Travis W. Taggart; Version: 2024.02.01.13.49.55)
Download GeoJSON polygon range file: - 0.07 MB

Province/State Distribution:
United States: Arizona California

Taxonomic Etymology:
Named for its ringed color pattern.
Sonora — Named after the Sonoran Desert or Sonora state in Mexico, referencing the region where many species in the genus are found.
annulata — From Latin annulatus, meaning “ringed.” Refers to the prominent dark bands encircling the body in many individuals.

First instance(s) of published English names:
Colorado Desert Shovel-nosed Snake (Chionactis occipitalis annulata: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);

Taxon Links:

  
Catalog of American Amphibians and Reptiles
  
The Reptile Database
  
NatureServe
  
iNaturalist
  
GenBank
  
USGS - Nonindigenous Aquatic Species Database

Selected References:
1859 "1858" Baird, Spencer F. Reptiles of the Boundary, in: Volume 2, pt. 2 United States and Mexican Boundary Survey, U.S. 34th Congress, 1st Session, Executive Document 108. 1-35pp.
2012 Cox, Christian L. Phylogenetic systematics, populations genetics, and the evolution of color pattern polymorphism and coral snake mimicry in the snake genus Sonora. Dissertation. University of Texas at Arlington, Arlington, Texas. 159pp.
2013 Cox, Christian L. and Alison R. Davis Rabosky. Spatial and temporal drivers of phenotypic diversity in polymorphic snakes. The American Naturalist 182(2):E40-E57
2014 Cox, Christian L. and Paul T. Chippindale. Patterns of genetic diversity in the polymorphic ground snake (Sonora semiannulata). Genetica 142:361-370
2016 Davis Rabosky, Alison R., Christian L. Cox, Daniel L. Rabosky, Pascal O. Title, Iris A. Holmes, Anat Feldman, and Jimmy A. McGuire. Coral snakes predict the evolution of mimicry across New World snakes Nature Communications 7(11484):1-9
2017 Bezy, Robert L., Philip C. Rosen, Thomas R. Van Devender, and Erik F. Enderson. Southern distributional limits of the Sonoran Desert herpetofauna along the mainland coast of northwestern Mexico Mesoamerican Herpetology 4(1):138-167

THE CENTER FOR NORTH AMERICAN HERPETOLOGY — Accessed: Friday 05 December 2025 15:56 CT