A reclassification of the Rattlesnakes; species formerly exclusively referred to the Genera Crotalus and Sistrurus.


Raymond Hoser
488 Park Road, Park Orchards, Victoria, 3114, Australia.

Phone: +61 3 9812 3322 Fax: 9812 3355 E-mail: adder@smuggled.com

Submitted 24 February 2009, Accepted 1 March 2009, Published 8 March 2009.

Originally published in hard copy in Australasian Journal of Herpetology Issue 6 (9 March 2009):1-21.



In spite of the fact that the taxonomy of most rattlesnakes at the species level has been established for many years, the genus Crotalus as referred to by most taxonomists up to 2008 failed to properly distinguish relationships within the group commonly defined as “rattlesnakes”.  The genera Crotalus and Sistrurus (the latter sometimes subsumed in whole or part within Crotalus) as defined by most authors also fails to properly delineate relationships between taxa and fails to account for the modern definition and use of the “genus” level in terms of grouping closely related species only.

This paper principally redefines the rattlesnakes at both genus and subgenus levels, formally naming a number of well-recognised species and species groups at the genus level for the first time.

In summary rattlesnakes are subdivided into nine genera for which names were previously available for a total of five.  For the other four genera, they are formally defined, diagnosed and named for the first time.

A further seven well-defined subgenera are also defined and named for the first time.

Later workers may choose to elevate some or all of these to full genus level.

Keywords: new taxa, snake, rattlesnake, taxonomy, Crotalus, Sistrurus, Piersonus, Matteoea, Cummingea, Hoserea, Caudisona, Aechmophrys, Uropsophus, Cottonus, Smythus, Pillotus, Sayersus, Mullinsus, Edwardsus, Crutchfieldus.


Link to full paper is here:


Link to list of recognized taxa and their generic and subgeneric classifications:

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