Crotalus armstrongi CAMPBELL, 1979
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Crotalus armstrongi
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| Higher Taxa | Viperidae, Crotalinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes) |
| Subspecies | |
| Common Names | E: Mexican Dusky Rattlesnake S: Chiauhcoatl de Armstrong |
| Synonym | Crotalus triseriatus armstrongi CAMPBELL 1979: 365 Crotalus triseriatus armstrongi — BEAMAN & HAYES 2008 Crotalus triseriatus armstrongi — MAYER-GOYENECHEA & GUAL-DIAZ 2014: 275 Crotalus armstrongi — BRYSON et al. 2014 Crotalus armstrongi — GARCÍA-PADILLA et al. 2025 |
| Distribution | Mexico (Jalisco, Nayarit) Type locality: "Rancho San Francisco, 1.5 mi NW Tapalpa, Jalisco, Mexico, elevation 2103 m." |
| Reproduction | ovoviviparous. |
| Types | Holotype: UTA R6258 |
| Diagnosis | Diagnosis: Crotalus triseriatus armstrongi can be distinguished by its pale gray, reddish brown, brownish yellow, or yellowish green ground color from C. t. triseriatus which has a dark gray or dark grayish brown dorsum. In C. t. armstrongi the body blotches tend to be as wide orwider than long while in C. t. triseriatus the blotches are usualIy Ionger than wide. Crotalus t. armstrongi further differs from C. t. triseriatus in that males (N=3) generally have fewer ventrals and subcaudals, 130-138 (134.3) and 24-26 (25.3), respectively, as compared to 136-151 (144.0) and 26-34 (29.2), respectively. Crotalus t. armstrongi can be distinguished from C. t. aquilus by having a distinct postocular stripe, a proportionally smaller rattle, and in males possessing fewer ventrals (the number usually exceeding 145 in C. t. aqutlus). Crotalus t. armstrongi females (N= 6) generally have fewer ventrals, 138-146 (142.0), and more subcaudals, 22-25 (23.5) than female C. t. aquilus which have 143-160 (151.7) ventrals and 17-23 (20.4) subcaudals. The only other rattlesnake with which C. t. armstrongi may be confused is C. pusillus, but it may be easily distinguished from this form by its having fewer ventrals and subcaudals,fewer pterygoid teeth, and canthals that fall to make contact with each other (Campbell 1979: 366). |
| Comment | Venomous! Nomenclature: Hoser’s 2009 classification and nomenclature has been rejected as unnecessary and unavailable by WÜSTER & BERNILS 2011. Synonymy: Listed as a synonym of Crotalus triseriatus by WALLACH et al. 2014: 197. Conservation: one of the 30 most endangered viper species (Maritz et al. 2016). Distribution: see map in Blair et al. 2018: 352 (Fig. 1) |
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