Sonora cincta, (Cope 1861)

Cox, Christian L., Davis Rabosky, Alison R., Holmes, Iris A., Reyes-Velasco, Jacobo, Roelke, Corey E., Smith, Eric N., Flores-Villela, Oscar, McGuire, Jimmy A. & Campbell, Jonathan A., 2018, Synopsis and taxonomic revision of three genera in the snake tribe Sonorini, Journal of Natural History 52 (13 - 16), pp. 945-988 : 971-972

Sonora cincta ( Cope 1861)

Chilomeniscus cinctus Cope 1861:303 . Holotype: Museum of Comparative Zoology (MCZ)

24. Type locality: near the town of Guaymas , Sonora, Mexico. Chilomeniscus ephippicus Cope 1867:85 . Holotype: USNM 8997 . Type locality: Arizona or

Owens Valley, California. Chilomeniscus cinctus Banta and Leviton 1963:321 Chilomeniscus stramineus Grismer et al. 2002:28 Chilomeniscus cinctus Holm 2008:29

Diagnosis

Sonora cincta can be distinguished from all other Sonora except for S. fasciata and S. straminea by the presence of an elongated rostrum. Unlike S. straminea , S. cincta does not have apical maculations on dorsal body scales ( Holm 2008). There are no simple morphological measurements to distinguish S. fasciata and S. cincta , but Holm (2008) presents a formula that uses a pattern of head squamation to distinguish these two taxa. Geographic range may in fact be the most reliable way to distinguish S. fasciata from S. cincta (see below).

Variation

There is considerable variation in Sonor cincta squamation, summarized in Holm (2008). Individuals can be either uniform or with red or orange and black or brown crossbands. Bands can take the form of complete bands that reach the ventral scales, saddles that reach the lateral dorsal surface, or dorsal spots. There is also variation in presence of a dark black cap on the head.

Distribution

Sonora cincta is distributed in the Sonoran desert and dry forests of southern Arizona, western Sonora south to Sinaloa and on the northern Baja California Peninsula at least as far south as Bahia Concepcion . They can be found from sea level to 1000 m in elevation ( Figure 4 ).

Remarks

This species is in the subgenus Chilomeniscus along with S. fasciata and S. straminea .

Figures

Figure 4. Map of the geographic distribution from IUCN and georeferenced occurrence records from GBIF (grey crosses) for the subgenus Chilomeniscus, including Sonora cincta, S. fasciata and S. straminea. The top of the map has images of the banded (a) morph of S. cincta. The side panel (b) depicts S. straminea. The bottom panel depicts the banded (c) morph of S. fasciata. Photos by C. L. Cox (a) and J. A. McGuire (b, c). Colours of shaded ranges and circular points on the map correspond to the phylogenetic tree in Figures 1 and 2.