Sonora punctatissima, (Van Denburgh and Slevin 1921)

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 : 972-973

Sonora punctatissima ( Van Denburgh and Slevin 1921)

Chilomeniscus punctatissimus van Denburgh and Slevin 1921:98 . Holotype: The holotype is the California Academy of Sciences (CAS 49156). Type locality: The type locality is listed as ‘ Isla Partida , Espiritu Santo Island , Gulf of California, Mexico’ , suggesting a type locality of Partida Island .

Chilomeniscus punctatissimus Banta and Leviton 1963:322

Chilomeniscus stramineus Grismer et al. 2002:28

Chilomeniscus punctatissimus Holm 2008:34

Diagnosis

Sonora punctatissima can be distinguished from all other Sonora except for S. fasciata , S. cincta , S. stramineus and S. savagei by the presence of an elongated rostrum. Perhaps the best way to distinguish S. punctatissima from S. fasciata , S. cincta , S. stramineus and S. savagei is by geographic location; S. punctatissima is the only member of the genus Sonora on Partida and Espiritu Santo Islands. However, S. punctatissima can be distinguished from S. stramineus by lacking apical maculations on dorsal body scales ( Holm 2008), although Grismer et al. (2002) noted the presence of blotches on scales of some morphs. Sonora punctatissima can be distinguished from S. savagei by having less than 127 ventral scales, compared to greater than 127 for S. savagei ( Holm 2008) . Sonora punctatissima can be distinguished from S. fasciata and S. cincta by either a gap between the internasals, possessing less than 35 bands and variation in ventral and subcaudal scale numbers summarized in Holm (2008).

Variation

This is a variable species, especially given the limited geographic range, with Grismer et al. (2002) describing four main pattern classes and individuals with intermediate pattern types. This species can be banded or unbanded, and the expression of bands in the banded individuals varies between a clearly demarcated black bands to grey or brown bands with indistinct margins.

Distribution

Sonora punctatissima is only known from Partida and Santu Espirito Islands off of the south-eastern coast of Baja California Sur .

Remarks

Sonora punctatissima is recognized based upon clear scutellation differences from other members of the subgenus Chilomeniscus , but we did not have access to tissue samples for this study. Future research that provides genetic samples of S. punctatissima can confirm the phylogenetic position of this species.