Scolecophis mosaueri, Stickel 1938

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 : 982-983

Sonora mosaueri Stickel 1938

Sonora mosaueri Stickel 1938:187 . Holotype: The holotype is in the Museum of Vertebrate Zoology (MVZ 13772) with paratypes MVZ 13770–71 and 13773. Type locality: Comondu , Baja California Sur.

Sonora semiannulata Frost 1983a:35–36

Diagnosis

This species is distinct from Sonora cincta , S. fasciata , S. straminea , S. aemula , S. annulata , S. occipitalis and S. palarostris by the lack of rostral or caudal adaptations. There are no clear morphological differences between S. mosaueri and S. semiannualata , whose geographic ranges may overlap in the northern state of Baja California. This lack of meristic characters distinguishing the various species and subspecies of the S. semiannulata species group is what led Frost (1983a) to synonymize all of these nomen with S. semiannulata . However, we found substantial molecular evidence that material formerly assigned to S. semiannulata from the southern half of the Baja California Peninsula is not even nested with S. semiannulata from the USA and northern mainland Mexico, but is instead sister to S. aemula . We recommend that geographic range be used to distinguish S. mosaueri from S. semiannulata (see below).

Variation

Sonora mosaueri is not polymorphic, and all individuals are brown, grey, or tan uniform in appearance. Individuals of this species often have prominent maculations on the dorsal scales, and have the largest body size of the S. semiannulata species group.

Distribution

The complete geographic range of S. mosaueri is unclear, given the general paucity of specimens and tissues for genetic analysis. The description of this taxon only included animals in the type series from near Comondu, although Stickel (1938) speculates that other specimens from near Santa Rosalia could also be assigned to S. mosaueri . Our genetic work has revealed that S. mosaueri extends at least as far north as San Ignacio (Mulege Municipality), and as far south as near La Paz, Baja California Sur ( Figure 7 ). It is likely that S. mosaueri extends to the southern tip of Baja California Sur, but its northern limit is unknown.

Remarks

Future work should attempt to acquire material from north of San Ignacio, to clarify the contact zone between Sonora semiannulata and S. mosaueri and assess the validity of S. semiannulata bancroftae . In addition, because S. mosaueri is more closely related to S. aemula than other material formerly assigned to S. semiannulata , the presence and extent of sympatry with S. semiannulata could be revealed by focused sampling in northern Baja California. This species is part of the subgenus Procinura with S. aemula .

Figures

Figure 7. Map of the geographic distribution from IUCN and georeferenced occurrence records from GBIF (grey crosses) for the subgenus Procinura, including Sonora mosaueri and S. aemula. The top of the map has images of the S. mosaueri (a) and the tricolour (b and c) and uniform (d) morphs of S. aemula. Photos by C. L. Cox (a), C. Rodriguez (b), and C. M. Bogert (c, d). Colours of shaded ranges and circular points on the map correspond to the phylogenetic tree in Figures 1 and 2.