Sonora taylori (BOULENGER, 1894)
Can you confirm these amateur observations of Sonora taylori?
|Higher Taxa||Colubridae, Colubrinae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Taylor’s Ground Snake|
S: Culebrilla de Taylor
|Synonym||Contia taylori BOULENGER 1894|
Chionactis taylorii — COPE 1900: 936
Sonora taylori — STEJNEGER & BARBOUR 1917: 92
Sonora taylori — STICKEL 1938: 184
Sonora taylori — STICKEL 1943
Sonora taylori — SMITH & TAYLOR 1945
Sonora semiannulata taylori — FROST & VAN DEVENDER 1979: 6
Sonora semiannulata — FROST 1983: 333.1
Sonora semiannulata taylori — DIXON 2000
Sonora semiannulata taylori — CROTHER et al. 2012
Sonora (Sonora) taylori — COX et al. 2018: 970
|Distribution||USA (S Texas), Mexico (Tamaulipas ?)|
Type locality: Duval Co., Texas, and Nuevo Leon, Mexico, restricted to Duval County, Texas by Stickel 1943.
|Types||Syntypes: BMNH 1918.104.22.168–1922.214.171.124|
|Diagnosis||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. Sonora taylori can be potentially confused only with S. episcopa, with which it is either sympatric or narrowly allopatric. The S. semiannulata species group has been historically difficult to define using morphological characteristics, and in fact it was this lack of clear colour pattern or meristic characters delimiting species that led Frost and VanDevender (1979) to synonymize many different species and subspecies into S. semiannulata. However, our genetic data show clear reciprocal monophyly of S. episcopa and S. taylori. Perhaps the best way to distinguish S. episcopa from S. taylori is by geographic range (see below). Besides geographic range, Dixon and Werler (2005) suggest that S. taylori can be distinguished from S. episcopa based upon the presence of 13 midbody scale rows (compared to 14 or 15 in S. episcopa) (Cox et al. 2018: 970).|
Variation: Sonora taylori is one of only three species in the genus that do not have bands or stripes, and so lack polymorphism and coral snake mimicry. This uniformly brown snake has some slight variation in ground colour from grey to tan, buff or brown, and Dixon and Werler (2005) have noted that the maculated scales often give the impression of light longitudinal lines. In addition, this species does have polymorphism for the black cap on the head (Figure 3 in Cox et al. 2018: 970).
|Comment||Distribution: Not in Nuevo León fide Nevárez-de los Reyes et al. 2016 (who consider it as part of S. semiannulata). Specimens from Tamaulipas may be S. taylori but Cox et al. 2018 did not have any DNa samples from that state so they state that the occurrence there has not been confirmed.|
Synonymy: Frost 1983 and Wallach et al. 2014: 681 listed this species as synonym of S. semiannulata.
|Etymology||A patronimic after W. Taylor. It is likely to correspond to a William Taylor from the British Museum, collector of the type specimens.|