Synophis calamitus Hillis, 1990

Pyron, R. Alexander, Arteaga, Alejandro, Echevarría, Lourdes Y. & Torres-Carvajal, Omar, 2016, A revision and key for the tribe Diaphorolepidini (Serpentes: Dipsadidae) and checklist for the genus Synophis, Zootaxa 4171 (2), pp. 293-320 : 307

4. Synophis calamitus Hillis, 1990

Range. Pacific Andean slopes of central and northern Ecuador, primarily in Pichincha, Santo Domingo de los Tsáchilas, and Cotopaxi provinces, ~ 1000–2300m . Populations also occur in Carchi province (~ 1900m), and possibly Chimborazo province (~ 800m; see below).

Description. Adult size ~ 330–510mm SVL and ~ 190–280mm TL (assuming> 330mm SVL is adult), smooth nuchal scales; no nuchal collar; intranasals usually in contact but occasionally divided by rostral; usually 2 postoculars but occasionally 0 or 1; 8–11 infralabials; 7–9 supralabials; 157–166 ventrals; 96–125 subcaudals including possibly truncated tails, 100–113 in females, 109–118 in males; and (19–23)-19-17 dorsal scale-rows with single, weak keel.

Notes. Includes a much larger range of specimens identified as Synophis aff. bicolor from the western Andes by Pyron et al. (2015). The specimen from Carchi province in northern Ecuador (QCAZ5847) is morphologically identical to other S. calamitus populations ( Torres-Carvajal et al. 2015), but genetically distinct from the central Ecuadorean populations ( Figs. 1 , 4 ). There is thus intraspecific genetic diversity in S. calamitus , possibly related to the Río Mira as a geographic barrier to gene flow. The southernmost specimen, from Chimborazo province (CAS23612; Fig. 4 ), resembles both S. calamitus and S. zaheri . We refer it here to S. calamitus , for which it is a southern range extension, but it may represent a northern range extension for S. zaheri or a new species. Collecting effort in this locality should be a priority.

Figures

FIGURE 1. Bayesian maximum clade credibility phylogeny for Diaphorolepidini, summarized from 15 million post-burnin generations in MrBayes 3.2. 5. Support values> 50 % are shown. Clades of primarily North American (NA), Central American (CA), and South American (SA) species other than Diaphorolepidini are collapsed.

FIGURE 4. Map of verified localities for the 9 known, extant species of Synophis. Circles are colored by species: S. niceforomariae (purple), S. lasallei (yellow), S. plectovertebralis (black), S. bicolor (green), S. calamitus (teal), S. bogerti (orange), S. zamora (pink), S. zaheri (red), and S. insulomontanus (blue).