Magliophis Zaher et al., 2009

Hedges, Blair, Couloux, Arnaud & Vidal, Nicolas, 2009, Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae), Zootaxa 2067, pp. 1-28 : 19

Genus Magliophis Zaher et al., 2009

Type species. Dromicus exiguus Cope, 1862 [1863]:79.

Diagnosis. Species in this genus have 19 midbody scale rows, 137–165 ventrals, 71–102 subcaudals, no apical scale pits, eight upper labials, and nine lower labials ( Table 2). Magliophis differs from each of the other alsophiine genera in at least one of those characters.

Content. Two species (three species + subspecies) are included in the genus ( Table 1).

Distribution. Species of Magliophis are distributed throughout the Puerto Rican Bank ( Fig. 2 ).

Remarks. Species of Magliophis ( Fig. 3 F) are small racers (438 mm, maximum snout-vent length, SVL) that occur sympatrically with the larger racers of the Genus Borikenophis on the Puerto Rican Bank. The two included species were previously placed in the Genus Arrhyton . The phylogenetic trees ( Figs. 1 and 4 ) show that Magliophis stahli is quite divergent from M. exiguus , which agrees with morphology ( Schwartz 1967) and supports its recognition as a distinct species rather than subspecies. Zaher et al. (2009) described this genus based on hemipenial characters in the species M. exiguus . Oddly, that species was omitted from their molecular phylogeny even though it was present in the data set of Vidal et al (2000), and corresponding sequences were available in GenBank.

Figures

FIGURE 2. Map showing the West Indies (including the southern tip of Florida above, Central America to the west, and the northern edge of South America below) and the distributions of the genera of the Tribe Alsophiini, Subfamily Xenodontinae, Family Dipsadidae.

FIGURE 3. Representatives of genera of the snake Tribe Alsophiini (Dipsadidae: Xenonodontinae). Subtribe Alsophiina: Alsophis manselli (Woodlands Spring, Montserrat), Borikenophis portoricensis (1.5 km W. Playa de Tamarindo, Puerto Rico), Cubophis cantherigerus (2.0 km W Viñales, Pinar del Rio, Cuba), Hypsirhynchus ferox (Barahona, Barahona, Dominican Republic), Ialtris dorsalis (3 km N Bois Sec, Grand’Anse, Haiti), and Magliophis stahli (1.9 km NE Vista Alegre, Puerto Rico). Subtribe Arrhytonina: Arrhyton taeniatum (0.2 km WE Windmill Beach, Guantanamo Bay Naval Station, Cuba). Subtribe Uromacerina: Uromacer oxyrhynchus (4.4 km W Canada Honda, La Altagracia, Dominican Republic). Photos by S. B. Hedges.

FIGURE 1. A phylogeny of Alsophiini. Bayesian tree obtained from the combined data set of six genes (RAG 2, 12 S & 16 S rRNA, cytochrome b, ND 2 and ND 4; 3387 sites). Alsophis portoricensis portoricensis and A. p. anegadae have identical sequences at all genes sampled, and therefore the latter taxon is not shown. Values are ML bootstrap values above 70 % followed by Bayesian posterior probabilities above 90 %. The generic taxonomy in this tree reflects usage prior to this study and shows paraphyly and polyphyly of Alsophis (blue), Arrhyton (purple), and Antillophis (orange). See Table 1 and Figure 4 for the new classification proposed here.

FIGURE 4. A timetree of Alsophiini. Divergence times and credibility / confidence intervals are shown in Table 3. Plei = Pleistocene. The generic taxonomy in this tree reflects the new classification proposed here and detailed in Table 1.