Typhlops Oppel, 1811

Pyron, Robert Alexander & Wallach, Van, 2014, Systematics of the blindsnakes (Serpentes: Scolecophidia: Typhlopoidea) based on molecular and morphological evidence, Zootaxa 3829 (1), pp. 1-81 : 46

Typhlops Oppel, 1811

Type species. Anguis lumbricalis Linnaeus, 1758

Species content. Typhlops agoralionis , T. anchaurus , T. annae , T. anousius , T. arator , T. biminiensis , T. capitulatus , T. catapontus , T. caymanensis , T. coecatus (?), T. contorhinus , T. dominicanus , T. epactius , T. eperopeus , T. geotomus , T. golyathi , T. gonavensis , T. granti , T. guadeloupensis , T. hectus , T. hypomethes , T. jamaicensis , T. leptolepis , T. lumbricalis , T. monastus , T. monensis , T. naugus , T. notorachius , T. oxyrhinus , T. pachyrhinus , T. paradoxus , T. perimychus , T. platycephalus , T. proancylops , T. pusillus , T. richardii , T. rostellatus , T. satelles , T. schwartzi , T. silus , T. sulcatus , T. sylleptor , T. syntherus , T. tetrathyreus , T. titanops , and T. zenkeri (?).

Diagnosis. Typhlops can be distinguished from all other typhlopoids by its subtriangular preocular with an anterior extension that is only in contact with the third supralabial. Small- to large-sized (total length 70–460 mm), stout- to slender-bodied (length/width ratio 23–78 but average 30–50) snakes with 16–24 scale rows (with or without reduction), 231–629 total middorsals, short to long tail (0.9–5.6% total length) with 5–22 subcaudals (length/width ratio 0.8–3.2), and apical spine usually small and spike-like, occasionally thorn-like or even a reduced nubbin. Dorsal and lateral head profiles bluntly rounded or tapered, narrow to moderate oval, sagittate, parallel or waisted rostral (0.17–0.49 head width), preocular in contact with third supralabial, eye small to moderate, with or without a pupil, T-III SIP (T-0 in T. zenkeri , tentatively placed here), and postoculars 1–2. Lateral tongue papillae absent; left lung absent, tracheal lung, cardiac and right lungs usually multicameral (with 18–38 chambers and 1–7 pockets), but also paucicameral (with 1–33 pockets), and unicameral; testes unsegmented; hemipenis eversible, lacking retrocloacal sacs; rectal caecum usually small (0.6–4.0% SVL), and rarely absent. Coloration sometimes pink (pigmentless), but usually light or golden-brown to brown dorsally, fading to an immaculate golden-yellow venter, sometimes snout and cloacal region light.

Phylogenetic definition. Includes the MRCA of Typhlops lumbricalis and T. biminiensis and all descendants thereof, and all species more closely related to T. lumbricalis than to the type species of the 15 typhlopid genera listed here.

Etymology. From the Greek for blind (typhlos) and eye (ops).

Distribution. The West Indies (most species) and West Africa ( T. coecatus and T. zenkeri ).

Remarks. Note that Hedges et al. (2014) transferred two West African species ( Typhlops coecatus and T. zenkeri ) to Letheobia based on a nasal suture originating at the second labial and a subocular scale, respectively. However, these species appear to be strongly allied to Typhlops based on the preocular shape, 18–20 scale rows, narrow rostral, unicameral tracheal lung, T-III SIP in T. coecatus , and absence of rectal caecum in T. zenkeri (Table 2). Both West African species have a primitive unicameral lung system, as do several of the examined Caribbean Typhlops ( T. hectus , T. monensis , T. pusillus , and T. rostellatus ). In contrast, all Afrotyphlopinae have a multicameral tracheal lung, while the unicameral condition is only found in Gerrhopilus , Typhlops , and Indotyphlops (Table 2). Visceral anatomy also strongly links the species to Typhlops , being markedly different from Letheobia ( Table 4 ). Thus, we restore these species to Typhlops , giving that genus a small range in West Africa (Table 1, Fig. 1 ).

This genus includes the Caribbean Arc Radiation ( Dixon & Hendricks 1979) and the Major Antillean Radiation ( Thomas 1989), reclassified by Hedges et al. (2014) to place T. annae , T. catapontus , T. dominicanus , T. geotomus , T. granti , T. guadeloupensis , T. hypomethes , T. monastus , T. monensis , T. naugus , T. platycephalus , and T. richardi in Antillotyphlops , and T. anchaurus , T. anousius , T. arator , T. biminiensis , T. caymanensis , T. contorhinus , T. epactius , T. golyathi , T. notorachius , T. paradoxus , T. perimychus , and T. satelles in Cubatyphlops . However, the type species of Cubatyphlops ( C. biminiensis ) is strongly supported as the sister group to the remaining Cubatyphlops , Antillotyphlops , and Typhlops ( Fig. 1 ). Thus, we formally propose to synonymize Cubatyphlops and Antillotyphlops with Typhlops , as they also cannot be unambiguously diagnosed morphologically (Table 2). The only alternative would be to restrict Cubatyphlops to C. biminiensis , and erect another new genus for the remaining former species of Cubatyphlops . This group contains additional undescribed species ( Hedges et al. 2014).

Figures

FIGURE 1. Results from a molecular phylogenetic analysis of 95 of the 275 known, extant species of typhlopoid blindsnakes. Tree represents the ML estimate from a concatenated matrix of 4 mitochondrial and 6 nuclear genes (6290 bp total), inferred using 200 independent searches in RAxMLv 7.2.8, with support estimated from 1000 non-parametric BS replicates (> 50 % shown).