A new genus for the Rhamphotyphlops subocularis species group (Serpentes: Typhlopidae), with description of a new species

I June 1995 Asiatic Herpetological Research Vol. 6, pp. 132-150 A New Genus for the Ramphotyphlops subocularis Species Group (Serpentes: Typhlopidae), with Description of a New Species VAN WALLACH Center for Vertebrate Studies, Department of Biology, Northeastern University, Boston, MA 02115, USA Abstract. — A new genus, Acutotyphlops, is established for McDowell's Ramphotvphlops subocularis species group (minus R. willeyi which is transferred to the R.flaviventer group) based on a parietal bone projection, head shield fragmentation, and a V-shaped lower jaw. Two species are revalidated, A. infralabialis and A. solomonis, and a new species is described from Bougainville Island, A. kunuaensis. Acutotyphlops kunuaensis, represented by more than 250 specimens, is distributed throughout Bougainville, both in the coastal lowlands and the interior highlands. Sexual dimorphism is present in certain scutellation and proportional characters. At least five species of typhlopids are now known to inhabit Bougainville Island. Key words: Ramphotyphlops subocularis group, Acutotyphlops, A. kunuaensis, A. subocularis, A. infralabialis, A. solomonis, Typhlops adamsi, T. bergi, Papua New Guinea, Bougainville Introduction McCoy (1970), McDowell (1974), and Hahn (1980) listed three species of Typhlina (= Ramphotyphlops) inhabiting Bougainville Island in the Solomons: Ramphotyphlops braminus, R.flaviventer (= R. depressus fide Wallach, in prep.), and R. subocularis. In his thorough review of the typhlopids of New Guinea and the Solomon Islands, McDowell (1974) defined the Ramphotyphlops subocularis species group as lacking a rectal caecum and exhibiting a wedge-shaped lateral snout profile. He recognized two species in the group, Ramphotyphlops subocularis (Waite, 1897) and R. willeyi (Boulenger, 1900), considering the latter to be the most primitive member, scarcely differing from R. flaviv enter (Peters, 1864) of the Ramphotyphlops flaviventer species group except in the wedge-shaped snout and absence of a caecum. Ramphotyphlops subocularis was described as differing from R. willeyi in the more specialized fragmentation of the lateral head shields (multiple preoculars and suboculars vs. a single preocular and no subocular), increased number of midbody scale rows (26-36 vs. 20-22), and the acute mandibular symphysis (V-shaped vs. U-shaped). Ramphotyphlops willeyi also differs from R . subocularis in the presence of a unicameral right lung (vs. multicameral), a convoluted and multisegmented liver (vs. straight and unsegmented), and absence of frontorostral and paired prefrontals on the dorsum of the head (pers. obs.). McDowell (1974) placed five nominal taxa in the synonymy of Ramphotyphlops subocularis, stating that the number of valid species remained to be determined but based upon published data there was no evidence to suggest that more than one variable species was involved. The taxa synonymized with R. subocularis were Typhlops infralabialis Waite, 1918, Typhlops solomonis Parker, 1939, Typhlops bergi Peters, 1948, Typhlops keasti Kinghorn, 1948, and Typhlops adamsi Tanner, 1951 (see McDowell, 1974, for complete synonymy). An examination of the types of all of the above taxa, plus the majority of Ramphotyphlops subocularis material in museum collections indicates that the R. subocularis complex consists of at least four valid species (R. subocularis, R. infralabialis, R . solomonis, and an undescribed species that forms the topic of this paper). A description of the cranial osteology, internal anatomy, and geographic variation in the Ramphotyphlops subocularis group, with emphasis on the new species, will be the subject of a future paper (Wallach, Wong and Meszoely, in prep). Methods All traceable museum specimens of the Ramphotyphlops subocularis group (> 325 specimens) were examined, including the © 1995 by Asiatic Herpetological Research

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A new genus for the Rhamphotyphlops subocularis species group (Serpentes: Typhlopidae), with description of a new species

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