Tytthoscincus, Linkem & Diesmos & Brown, 2011

Linkem, Charles W., Diesmos, Arvin C. & Brown, Rafe M., 2011, Molecular systematics of the Philippine forest skinks (Squamata: Scincidae: Sphenomorphus): testing morphological hypotheses of interspecific relationships, Zoological Journal of the Linnean Society 163 (4), pp. 1217-1243 : 1232

Tytthoscincus gen. nov.

Type species: Tytthoscincus hallieri (Lidth de Jeude, 1905) .

Definition: The clade comprising Tytthoscincus hallieri (Lidth de Juede, 1905) and all species that share a more recent common ancestor with Tytthoscincus hallieri than with Anomalopus verreauxii , Calyptotis scutirostrum , Coeranoscincus frontalis , Coggeria naufragus , Ctenotus taeniolatus , Eremiascincus richardsonii , Eulamprus quoyiii , Glaphyromorphus isolepis , Gnypetoscincus queenslandiae , Hemiergis decresiensis , Insulasaurus wrighti , Lerista lineata , Lipinia pulchella , Nangura spinosa , Notoscincus ornatus , Ophioscincus australis , Otosaurus cumingi , Papuascincus stanleyanus , Parvoscincus sisoni , Pinoyscincus jagori , Prasinohaema flavipes , Saiphos equalis , Scincella lateralis , and Sphenomorphus melanopogon .

Etymology: From the Greek tytthos, meaning ‘small’ and the Latin scincus for lizard; the combination refers to the small sizes of the species in this genus. Suggested common name: diminutive Asian skink.

Description: Tytthoscincus can be identified by the following characters: (1) body size diminutive, usually less than 45 mm SVL; (2) temporal scales small, same size and shape as lateral body scales ( Fig. 5 ); and (3) digits small, toe IV slightly longer than, or equal to, toe III.

Included species: Tytthoscincus aesculeticolus ( Inger et al., 2001) , Tytthoscincus atrigularis (Stejneger, 1905) , Tytthoscincus biparietalis (Taylor, 1918) , Tytthoscincus hallieri (Lidth de Juede, 1905) , and Tytthoscincus parvus ( Boulenger, 1897) .

Comment: This clade of diminutive species has unique features that diagnoses it from all other skinks of the Sphenomorphus group. Although we lack genetic data for Tytthoscincus biparentialis , we nonetheless include it in this genus because it shares the unique presence of divided parietal scales with Tytthoscincus hallieri . The diminutive skinks of Malaysia ( Grismer, Ahmad & Onn, 2009) should probably also be placed in this new genus, although we prefer to leave that decision in abeyance until a morphological and genetic examination of those taxa are complete. Tytthoscincus parvus ( Boulenger, 1897) is one of three species of diminutive skinks described from Sulawesi Island. It is likely that the other diminutive species on Sulawesi, Sphenomorphus temmincki and Sphenomorphus textus are also part of Tytthoscincus . Future examination of temporal scales on small skinks in South-East Asia should reveal the species composition of Tytthoscincus .

Figures

Figure 5. Lateral view of the heads of Tytthoscincus hallieri (A, redrawn from Inger et al., 2001: fig. 4) and of Parvoscincus cf. decipiens 1 (B). The temporal scales (highlighted in grey) of the new genus Tytthoscincus are small and blend in with the body scales, which is different from the typical shield-like temporal scales (B).