Tsingymantis, Glaw, Frank, Hoegg, Simone & Vences, Miguel, 2006

Glaw, Frank, Hoegg, Simone & Vences, Miguel, 2006, Discovery of a new basal relict lineage of Madagascan frogs and its implications for mantellid evolution, Zootaxa 1334, pp. 27-43 : 30-31

Tsingymantis gen. nov.

Type species and only included species. Tsingymantis antitra sp. nov.

Etymology. Derived from "tsingy", the Malagasy word for eroded karstic limestone formations and the Greek word mantis = treefrog (see Vences et al. 1999 for the derivation of mantis). The genus name refers to the habitat, the tsingy formations of Ankarana. The gender of this genus is masculine.

Diagnosis. Large-sized species (female snout-vent length 66–67 mm) with a large tympanum (66–76% of eye diameter), toe 5>3, males unknown. Relatively little webbing between toes. No webbing between fingers. Lateral metatarsalia largely connected. Inner metatarsal tubercle very distinct, outer metatarsal tubercle absent. Finger tips strongly enlarged. Finger and toe pads with a complete circummarginal groove. First finger slightly shorter than second finger. Tibiotarsal articulation reaches the eye when the hind limb is adpressed along the body. Femoral glands not recognizable in females from external view. Tibial glands absent. Tongue bifid. For osteological characters see below. Habits terrestrial in tsingy formations. Activity nocturnal. Eggs pigmented (verified by dissection).

Tsingymantis gen. nov. does not show closer overall similarity to any other mantellid genus or species. Despite the absence of data on males, sexual dimorphism, and reproductive mode, there are still sufficient external characters to distinguish Tsingymantis from all other mantellid genera: Tsingymantis differs from the genus Boophis by a forked omosternum, largely connected metatarsalia, less webbing between toes and by general dissimilarity with any Boophis species; from Aglyptodactylus and Laliostoma by distinctly enlarged tips of fingers and toes, by the presence of a complete circummarginal groove on pads of fingers and toes, and by having the first finger shorter than the second; from Mantella (SVL 18–31 mm) and Wakea (SVL 11–16 mm) by much larger size, presence of maxillary teeth, and distinctly enlarged terminal finger disks; from Boehmantis and Mantidactylus sensu Glaw & Vences (2006) , including the subgenera Brygoomantis, Chonomantis, Hylobatrachus , Maitsomantis , Mantidactylus , and Ochthomantis , by largely connected metatarsalia and in addition from most of these species by the absence of femoral glands in females and by less developed webbing between toes; from Blommersia (SVL 15–27 mm, tympanum/eye 35–55 %) by much larger size and larger relative tympanum size; from all Guibemantis (tympanum/eye up to 64 %) by larger relative tympanum size, furthermore from the subgenus Guibemantis by largely connected metatarsalia and less webbing between the toes, and from the subgenus Pandanusicola (SVL 22–38 mm) by much larger size and very different habits; from Spinomantis (SVL 22–60 mm, tympanum/eye 33–60 %) by larger body size and larger relative tympanum size; and from all Gephyromantis (SVL 20–50 mm, tympanum/eye 30–67 %), including the subgenera Duboimantis , Gephyromantis , Laurentomantis , Phylacomantis , and Vatomantis by larger size and a relatively larger tympanum. In addition, Tsingymantis differs from most mantelline species by the following characters: bony part of the sternum longer than that of the omosternum, outer metatarsal tubercle absent, and toe 5 clearly longer than toe 3 (see Glaw & Vences 1994: 122–125). Tsingymantis is the only clade in the subfamily Mantellinae that is unknown from the rain forest areas (including the central high plateau) of Madagascar (where almost all mantelline species occur, except Mantella expectata , M. viridis , and Gephyromantis corvus ) and is only known from a very seasonal and moderately dry habitat.

Justification. All hitherto known mantellid clades, including 164 described and many undescribed species, can all clearly be assigned to one of the three subfamilies Mantellinae , Laliostominae , or Boophinae based on their sequences of mitochondrial and nuclear genes, and strongly supported by high bootstrap values (see below and unpublished data). A clear attribution of all mantellid lineages to one of these three subfamilies is also possible based solely on morphological data (see Glaw & Vences 2006). In contrast, the phylogenetic position of Tsingymantis antitra gen. nov. sp. nov. is not significantly resolved by the molecular ( Fig. 3 ) and morphological data although a basal sister group relationships to all other mantellines is indicated by the available overall evidence, and we propose preliminary inclusion of the new genus in the subfamily Mantellinae . Regarding this highly isolated position, the justification of the new genus is evident, but the possibility that future studies will reveal that Tsingymantis represents a fourth major lineage (subfamily) of the Mantellidae cannot be ruled out at present.

Figures

FIGURE 3. Phylogenetic tree of mantellids obtained by Bayesian Inference, based on 2303 nucleotide positions of four mitochondrial genes and one nuclear gene. Asterisks above branches indicate posterior probabilities (** = 100, * = 95 – 99). Values below branches are Maximum Likelihood bootstrap values.