Various life history stages of <i>Frankixalus jerdonii</i>.

<p>(A) lateral, (B) dorsal, (C) ventral views of a preserved stage 36 tadpole, (D) unfertilised “nutritive” eggs found inside the dissected larval gut (mean diameter = 1.0 mm), (E) oral disc with papillae demarcating its margins, shown in frontal view of a stage 36 tadpole, (F) dextral vent tube, in ventral view of a stage 26 tadpole, (G) sinistral spiracular tube, in ventral view of a stage 36 tadpole, (H) gel-encapsulated eggs (mean diameter = 2.0 mm) found on the inside wall of a tree hole, (I) dorsolateral view of a stage 44 tadpole, (J) oral disc of a live stage 36 tadpole having a bifurcated muscular tongue, shown in frontal view, (K) dorsal, (L) ventral views of a live stage 35 tadpole, (M) serrated, inverted upper jaw of a stage 37 tadpole in ventral view, (N) serrated, V-shaped lower jaw of a stage 37 tadpole in ventral view.</p

Comparison of osteological characters of four closely-related generic type species: <i>Gracixalus gracilipes</i> (AMNH A163893, an adult female, SVL 29.6 mm, from Vietnam), <i>Frankixalus jerdonii</i> (SDBDU 2009.1163, an adult male, SVL 41.6 mm, from Mawphlang), <i>Kurixalus eiffengeri</i> (AMNH A14498, an adult female, SVL 33.0 mm, from Taiwan) and <i>Philautus aurifasciatus</i> (AMNH A24559, an adult female, SVL 22.2 mm, from Indonesia).

<p>(A) shape of the premaxillae, (B) shape and development of frontoparietals, (C) structure of vomers, (D) ossified elements and shape of the pectoral girdles, (E) anatomy of the carpal elements. Abbreviations: FP, frontoparietal; OS, omosternum; PM, premaxilla; PP, prepollex; SP, sphenethmoid; ST, sternum; VM, vomer. All scale bars represent 2 mm.</p

A–C, <i>Frankixalus jerdonii</i> in life.

<p>(A) dorsolateral view of an adult male (BNHS 5976), (B) an adult male (SDBDU 2009.271) emerging from a tree hole, (C) frontal view of an adult male (BNHS 5977). D–H, A composite showing the breeding habitat of <i>Frankixalus jerdonii</i>. (D) Evergreen forest at Mawphlang in East Khasi Hills district of Meghalaya state, (E) close-up of a tree hole opening located 3.4 meters above the ground, (F) oviposition site with eggs adhered to the inner vertical walls of the tree hole above the water level, and arrow pointing towards an adult female found submerged about 1 cm below the water surface, (G) unpigmented gel-encapsulated eggs, (H) premetamorphic larva inside the water-filled tree hole.</p

<i>Frankixalus</i>, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles

<div><p>Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as <i>Frankixalus</i><b>gen. nov.</b> This genus, which contains the enigmatic ‘<i>Polypedates</i>’ <i>jerdonii</i> described by Günther in 1876, forms the sister group of a clade containing <i>Kurixalus</i>, <i>Pseudophilautus</i>, <i>Raorchestes</i>, <i>Mercurana</i> and <i>Beddomixalus</i>. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.</p></div

Geographic distribution of <i>Frankixalus</i> in Northeast India and China.

<p>Circle = <i>Frankixalus jerdonii</i>, square = <i>Frankixalus</i> sp.</p

Bayesian consensus phylogram showing phylogenetic relationships among 86 taxa representing all known rhacophorid genera and one outgroup species.

<p>Numbers above the branches represent Bayesian Posterior Probabilities, numbers below the branches represent Maximum Likelihood bootstrap values. Clade representing <i>Frankixalus</i> gen. nov. is shown in red. The specimen that was assigned to “<i>Theloderma moloch</i>” by Li <i>et al</i>. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145727#pone.0145727.ref053" target="_blank">53</a>] is indicated by an asterisk. Colors of taxa labels represent the reproductive modes: blue, terrestrial foam-nesting, exotrophic tadpoles; orange, terrestrial gel-nesting, exotrophic tadpoles; green, terrestrial direct-developing, endotrophic tadpoles; cyan, aquatic gel-nesting, exotrophic tadpoles. The new genus <i>Frankixalus</i> is also a terrestrial gel-nesting form.</p