Indorana prasadi, Folie & Rana & Rose & Sahni & Kumar & Singh & Smith, 2013
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publication ID |
https://doi.org/ 10.4202/app.2011.0063 |
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persistent identifier |
https://treatment.plazi.org/id/03D287C7-8355-FFD0-BCAE-C0E2FC33F9C9 |
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treatment provided by |
Felipe |
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scientific name |
Indorana prasadi |
| status |
sp. nov. |
Indorana prasadi sp. nov.
Fig. 9 View Fig .
Etymology: For Indian paleontologist Guntupalli V.R. Prasad, for his contributions to the knowledge of Indian frogs.
Holotype: GU/RSR/VAS 5220 ( Fig. 9A View Fig ), a nearly complete left ilium associated with the two ischia and pubis.
Type locality: Vastan Lignite Mine, Surat District, Gujarat, India.
Type horizon: Cambay Shale Formation, middle Ypresian, lower Eocene.
Referred material.—GU/RSR/VAS 5219 ( Fig. 9B View Fig ), an incomplete left ilium associated with the pubis, left ischium and half of the right ischium.
Diagnosis.—Ilium differs from Rhacophorus and Polypedates by a very weak dorsal crest on the iliac shaft, and from Buergeria buergeri in having an ossified pubis fused with the ilium and ischium, a wider acetabulum and a thicker iliac shaft.
Description.—In lateral view, the iliac shaft is almost straight and bears a weakly developed elongated tuber superius ( Fig. 9A View Fig 1 View Fig ). The acetabular area is relatively large dorsoventrally in comparison with the shaft. There is no subacetabular or supraacetabular fossa. The angle between the tuber superius and the pars ascendens is close to 180°, whereas the angle between the shaft and pars descendens is close to 90°. The pars ascendens is short. The extremity of the pars descendens is flared. The acetabulum is deep, slightly bell−shaped, and has a sharp rim. A shallow groove extends from the tuber superius to the anteroventral part of the shaft. The suture with the ischium is nearly dorsoventrally oriented. An ossified pubis is fused with
http://dx.doi.org/10.4202/app.2011.0063
the ilium and ischium but its limits are not readily visible. The ischium is reniform and its dorsal border is laterally thickened. The acetabulum is deep and presents a rim as sharp as on the ilium. On its posterior border, the ischium bears a tubercle that projects laterally. This structure is clearly visible in posterior view ( Fig. 9A View Fig 2, B 2 View Fig ). In medial view, there is no ornamentation (e.g., striae or foramina) on the ilium except for a weak dorsal crest ( Fig. 9A View Fig 3 View Fig , A 4 View Fig , B 3 View Fig , B 4 View Fig ). The latter begins on the dorsal part of the shaft, close to the tuber superius, and extends on the medial side of the shaft. There is no interiliac tubercle. In dorsal view, the iliac shaft is slightly laterally compressed, and the tuber superius, and the dorsal crest project laterally, and medially, respectively ( Fig. 9A View Fig 3 View Fig , A 4 View Fig , B 3 View Fig , B 4 View Fig ; see Table 1).
Discussion.—This specimen presents features that differ from those of most major groups of frogs. A weak or low dorsal crest is present in some non−ranoid frogs such as Hylidae and Leptodactylidae ( Lynch 1971; Holman 2003). However, both families differ from the Vastan taxon by a more developed and globular tuber superius ( Bailon 1999).
This taxon does not belong to “ Ranidae ” or Discoglossidae of the “ Discoglossus group” because the dorsal crest of the iliac shaft is less developed in particular in the posterior area of the ilium ( Rage and Hossini 2000). It most resembles Rhacophoridae (which is here considered a family of the superfamily Ranoidea, sensu Cannatella 2007 ) in having a weakly developed tuber superius and a relatively elongate pars descendens ( Nokariya 1983b: fig. 4.5). The laterally projecting tubercle on the posterior border of the ischium is another character shared with rhacophorids, such as several species of Rhacophorus ( Nokariya 1983b) and the species Polypedates leucomystax (MNHN n°1871–187, Recent, Philippines). Moreover, it resembles the species Buergeria buergeri (previously referred to Rhacophorus ) in having a weak dorsal crest and the anterior border of the acetabulum that extends to half the length of the tuber superius. However, the pubis of the Vastan specimen is better developed. Indeed, based on Nokariya (1983b: fig. 4.5), the pubis of B. buergeri is cartilaginous, whereas it is ossified and fused with the ilium and the ischium in the Vastan taxon. Moreover, the acetabulum is wider, and the shaft is thicker than in B. buergeri . These morphological differences and the temporal gap between extant B. buergeri and the Vastan form allow us to erect the new name Indorana prasadi , gen. and sp. nov., for this early Eocene frog and to tentatively attribute it to the family Rhacophoridae .
Liem (1970) considered the genus Buergeria as a primitive rhacophorid frog because it presents several putative plesiomorphies among Asiatic rhacophorids, such as the presence of musculus adductor longus, an arch−shaped anterior horn of the hyoid, and the presence of second and fourth phalangeal slips of the musculus humerodorsalis. Subsequently, Channig (1989) erected the subfamily Buergeriinae for this genus, restricted to Taiwan and Japan, indicating that it is the sister taxon of the other Rhacophoridae . These data are in agreement with the possibility that Indorana prasadi represents a primitive rhacophorid.
Stratigraphic and geographic range.— Type locality and horizon only.
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