ANURA, Fischer von Waldheim, 1813

Lapparent, France de, Bailon, Salvador, Augé, Marc Louis & Rage, Jean-Claude, 2020, Amphibians and reptiles from the Neogene of Afghanistan, Geodiversitas 42 (22), pp. 409-426 : 411-412

ANURA indet. sp. A

LOCALITY AND AGE. — Sherullah 9, Khordkabul basin, Afghanistan, late Miocene, late Vallesian-basal Turolian transition, MN10/11.

MATERIAL EXAMINED. — Five fragments of toothed maxillae (AFG 1656), 1 fragment of angulosplenial (AFG 1657), 1 fragment of atlas (AFG 1658), 5 amphicoelous presacral vertebrae (AFG 1659), 7 non-amphicoelous presacral vertebrae (AFG 1660), 5 opisthocoelous sacral vertebrae (AFG 1661), 2 procoelous sacral vertebrae (AFG 1662), 5 fragments of urostyles (AFG 1663), 34 ilia (AFG 1664), 3 fragmentary humeri (AFG 1665), 3 fragments of radioulna (AFG 1666), 1 fragment of femur (AFG 1667).

DESCRIPTION AND COMMENTS

Only the maxillae, vertebrae and ilia deserve comments. The other remains provide no information. The presence of teeth on the maxillae allows to rule out Bufonidae , where these bones are toothless. The vertebrae are only represented by their centra. Five centra of presacral vertebrae are amphicoelous, deeply biconcave, whereas seven are non-amphicoelous (it is not possible to determine their condition, procoelous or opisthocoelous). Vertebrae of Alytidae are opisthocoelous. In “ Ranidae ”, the last presacral vertebra is amphicoelous whereas the seven others are procoelous. Consequently, within the set of presacral vertebrae from Sherullah 9, the ratio amphicoelous/ non-amphicoelous vertebrae is somewhat surprising. In a few anuran groups, all presacral vertebrae are amphicoelous: in the living Leiopelmatidae Mivart, 1869 ( New Zealand) and Ascaphidae Fejérváry, 1923 (Western North America) the centra are clearly amphicoelous; in the Megophryidae Bonaparte, 1850 (southern Asia) and various Myobatrachidae Schlegel, 1850 ( Australia) the intervertebral cartilages remain free in adults, therefore the vertebrae are amphicoelous but they are not deeply biconcave. Among extinct forms, Notobatrachus Reig, 1956 and likely Vieraella Reig, 1961 (both from the Jurassic of South America), as well as the Gobiatidae

Roček & Nessov 1993 (Cretaceous of Central Asia) are amphicoelous ( Báez &Basso 1996; Roček & Nessov1993).But, comparisons between “amphicoelous taxa” and amphicoelous vertebrae from Sherullah 9 cannot be made because the latter specimens are known only by their centra.Based on the available specimens from Sherullah 9 a family assignment is not possible.

Sacral vertebrae, as presacral ones, are represented by centra. The posterior face of all centra is bicondylar. But, in five sacral vertebrae the anterior face is convex (opisthocoelous) while it is concave (procoelous) in two specimens. The opisthocoelous sacral vertebrae may belong to Alytidae or “ Ranidae ”. But procoelous sacral vertebrae represent another family that cannot be identified.

All ilia have a dorsal crest. This morphological feature is present in Discoglossinae (Alytidae) , Pipidae Gray, 1825 , “ Ranidae ”, Rhacophoridae and various Leptodactylidae Werner, 1896 and Hylidae Rafinesque, 1815 . The morphology of the tuber superius and dorsal crest of the fossil leads to rule out Pipidae , Rhacophoridae , Leptodactylidae and Hylidae , but the poor preservation of these bones does not permit to refer them to either the Discoglossinae (Alytidae) or “ Ranidae ”.