Late middle Miocene amphibians and squamate reptiles from Taut ,, Romania
Venczel, Márton
Stiuc, Emanoil
Geodiversitas
2008
30
4
731
763
(Lartet, 1851)
Lartet
1851
[246,589,1299,1326]
Amphibia
Alytidae
Latonia
GBIF
Animalia
Anura
10
741
Chordata
species
gigantea
MATERIAL EXAMINED. —Two premaxillae ( ISERTt-0370/1 and 2), eight maxillae ( ISERTt-0371/1-8), five frontoparietals ( ISERTt-0372/1-5), one presacral vertebra ( ISERTt-0373), one coracoid ( ISERTt-0374), one humerus ( ISERTt-0375), two ilia ( ISERTt-0376/1 and 2).
DESCRIPTION Premaxilla The anterior surface of the premaxilla is smooth ( Fig. 6B, B’). The alary process is relatively wide and convex dorsally. The palatine process is well developed; there are 18 tooth positions preserved on the premaxilla. Late middle Miocene amphibians and reptiles from Taut,, Romania Frontoparietal The best preserved specimen, representing a posterior half of a frontoparietal, belonged to a relatively large sized individual ( Fig. 6A, A’). The dorsal surface is broad and covered by a dense secondary sculpture; the tubercules tend to form rows near the posterior and lateral margins. The ventral surface exhibits the posterior part of frontoparietal incrassation, which is roughly circular. The latter structure is bordered laterally by prominent bony laminae diverging posteriorly, which represents the pars contacta( Roček 1994). Maxilla Most specimens are fragmentary and represent different maxillary parts ( Fig. 6C-F’). The processus zygomaticomaxillariswas presumably rather high as suggested by ISER Tt-0371/1( Fig.6C,C’).The labial surface is covered by secondary sculpture formed by prominent tubercles which stay dispersed or usually constitute confluent rows. The extent of labial sculpture displays a wide ontogenetic variation. In smaller (i.e. younger) individuals the sculpture covers only the posterior maxillary region as seen in ISER Tt-0371/2 ( Fig. 6F, F’), but in larger (i.e. older) specimens it usually reaches the level of the palatine process. The pterygoid process is prominent and projects posteromedially.The posterior depression is usually shallow and limited anteriorly by a transversal bony ridge at the level of the pterygoid process. The horizontal lamina is rather wide and convex lingually. The tooth row extends posteriorly to the level of the pterygoid process, but in some specimens (e.g. ISER Tt-0371/3) is just finished at that level ( Fig. 6E). Presacral vertebra The only available specimen(ISER Tt-0373) is opisthocoelous and provided with well-developed interzygapophyseal ridges and a low neural ridge ( Fig. 7A, A’). However, a distortion is observed: the neural ridge is shifted rightwards,while the right postzygapophysis is positioned more anteriorly with its long axis oriented more laterally than that of the left side. Coracoid In the only available fragmentary specimen, the shaft is slightly curved and provided with a low ridge on Venczel M. & Ştiucă E. A FIG. 6. — Latonia gigantea(Lartet, 1851): A, A’, frontoparietal (ISER Tt-0372/1); B, B’, premaxilla (ISER Tt-0370/1); C, C’, maxilla (ISER Tt-0371/1); D, D’, same (ISER Tt-0371/2); E, E’, same (ISER Tt-0371/3); F, F’, same (ISER Tt-0371/4); A, B’, ventral views; A’, B, dorsal views; C, E’, right lateral views; C’, D, E, F, medial views; D’, F’, left lateral views. Scale bar: 2 mm. Late middle Miocene amphibians and reptiles from Taut,, Romania A B FIG. 7. — Latonia gigantea(Lartet, 1851): A, A’, presacral vertebra (ISER Tt-0373); B, B’, humerus (ISER Tt-0375); C, coracoid (ISER Tt-0374); D, ilium (ISER Tt-0376/1); A, B, dorsal views; A’, B’, C, ventral views; D, right lateral view. Scale bar: 2 mm. Venczel M. & Ştiucă E. FIG. 8. — Palaeobatrachuscf. hiri: A, premaxilla (ISER Tt-0381), posterior view; B, nasal (ISER Tt-0380),ventral view; C, pterygoid (ISER Tt-0384), dorsal view; D, urostyle (ISER Tt-0385), dorsal view; E, tibiofibula (ISER Tt-0386), posteromedial view. Scale bar: 2 mm. its posterior surface ( Fig. 7C). The pars glenoidalisis strongly dilated with a rounded shape. Humerus ISER Tt-0375 represents the fragmentary distal shaft of a humerus which belonged to an extremely large individual ( Fig. 7B, B’). The distal humeral ball is rounded and is slightly shifted laterally; the medial epicondyle is rather prominent. Ilium ISER Tt-0376 lacks the supraacetabular region and most part of preacetabular region ( Fig. 7D). A small preacetabular fossa is present. The tuber superior is well defined without a lateral projection. The iliac crest was rather high.
REMARKS The material of L. gigantearecovered from Tauţ, mostly consisting of skull bones, belonged almost exclusively to specimens of relatively large size. These remains are easily distinguishable from L. rageiHossini, 1993, another large discoglossid within the stratigraphic range of L. gigantea( Böhme & Ilg 2003), because despite its similarly large size lacks a secondary sculpture. In L. seyfriediMeyer, 1843, known from the late middle Miocene (MN 8) of Oehningen ( Germany) only( Roček 1994), the holotypeand all the referred specimens are imbedded in the sediment by their dorsal side. Consequently it is not known if its skull bones bear or not a secondary sculpture. However, if the latter character would be present in L. seyfriedi, then L. giganteawill become a junior synonym of the former. Thus, only further investigation of the type material would answer this taxonomic problem. Family PALAEOBATRACHIDAE Cope, 1865