Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 80. (Budapest 1988)

Pálfy, J.: Middle Triassic rhynchonellids from the Balaton Highland (Transdanubian Central Range, Hungary)

Fig. 11. Distribution of the number of costae on the brachial valve of Caucasorhynchia altaplecta (BÖCKH, 1872). (The holotype has three costae.) 2 3 A 5 6 Genus Piarurhynchella DAGYS, 1974 Piarorhynchella irinodosj (BITTNER, 1890) (Plate 3: figs 5-6; Figs 13-14) 1890 Rhynchonella trinodosi sp. n. — BITTNER: p. 13, pi. 32: figs 17-33. 1899 Rhynchonella trinodosi BITTN. — BITTNER: p. 14, pi. 2: fig. 10. 71933 Rhynchonella trinodosi BITTN. — MILOSAVLJEVIC: p. 211, pi. 1 : fig. 5. 1963 "Rhynchonella" trinodosi BITTNER — ASSERETO: p. 24, pl. 1 : fig. 1. 1967 Piarorhynchia''. trinodosi (BITTNER) — CASATI et GNACCOLINI: p. 123, pi. 9: figs 5-6. 1967 Piarorhynchia'1 trinodosi (BITTNER) — SPECIALE: p. 1085, pi. 79: figs 2-3. 1969 Piarorhynchia trinodosi (BITTNER) — GAETANI: p. 499, pi. 33: figs. 8-9, pi. 34: figs. 1-7. textfigs. 6-7. 1971 Piarorhynchia trinodosi (BITTNER) — SIBLIK: p. 173, pi. 20: figs 2-3. 1986 Piarorhynchella trinodosi (BITTNER) — KOCHANOVA et MICHALIK: p. 517, figs 5, 7-8. Material: 28 specimens from the Forrás Hill near Felsőörs, most of them are silicified shells. 4 specimens from Köveskál, 2 of them are complete. 8 specimens from Aszófő, originating from the upper part of the sequence. Dimensions: The following table presents the data of five characteristic specimens. (The abbreviations stand for the locality. 1 = Köveskál, 2 = Felsőörs. 1 1 2 2 Length 9.6 8.8 6.5 7.3 10.1 Width 9.7 8.1 5.8 7.1 10.8 Thickness 6.9 5.2 3.9 4.2 6.5 Description — External characters: Small to medium-sized shell, rounded subtrigonal in outline. Both valves are convex, though the pedicle one is slightly flatter. Maximum of width is located at the anterior margin, maximum thickness is at the anterior third. The divergence of the lateral margins forms an angle of 75-80°. The anterior commissure is uniplicate. The fold is wide, its height may vary. The posterior part of the valves is smooth, both the costation and the plication become apparent at half, or at the anterior third cf the length. There are 2 or 3 costae in the dorsal fold, 1 or 2 costae in the ventral sinus and 2 or 3 costae on the lateral flanks. The profile of the costae and the intervals are trigonal, rounded at the beginning, but toward the anterior margin it becomes sharper and higher. Fig. 12. Drawing from the anterior view of a specimen of Holcorhynchella delicatuia (BITTNER, 1890) from Aszófő. Width 6.2 mm.