Praeradiolites subtoucasi Toucas, 1907

Săsăran, Liana, Săsăran, Emanoil & Bucur, Ioan I., 2018, Upper Cretaceous Rudist-Bearing Mixed Siliciclastic-Carbonate And - Volcanoclastic Deposits From Strâmturii Valley, Borod Basin, Northern Apuseni Mountains: Description, Microfacies And Depositional Environments, Acta Palaeontologica Romaniae 14 (1), pp. 3-20 : 11-12

Praeradiolites subtoucasi Toucas, 1907

Fig. 7 d-e.

1907 Praeradiolites subtoucasi n.sp. - Toucas, p. 31, pl. 3, figs. 8, 9.

1954 Praeradiolites subtoucasi Toucas- Astre, p. 61, 76- 77, 83, pl. 6, figs. 1, 2.

1962 Praeradiolites cf. subtoucasi Toucas- Astre, p. 306, 308.

1965 Praeradiolites subtoucasi Toucas- Pamouktchiev, p. 37, pl. 4, fig. 1, text-fig. 6.

1976 Praeradiolites subtoucasi Toucas- Lupu, p. 126, pl. 17, figs. 4,5a-b, pl. 39, fig. 6.

1977 Praeradiolites subtoucasi Toucas- Pons, p. 69, pl. 50, figs. 1a-d.

1992 Praeradiolites subtoucasi Toucas- Vicens, p. 201, pl. 75, figs. 1-15, pl. 76, figs. 3-4, pl. 79, figs. 1-5.

1995 Praeradiolites cf. subtoucasi Toucas- Morris & Skelton, p. 292, pl.6, figs.3,4.

1999 Praeradiolites subtoucasi Toucas- Fenerci, p. 90- 94, text-figs. 3.28, 3.29, pl. VII, figs. 1-7.

2004 Praeradiolites subtoucasi Toucas- Fenerci, p. 93, pl. 1, figs. 1-6.

2006 Praeradiolites subtoucasi Toucas- Pons and Vicens, p. 15-16, fig. 13F, fig. 14G.

2012 Praeradiolites subtoucasi Toucas- Pons et al., p. 690, fig. 11B.

2013 Praeradiolites subtoucasi Toucas- Özer et al., p. 35-36, pl. II, figs. A-F; pl. III, figs. A-H.

Material: two lower valves (samples nos.24080, 24081 BBU-MPS).

Description: The shape of RV is conical to cylindrical in both specimens, having 38 and 42 mm in length and its surface is ornamented with horizontal growth lines. Diameter of RV near to the commissure is 30 mm (24081 BBU-MPS) and 35 mm (24080 BBU-MPS) with an oval contour in transverse sections ( Fig. 7d, e ). The outer shell layer is generally thin, ranging from 3 to 8 mm thickness on the dorsal side, were cellular structures alternate with thin calcitic compact layers. In ventral side of both RVs the outer shell layer is very eroded and the radial bands (Vb and Pb) are represented by two longitudinal grooves that show approximately the same width ( Fig. 7d, e ). The Ib is represented by longitudinal costae and has a width ranges from 4 to 7 mm. The ligamental ridge (L) is long (5 respectively 7 mm) has a thin stem and is rounded at its extremity ( Fig. 7d, e ). The cardinal apparatus is preserved showing the teeth (at and pt) and the posterior (pm) and anterior myophores (am) ( Fig. 7e ).

Discussion and remarks: Vicens (1992) designated Praeradiolites aristidis (Munier-Chalmas, 1888) and Praeradiolites echennensis ( Astre, 1954) as synonyms of Praeradiolites subtoucasi ( Toucas, 1907) . Instead, Steuber (1999) described from Greece species of Praeradiolites echennensis ( Astre, 1954) that can be distinguished from the other two species ( P. aristidis and P. subtoucasi ) therefore considered P. echennensis as valid species.

Age and distribution: late Santonian-early Campanian in France ( Astre, 1962), Spain ( Vicens, 1992), Romania ( Lupu, 1976; Săsăran et al., 2010); Maastrichtian in Croatia ( Gušić and Jelaska, 1990; Steuber et al., 2005), Oman ( Morris and Skelton, 1995), Turkey ( Fenerci, 1999, 2004), Iraq ( Özer et al., 2013).

Figures

Fig. 7 a, b Bournonia excavata d'Orbigny, 1847, (inventory no. 24078 BBU-MPS =no.1246 sample field); a transverse section through RV close to the commissure, showing the myocardinal elements: anterior and posterior tooth and myophores (am, pm) of the opposite valve; b view of flat posteroventral side of RV; c Gorjanovicia endrissi (Böhm)(24079 BBU-MPS) – transverse section of RV showing compact layer, concave ventral band (Vb); Ib- narrow and wide Pb with 3 fine rounded costae; d, e Praeradiolites subtoucasi (Toucas): d transverse section through RV (24080-BBU-MPS), unknown commissure. The outer shell layer from ventral side is eroded thus the radial bands are missing. e transverse section on other specimen (24081-BBU- MPS) having outer shell layer partially broken but preserve the myocardinal apparatus. f, g Radiolites squamosus (d'Orbigny): f specimen with both valves showing convex LV, very eroded and the ornamentations of RV consist in dense growth lamellae (sample no. 24082 BBU-MPS); g ventral side of RV of the same specimen showing radial bands (Vb and Pb) with folds upward to commissure and the narrow interband (Ib). h-i Radiolites nouleti (Bayle)(sample no. 24083 BBU-MPS): h large conical RV, thick-shelled, with dense folded growth lamellae, slightly ondulated in large interband (Ib); i transverse section in RVof the same specimen, showing thick cellular outer shell layer, ligamental ridge and accessory cavities. j, k Sphaerulites boreaui (Toucas)(sample no. 24084 BBU-MPS), j specimen with both valves, top view, showing LV, thin and smaller than lower valve and large RV with expanded, sub-horizontal growth lamellae; k transverse section through RV, showing thickness of cellular