Pseudomphalocyclus blumenthali, a New Genus and Species from the Upper Maastrichtian of Southern Turkey

Abstract

Pseudomphalocyclus blumenthali, a new orbitoid taxon, is described from the upper Maastrichtian of Bolkar Mountain in the Taurus range of southern Turkey. Pseudomphalocyclus blumenthali, a new genus and species from the upper Maastrichtian of southern Turkey INTRODUCTION In southern Turkey, scattered outcrops of the upper Maastrichtian are found along the northern flanks of Bolkar Mountain, in the area between Uluki?la (Nigde) and Pozanti (Adana) (text-fig. 1). The exposure at Kalkankaya has yielded the richest fauna. In this locality, the sequence starts with basal conglomerates, and continues with well-bedded, gray, locally cherty and dolomitized limestones. It has an approximate thickness of 200-300 m. This unit overlies the ophiolite-melange and Ciftehan Formation disconformably, and is itself conformably overlain by the Paleocene-Eocene Halkapinar Formation (see text-fig. 2; Demirta?li et al., 1973). According to Demirta?li et al. (1973) the limestones contain Loftusia minor Cox, Siderolites calcitrapoides Lamarck and Omphalocyclus macroporus (Lamarck). Blumenthal (1956), who first studied the region in detail, stated that limestone horizons at Kalkankaya contain a very rich microfauna consisting of Loftusia minor Cox, L. harrisoni Cox, Orbitoides medius (d'Archiac), 0. apiculatus Schlumberger, Omphalocyclus macroporus, Torreina torrei Palmer, Cuneolina sp., Quinqueloculina sp. During my study in this region, Loftusia minor, Orbitoides medius, 0. apiculatus, Omphalocyclus macroporus, Pseudomphalocyclus blumenthali Meri;, n. gen., n. sp., Cuneolina sp., valvulinids and rotaliids were found in the samples collected from Kalkankaya (see text-fig. 1 and table 1), and Loftusia minor, Orbitoides sp., Pseudomphalocyclus blumenthali, Cuneolina sp., valvulinids, miliolids and rotaliids were found in the samples collected from the Horoz locality (see text-fig. 1 and table 1). Both fossil assemblages indicate an upper Maastrichtian age. Although numerous thin-sections have been examined, Loftusia harrisoni and Torreina torrei, mentioned by Blumenthal (1956), have not been observed. In this study, 24 samples were used (13 from Kalkankaya and 11 from Horoz) and 66 thin-sections were prepared and examined. Because of the well-indurated nature of the rocks, free specimens could not be obtained. All the measurements of the test, embryonic apparatus and chambers were made externally. micropaleontology, vol. 26, no. 1, pp. 84-89, pls. 1-2, 1980 84 This content downloaded from 207.46.13.193 on Thu, 08 Sep 2016 04:55:13 UTC All use subject to http://about.jstor.org/terms Micropaleontology, vol 26, no. 1, 1980 TEXT-FIGURE 1 Index map showing general location of samples collected. SYSTEMATIC DESCRIPTION Phylum PROTOZOA Goldfuss, 1817 Class RHIZOPODEA von Siebold, 1845 Order FORAMINIFERIDA Eichwald, 1830 Superfamily ORBITOIDACEA Schwager, 1 876 Family ORBITOIDIDAE Schwager, 1876 Subfamily OMPHALOCYCLINAE Sigal, 1952 Pseudomphalocyclus Meric, n. gen. Derivation of name: In general, this fossil shows the characteristics of the subfamily Omphalocyclinae. Therefore, the name Pseudompholacyclus is given. This new form shows great similarity to the genus Omphalocyclus Bronn in its test shape and the general characteristics seen in axial and equatorial sections of the type species. Therefore, it should be included in the Omphalocyclinae subfamily. However, it is clearly differentiated from Omphalocyclus by the presence of lateral chambers and pillars in axial sections. As is well known, there is no such development in Omphalocyclus (see Vredenburg, 1908; Douville, 1921; Rutten, 1941; Kupper, 1954; Renz, 1955; Neumann, 1958; Meri9, 1965,1 967a, 1967b).