Praefusulinella guvenci Akbaş, 2022

Akba, Melikan & Okuyucu, Cengiz, 2022, Fusulinid Biostratigraphy of the Moscovian- Lower Kasimovian of Hadim Nappe, Central Taurides, southern Turkey, Geodiversitas 44 (19), pp. 527-562 : 550

Praefusulinella guvenci Akbaş , n. gen., n. sp.

( Figs 14N, O ; 15A )

urn:lsid:zoobank.org:act:6FD7FF4D-CCA5-4188-AD20-903641460250

HOLOTYPE. — Specimens nos 18G40.14 .

DIAGNOSIS. — A species of Praefusulinella Akbaş , n. gen. with inflated short-fusiform test, slightly straight to convex lateral sides and narrowly rounded poles.

ETYMOLOGY. — This species is named after Prof. Dr. Tuncer Güvenç, in honour of his contributions to the Paleozoic foraminifera and fossil algae biostratigraphy.

MATERIAL EXAMINED. — Three axial sections (specimens nos 18G40.14 , 18G40.16 and 18G40.20 ).

TYPE LOCALITY. — Gölbelen section of Hadim Nappe (BozkIr/ Konya, Central Taurides, Turkey).

STRATIGRAPHIC RANGE. — Carboniferous, Pennsylvanian, upper Moscovian, Podolskian.

OCCURRENCE. — Gölbelen section of the Hadim Nappe (BozkIr/ Konya, Central Taurides, Turkey).

DESCRIPTION

Test large in size and inflated short-fusiform test with slightly straight to convex lateral sides and narrowly rounded poles. All volutions are coiled loosely. The initial first to second volutions are slightly spherical but the nautiloid shell shape is reached in the successive volutions. The last one or two volutions are short-fusiform in shape.Proloculus globular and relatively large, with an outside diameter of 140-180 microns. The number of volutions is up to 5 in advance specimens, and length ranges between 2.58 to 2.65 mm, diameters range between 1.75 to 1.90 mm and form ratios of 1.36 to 1.51. Four-layered wall is thick (0.045 -0.070 mm in the outer volutions), and composed of a tectum, a well-developed and distinct diaphanotheca and dark-thin lower and dark-dense upper tectorium ( Fig. 15B ). Septa regularly folded throughout the coiling axis. Chomata are massive, symmetrical and rounded in shape which present a ridge on the tunnel sides and sloping to the axis. They are subribbon-like in earlier volutions and their heights reach to nearly height of chamber in outermost volutions.

REMARKS

Praefusulinella guvenci Akbaş , n. gen., n. sp. is similar to Praefusulinella okuyucui Akbaş , n. gen., n. sp. and Praefusulinella tekini Akbaş , n. gen., n. sp., but differs from the former by smaller test, loose coiling and nautiloid initial volutions and from the latter by shorter test, nautiloid initial volutions and shape of the chomata.

Figures

FIG. 14. — Thin-section photomicrographs of the fusulinid assemblages of the Yassıpınar (YS), Bademli (BS) and GÖlbelen (GS) sections: A-D, Beedeina schellwieni (Staff in Schellwien & Staff, 1912); A, axial section, 16B40A.09, BS; B, axial section, 16B40C.11, BS; C, axial section, 18G41.15, GS; D, oblique section, 18G45.07, GS; E, F, Beedeina tauridiana Akba ¸s, n. sp.; E, axial section, 16B41.07 (Holotype), BS; F, axial section, 16B41.08, BS; G, detailed view of the wall

FIG. 15. — Thin-section photomicrographs of the fusulinid assemblages of the Yassıpınar (YS),Bademli (BS) and GÖlbelen (GS) sections:A, Praefusulinella guvenci Akba ¸s, n. gen., n. sp., axial section, 18G40.20, GS; B, detailed view of the wall structure of the Praefusulinella guvenci Akba¸s, n. gen., n. sp., 18G40.16 (four-layered wall including tectum, diaphanotheca, lower and upper tectorium); C-G, Praefusulinella okuyucui Akba¸s, n. gen., n. sp.; C, subaxial section, 16B38.13, BS; D, axial section,18G40.03, GS; E, axial section,18G40.07 (Holotype), GS; F, axial section,18G40.18, GS; G, axial section,18G41.10, GS; H, detailed view of the wall structure of the Praefusulinella okuyucui Akba ¸s, n. gen., n. sp., 18G40.03 (four-layered wall including tectum, diaphanotheca, lower and upper tectorium). Scale bar: 1 mm except B, H, 500 µm.