Praefusulinella rhombiforma 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 : 554

Praefusulinella rhombiforma Akbaş , n. gen., n. sp.

( Fig. 16 A-C)

urn:lsid:zoobank.org:act:21A32D06-9595-4D05-849A-5AE675339331

HOLOTYPE. — Specimen no. 18G40.11 .

DIAGNOSIS. — A species of Praefusulinella Akbaş , n. gen. with very large and rhomboidal test, straight lateral sides and pointed poles.

ETYMOLOGY. — This new species is named for its rhomboidal test.

MATERIAL EXAMINED. — Three axial sections (specimens nos 18G40.06 , 18G40.10 and 18G40.11 ).

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 very large in size and rhomboidal in shape with straight lateral sides and pointed poles. The test is tightly coiled. All initial volutions are ovoid in shape, but the outermost whorl is rhomboidal in shape. Proloculus globular and relatively large, with an outside diameter of 150-210 microns. The number of volutions is up to 5-6 in advance specimens, and length ranges between 2.93 to 4.13 mm, diameters range between 1.75 to 2.38 mm and form ratios of 1.60 to 1.74. Four-layered wall is moderately thick (0.045 -0.050 mm in the outer volutions), and composed of a tectum, a prominent diaphanotheca and dark-dense lower and upper tectorium ( Fig. 16D ). Septa folded across the coiling axis. Chomata are massive, symmetrical and subribbon-like in shape and their heights reach to half height of chamber.

REMARKS

Praefusulinella rhombiforma Akbaş , n. gen., n. sp. shows similarity with Fusulinella bocki bocki and Fusulinella bocki timanica , but it easily differs from them by ovoid initial volutions and subribbon-like chomata.

Figures

FIG. 16. — Thin-section photomicrographs of the fusulinid assemblages of the Yassıpınar (YS), Bademli (BS) and GÖlbelen (GS) sections: A-C, Praefusulinella rhombiforma Akba ¸s, n. gen., n. sp.; A, axial section, 18G40.06, GS; B, axial section, 18G40.10, GS; C, axial section, 18G40.11 (Holotype), GS; D, detailed view of the wall structure of the Praefusulinella rhombiforma Akba¸s, n. gen., n. sp., 18G40.11 (holotype) (four-layered wall including tectum, diaphanotheca, lower and upper tectorium); E-I, Praefusulinella tekini Akba¸s, n. gen., n. sp.; E, axial section, 18G40.12, GS; F, axial section, 18G40.13, GS; G, axial section, 18G40.15, GS; H, axial section, 18G40.17.01, GS; I, axial section, 18G40.21 (holotype), GS; J, detailed view of the wall structure of the Praefusulinella tekini Akba¸s, n. gen., n. sp., 18G40.21 (holotype) (four-layered wall including tectum, diaphanotheca, lower and upper tectorium). Scale bar: 1 mm except D, J, 500 µm.