Ufimia sp.

El-Desouky, Heba, Herbig, Hans-Georg & Kora, Mahmoud, 2023, Kasimovian (late Pennsylvanian) cornute rugose corals from Egypt: taxonomy, facies and palaeogeography of a cool-water fauna from northern Gondwana, Swiss Journal of Palaeontology (32) 142 (1), pp. 1-39 : 26

Ufimia sp.

( Fig. 13A 1–A 3 ).

Material: Two corallites (RAh 101 and RAh 114), with four transverse thin-sections; collected from the basal shales of lower member of the Aheimer Formation.

Description: External characters: Straight, conical corallites, the preserved part of both range in length from 1.5 to 2 cm. The calices are eroded, and the apical parts are not preserved. The external wall does not show any septal furrows ( Fig. 13A 1 ).

Internal characters: There are 20 major septa in a diameter of 5.5 mm ( Fig. 13A 2 ), they are all very thick, the longest of them reach the corallite axis with rhopaloid ends. The corallite lumen is filled with stereoplasm. Below the calice there are still 20 major septa in a diameter of 7 mm ( Fig. 13A 3 ). Major septa are thick, rhopaloid, withdrawn a little from the centre which is largely filled with stereoplasm. At this stage of maturity, the cardinal septum becomes shorter and thinner towards the centre within indistinct fossula in contrast to the other major septa. The counter septum also becomes shorter than the counter-laterals. The alar septa exceed the major septa in length and in thickness. Septa are strongly accelerated in number in counter quadrants. Tabulae are not observed in transverse sections. Minor septa are underdeveloped.

Discussion: Ufimia alternans from the upper Moscovian of Spain differs from the current species in the following:

• Ufimia alternans de Groot, 1963 is larger than the current species; The Spanish species reaches max. 24: 13 mm vs. 20: 7 mm in the Egyptian species.

• The biform tabularium of the Spanish species is not expressed in the current species.

• The Spanish species is characterised by the alternation of long and short major septa, a feature that is not found in the Egyptian Ufimia .

Figures

Fig. 13 A Ufimia sp. A1 External view of the specimen RAh (101), showing a straight conical corallite with eroded calice rim and apex. Positions of thin-sections indicated. A2–A3 Two successive transverse thin-sections in the mature part of the corallite show the thick, rhopaloid major septa meet in the corallite centre. Scale bars:A1: 5 mm; A2, A3: 2 mm. B Bothrophyllum okense Kossovaya, 2001. B1 External view of the partly preserved corallite (RAh 37), with partly eroded wall. Positions of thin-sections indicated. Successive transverse thin-sections from the lower less mature part in B2 up to the more mature section below the calice in B4, the transverse sections show the axial septum and a very narrow dissepimentarium. Scale bars: 5mm

Fig. 1 Geological map of the eastern cliffs of the Northern Galala Plateau, modified after Abdallah and El Adindani (1965)

Fig. 3 Field aspects of the Aheimer Formation; A General view of the studied succession of the lower member exposed in a faulted block to the north of Porto Sukhna; the shales mudstones close to the base (rectangle) are interbedded with thin, hard dolomitic bands. B Close up view on of the lower fossiliferous shale mudstone beds of A. C, D Close-up view on of two rugose corals entombed in the shale mudstone beds.E Close-up view on of a rugose coral species with diagenetically compressed calyx. Note strong ferrugination of corallite and surrounding matrix within the fossiliferous shale. F Fossiliferous shales mudstone with thin bands of ferruginous dolomitic limestone and secondary evaporite veinlets; Cr = crinoidal stems. G Crinoid columnals (Cr) and rugose corals (RC) are embedded in the shale mudstone. H Close-up view on of a spiriferid valve shell within the shale (arrow). Diameter of coins in C–E, G: 25 mm

Fig. 2 A Lithostratigraphic succession of the Aheimer Formation studied along the eastern cliffs of the Northern Galala Plateau after Kora and Mansour (1992). B Enlargement of the mudstone dominated basal shale part of the lower member of the Aheimer Formation studied herein (see also Fig. 3A)