Rotiphyllum exile de Groot 1963
Creators: name: El-Desouky, Heba
name: Herbig, Hans-Georg
name: Kora, Mahmoud
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Stauriida
Metriophyllidae
Rotiphyllum
Rotiphyllum exile

description: Rotiphyllum exile de Groot 1963
(Fig. 10A 1–A 4, B 1–B 4, C 1–C 2, D 1–D 2, 12C).
1963 Rotiphyllum eoile de Groot, p. 8, Text-fig. 1, Pl. 1, figs. 1–2.
1963 Rotiphyllum equabilae de Groot, p. 9, Text-figs. 2–3, Pl. 1, Figs. 3–4.
? 1984b Rotiphyllum eoile: Rodríguez, p. 122, Text-figs. 33–34, Pl. 1, figs. 1–2.
1991 Rotiphyllum equabilae de Groot. —Kora and Mansour, Fig. 2d.
1991 Rotiphyllum eoile de Groot. - Kora and Mansour, Fig. 2g.
1999 Rotiphyllum eoile: Rodríguezand Kullmann, p. 80, Text-figs. 37–40, Pl. 8, Figs. 1–12.
2004 Rotiphyllum eoile de Groot. - Fedorowski, p. 80–82, Pl. 1, Figs. 2–4; Pl. 4, Figs. 1–4.
Material: Ten corallites; RAh 21, RAh 26, RAh 29, RAh 46, RAh 56, RAh 69, RAh 116 and RAh 117, collected from the basal shales of the lower member of the Aheimer Formation. Twenty-one transverse thin-sections are available.
Description: External characters: Small, straight conical to slightly curved corallites. The preserved parts of the corallites range in length between about 1.5 cm and 2.5 cm. Fairly good preserved specimens, with either eroded or compressed and crushed calices. Calices are very deep (up to 10 mm). Apexes are eroded. Septal furrows are developed on the external wall of the corallites (Fig. 10A 1, B1).
Internal characters: Rotiphyllum with maximum n:d value below the calice 27: 9 mm (Fig. 10B 4, 12C). Counter septum is slightly thicker and longer than counterlateral septa. Cardinal septum is long up to late maturity, thinning with maturity (Fig. 10C 2). Inner margins of major septa join at the axis to form a stereocolumn. In few cases a small axial tube is developed in mature stages (Fig. 10B 3–B 4). In addition, the majors of one of the specimens (Fig. 10A 3–A 4) do not form a dense stereocolumn in mature stages like in the other individuals of this species. This is due to the irregular manner of the last major septa in quadrants and the formation of the alar fossulae. Major septa are radially arranged in adult stage and pinnately arranged in early ontogenetic stages (Fig. 10D 1). In some specimens, major septa preserve a white middle line. Minor septa are rudimentary developed mostly in late mature stages, below the calice (Fig. 10A 4, B4, C 2). Tabulae are common and form at least one incomplete concentric circle around central stereocolumn (Fig. 10A 3–A 4, B 3–B 4, C 1–2). The cardinal fossula is rectangular to slightly triangular in shape and narrows adaxially. The alar fossulae are occasionally well-marked by the thin and irregular last major septa in the counter quadrants (Fig. 10A 3–A 4, B4). The thin to moderately thick wall is formed or at least enforced by the peripheral thickened septa.
Discussion: In their morphology the Egyptian specimens are almost identical to the species described from the type region in the Cantabrian Mountains, northern Spain (de Groot, 1963; Rodríguez and Kullmann, 1999). Tabulae appear to be less and slightly more irregularly developed, although similar transverse sections were figured by Rodríguez and Kullmann (1999, text-Fig. 37 c1–c2, d). This might be related to the less mature position of our transverse sections (compare Figs. 10A 1 and 12A 2), and is not sufficient for specific differentiation. Concerning n:d ratio, our specimens (Fig. 12C) plot into the upper range of the individuals of Rodríguez and Kullmann (1999, text. Fig. 40). The white middle line seen in the major septa of some specimens might correspond to the relict of the trabecular microstructure described by Fedorowski (2004).
Geographic and stratigraphic range: Rotiphyllum eoile de Groot, 1963 was described from the Westphalian D (Asturian, upper Moscovian) of the Cantabrian Mountains (see Rodríguez et al., 2022 and references in the synonymies listed herein). According to Fedorowski (2004), its occurrence in the Westphalian C of the Escalada Formation (Rodríguez, 1984b; Podolskian according to Rodríguez, 1985) is questionable. The species was previously reported from the western side of the Gulf of Suez by Kora and Mansour (1991).
description: Published as part of 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, pp. 1-39 in Swiss Journal of Palaeontology (32) (32) 142 (1) on pages 19-21, DOI: 10.1186/s13358-023-00296-0, http://zenodo.org/record/12003174