Rotiphyllum exile de Groot 1963

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 : 19-21

publication ID	https://doi.org/ 10.1186/s13358-023-00296-0
DOI	https://doi.org/10.5281/zenodo.12783857
persistent identifier	https://treatment.plazi.org/id/49386916-7F0B-FFEC-FC91-FD33FDECFB48
treatment provided by	Felipe
scientific name	Rotiphyllum exile de Groot 1963
status

Treatment

( Fig. 10A View Fig 1–A View Fig 4 View Fig , B 1–B View Fig 4 View Fig , C 1–C View Fig 2 View Fig , D 1–D View Fig 2 View Fig , 12C View Fig ).

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 View Fig View Fig .

? 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 View Fig .

1991 Rotiphyllum eoile de Groot. - Kora and Mansour, Fig. 2g View Fig .

1999 Rotiphyllum eoile : Rodríguezand Kullmann, p. 80, Text-figs. 37–40, Pl. 8, Figs. 1–12 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig .

2004 Rotiphyllum eoile de Groot. - Fedorowski, p. 80–82, Pl. 1, Figs. 2–4 View Fig View Fig View Fig ; Pl. 4, Figs. 1–4 View Fig View Fig View Fig View Fig .

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 View Fig 1, B1 View Fig ).

Internal characters: Rotiphyllum with maximum n:d value below the calice 27: 9 mm ( Fig. 10B View Fig 4 View Fig , 12C View Fig ). Counter septum is slightly thicker and longer than counterlateral septa. Cardinal septum is long up to late maturity, thinning with maturity ( Fig. 10C View Fig 2 View Fig ). 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 View Fig 3–B View Fig 4 View Fig ). In addition, the majors of one of the specimens ( Fig. 10A View Fig 3–A View Fig 4 View Fig ) 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 View Fig 1 View Fig ). 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 View Fig 4, B4 View Fig , C 2 View Fig ). Tabulae are common and form at least one incomplete concentric circle around central stereocolumn ( Fig. 10A View Fig 3–A View Fig 4 View Fig , B 3–B View Fig 4 View Fig , C 1–2 View Fig View Fig ). 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 View Fig 3–A View Fig 4, B4 View Fig ). 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 View Fig 1 View Fig and 12A View Fig 2 View Fig ), and is not sufficient for specific differentiation. Concerning n:d ratio, our specimens ( Fig. 12C View Fig ) 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).