Zaphrentites parallela
Creators: name: El-Desouky, Heba
name: Herbig, Hans-Georg
name: Kora, Mahmoud
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Stauriida
Hapsiphyllidae
Zaphrentites
Zaphrentites parallela

description: Zaphrentites cf. parallela (Carruthers, 1910).
(Fig. 11A 1–A 3, B 1–B 4, 12D).
cf. 1910 Zaphrentis parallela Carruthers. - p. 533, Pl. 37, Fig. 4.
cf. 2014 Zaphrentites parallela (Carruthers).- Denayer and Hoşgör, p. 350, Fig. 4: 6a–d, 14 (cum syn.).
Material: Three corallites (RAh 109, RAh 111 and RAh 118); collected from the basal shales of the lower member of the Aheimer Formation. Nine transverse thin-sections are available.
Description: External characters: Straight, conical corallites, about 1.5 cm long, slightly curved in the immature stage. Calyx is largely eroded, apex not preserved. Septal furrows and delicate growth lines are distinctly marked on the external wall (Fig. 11B 1). An attachment scar is visible in one corallite near the apical part.
Internal characters: In the earliest ontogenetic preserved stage (Fig. 11A 1), septa are very thick, reaching the corallite axis. There are 16 septa at a corallite diameter of about 3 mm; of them the counter septum is the thickest. At diameter of 3.7 mm (Fig. 11B 2), major septa are still thick, they join in the centre forming a thick stereocolumn; a parallel sided cardinal fossula can be recognised. In the subsequent early mature growth stage at a diameter of 5 mm, there are 20 major septa (Fig. 11A 2). Minor septa are absent. The axial ends of major septa join to form an axial stereocolumn slightly staggered towards the counter quadrants. Septa of the counter quadrants are radially arranged, the counter septum is slightly thicker and has the same length as the adjacent septa. Those in the cardinal quadrants are grouped pinnately around a long parallel sided cardinal fossula. The thin cardinal septum is straight, long and reaches beyond the corallite axis to join the stereocolumn at the upper end of the cardinal fossula in the counter quadrants. It further thins towards the axis. Further mature, at a diameter of 6.5 mm, there are 21 septa (Fig. 11B 3); the cardinal septum becomes slightly shorter.
The uppermost mature transverse section near the calice floor (Fig. 11A 3, B 4) is slightly deformed due to compaction and some of the septa are broken. In this stage there are maximum 26 septa in 8.6 mm (Fig. 11B 4). Axial ends of the major septa in cardinal quadrants are bent to sides with the two pericardinal septa, curved most distinctly. Such septal morphology makes the cardinal fossula opens towards the free axial area. The cardinal fossula is slightly deformed. The cardinal septum is short, and the counter is slightly longer and thicker than the adjacent septa. All major septa are thick at the base, join at their rhopaloid ends around the well-developed cardinal fossula, which invades the counterpart, being longer than the radius of the corallite. Pseudoalar fossulae are not markedly developed. Minor septa are absent from the corallite lumen, they are visible in the stereoplasm of the wall.
Discussion: According to the septal arrangement and the axial stereocolumn, the current species clearly belongs to the genus Zaphrentites. It is closely similar to Z. parallela (Carruthers, 1910) in the septal arrangement and more or less in the shape of the cardinal fossula, with the cardinal septum withdrawn in late stages. However, our specimens reach larger n:d ratios (Fig. 12D) in the last mature stage near the calice (26:8.6 vs. 20:5.6). Z. delanouei (Milne-Edwards and Haime, 1851) and Z. crassus Hudson, 1944 are both larger and have more septa than the herein described species. It is quite similar to Z. parallela of Denayer and Hoşgör (2014) from the Lower Carboniferous of Turkey. It differs in the n:d ratio of the last mature stage (21:8.5) and in general counts more septa at the same diameter.
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 21-24, DOI: 10.1186/s13358-023-00296-0, http://zenodo.org/record/12003174