Retiophyllia zizensis, Vasseur & Lathuilière, 2021

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1252

Retiophyllia zizensis n. sp.

( Fig. 44 )

urn:lsid:zoobank.org:act:3D62AE51-03F4-401D-9F68-BA85BF71F78B

Retiophyllia sp. 1 – Vasseur 2018: 320-321, fig. 3.86.

Retiophyllia sp. – Brame et al. 2019: fig. 7C-D.

TYPE MATERIAL. — Holotype: CPUN DA2705E1; paratypes: CPUN DA2705E2, CPUN DA2705E7, CPUN DA2805E7. TYPE HORIZON. — Upper Pliensbachian . TYPE LOCALITY. — Bin El Ouidane, 32°4’1”N, 4°22’57”W, Ziz valley of Morocco. STUDIED SAMPLES. — Four specimens: CPUN DA2705E1, CPUN DA2705E2, CPUN DA2705E7, CPUNDA2805 E7. GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Ziz valley – Bin El Ouidane ( High Atlas of Morocco).

DESCRIPTION

Phaceloid coral with subcylindrical corallites growing by extracalicular parietal increase similar to those described for Placophyllia by Beauvais (1976). Costosepta compact, free or linked by their inner edge (first size-order of septa), straight or wavy, structured in three or four distinct sizeorders. S1 and most of the S2 are characterized by a bicuneiform transverse section and lateral faces showing rare small and irregular granules. Their inner edge is sometimes clearly rhopaloid. Mid-septal line in zigzag can be guessed. The fifth order septa are generally straight and thin with smooth lateral faces although some S3 show a thickening in their external part suggesting a transition between septal shape of lower and upper orders. Parathecal wall absent or sparse and incomplete. A true epitheca encloses the corallite. Endotheca is well developed, made of thin vesicular dissepiments in periphery backing onto the inner side of the epitheca, and thin and regular tabular dissepiments dipping into the center of the corallite. No columella, nor synapticulae.

Calicular diameter: 4 to 10 mm – Distance between calices centers: 6 to 10 mm – Number of septa: 32 to 48 – Septal density: 5 for 2 mm.

SIMILARITIES AND DIFFERENCES

Differs from the Triassic species by its smaller number of septa, an extracalicular parietal growth mode, an irregular and sparse septal ornamentation, a distance between calices generally greater and the lack of continuous septothecal wall. This taxon also differs from R. ahraboutensis Beauvais, 1986 by the lack of continuous septothecal wall and also by longer S1 septa that fill more extensively the axial space.

Figures

FIG. 44. — Retiophyllia zizensis n. sp: A, Specimen pictured in the field (Bin El Ouidane,Morocco,N32°067180 - W4°382511);B, transverse section in the specimen CPUN DA2705E1; C, detail of extracalicular budding in the specimen CPUN DA2705E1; D, longitudinal section the specimen CPUN DA2705E1; E, transverse thin section in the specimen CPUN DA2705E7-1; F, detail in transverse section showing zig-zag mid-septal line in the specimen CPUN DA2805E7.Scale bars: A, 2 cm; B, C, D, 5 mm; E, 6 mm; F, 1 mm.