Stylosmilia ” dresnayi Beauvais, 1986, 1848

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1252-1253

“ Stylosmilia ” dresnayi Beauvais, 1986

( Fig. 45 )

Stylosmilia dresnayi Beauvais, 1986: 41 , pl. 8, fig. 3.

Stylosmilia? dresnayi – Vasseur 2018: 338-339, fig. 3.93.

TYPE MATERIAL. — Holotype: MNHN.F.R11623, Beauvais 1986: 41, pl. 8, fig. 3. TYPE HORIZON. — Pliensbachian . TYPE LOCALITY. — Jebel Bou Dahar , Morocco. STUDIED SAMPLES. — Two specimens: holotype MNHN.F.R11623; CPUN Gu 1005E2. GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Jebel Bou Dahar and Guigou Plateau , Morocco.

DESCRIPTION

Phaceloid colony with cylindrical corallites multiplying by extracalicular budding. Radial elements are wavy, compact costosepta apparently free and organized in two distinct size-orders. External lateral faces of the corallites are ornamented with vertical striation made by the naked costae. Styliform columella according to Beauvais (1986) but that does not appear clearly in the sample. Endotheca made of rare dissepiments and tabulae that periodically divide the lumen vertically. Wall present, probably septothecal. No synapticulae observed.

Calicular diameter: 1.5 to 2.5 mm – Number of septa: 32 to 36 – Septal density: 3 to 4 for 0.5 mm.

SIMILARITIES AND DIFFERENCES

Differs from the other taxa of the genus Stylosmilia Milne Edwards, 1848 by the lack of auriculae. With the doubt concerning the presence of a styliform columella we choose to maintain the species under the genus Stylosmilia (with quotation marks) even if the genus Proaplophyllia Roniewicz, 1976 would be more appropriate in case of lack of columella.

Figures

FIG. 45. — “Stylosmilia” dresnayi Beauvais, 1986: A, distal view of the holotype MNHN.F.R11623; B, polished longitudinal section in one corallum of the holotype MNHN.F.R11623; C, transverse thin section in one corallum of the holotype MNHN.F.R11623; D, transverse thin section in the holotype MNHN.F.R11623; E, oblique thin section of septa in a corallum of the holotype MNHN.F.R11623. Scale bars: A, 1 mm; B, D, 2 mm; C, E, 0.5 mm.