Margarosmilia, Volz, 1896

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1244

Margarosmilia ? sp.

( Fig. 38 )

Margarosmilia ? sp. 1 – Vasseur 2018: 236-237, fig. 3.54.

STUDIED SAMPLES. — Two specimens: CPUN DA2905E1-2, CPUN DA2905E2-1. GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Dades Valley ( High Atlas of Morocco).

DESCRIPTION

Phaceloid colony with huge subcircular calices often distorted by intracalicular budding. Radial elements are free, straight or curved, compact costosepta except in the most inner part of septa where septal trabeculae dissociate sometimes in the close elongated fossa but never produce a real columella. Lateral faces of septa hold pennula-like granules that alternate from one side to the other of one single septum, in accordance with the description of the genus Margarosmilia in Cuif (1975). A wavy mid-septal line seems to appear even if the poor preservation of the specimens does not allow a clear confirmation. Endotheca made of quite abundant thin vesicular dissepiments. Synapticulae not observed. An epicostal epitheca s.l. wraps the corallites.

Calicular diameter: 12 to 23 mm – Distance between calices centers: 25 to 40 mm – Septal density: 4 to 6 per 2 mm.

REMARKS

We place with doubt these specimens under the genus Margarosmilia because the poor preservation of the specimens does not allow to confirm the presence of a mid-septal line (even if some ghosts of these structures seem to exist) and because of the subcompact nature of the very inner edge of septa; however, this last character appears for us compatible with the structure described in Cuif (1975).

Figures

FIG. 38. — Margarosmilia? gemminata Beauvais, 1986: A, distal view of the polished specimen CPUN DA2905E2-1; B, transverse polished section of two separating calices on the specimen CPUN DA2905E2-1; C, transverse thin section of the specimen CPUN DA2905E1-2. Note the Hispaniastraea colony attached at the right lower side; D, detail in transverse oblique thin section of the septal structure of the specimen CPUN DA2905E2-1; E, detail in transverse thin section of the axial part of one corallite of the specimen CPUN DA2905E2-1 (skeleton in bright at the center); F, detail in transverse thin section of the septal structure of the specimen CPUN DA2905E2-1. Scale bars: A, 5 cm; B, 1 cm; C, D, 4 mm; E, F, 2 mm.