Allocoenia sp.

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1194

Allocoenia sp.

( Fig. 2 )

Allocoenia sp. 1 – Vasseur 2018: 109-110, fig. 3.2.

STUDIED SAMPLES. — Five specimens: 1603A3E5, DA3005E1, DA0106E2-2, MA0504E7-9, MA1004E4-11 (collections CPUN).

GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Koudiat Ech Chehem (Guigou plateau, Middle Atlas of Morocco) and Toarcian of Amellagou and Dadès Valley ( High Atlas of Morocco).

DESCRIPTION

Cerioid massive corallum forming small, rounded, pluricentrimetric colonies. The calices are subcircular to polygonal and multiply by extracalicular increase. Radial elements are straight, free or joined, subcompact septa with welldefined but quite irregular trabecular structure producing irregular granules on lateral faces. The inner edge of septa is sometimes swollen or paliform. The septal apparatus is organized in 3 distinct size orders and sometimes the firstorder septa reach the axial styliform columella. Endotheca made of many vesicular dissepiments. Synapticulae not observed. Wall present, of undetermined nature. No holotheca observed.

Calicular diameter: 1.1 to 4.2 mm – Distance between calice centers: 1.5 to 3.5 mm – Number of septa: 16 to 32 – Septal density: 3 to 5 per 1 mm.

SIMILARITIES AND DIFFERENCES

The comparison with the numerous Triassic and Jurassic species of the genera cited above is still to be done.

Figures

FIG. 2. — Allocoenia sp.: A, distal view of the specimen CPUN DA0106E2-2; B, distal view of the specimen CPUN MA0504E7-9; C, superficial transverse thin section in the specimen CPUN DA0106E2-2; D, Oblique thin section in the specimen CPUN DA0106E3-2; E, transverse thin section in the specimen CPUN MA1004E4-11; F, transverse thin section in the specimen CPUN 1603A3E5. Scale bars: A, B, 1 cm; C, D, 5 mm; E, F, 1 mm.