Pliensbachian corals from the Western Tethys Author Vasseur, Raphaël Université de Lorraine, CNRS, lab. GeoRessources, UMR 7359, BP 70239, F- 54506 Vandoeuvre-lès-Nancy cedex (France) raphaelvasseur@wanadoo.fr Author Lathuilière, Bernard Université de Lorraine, CNRS, lab. GeoRessources, UMR 7359, BP 70239, F- 54506 Vandoeuvre-lès-Nancy cedex (France) bernard.lathuiliere@univ-lorraine.fr text Geodiversitas 2021 2021-11-23 43 22 1187 1291 journal article 10.5252/geodiversitas2021v43a22 1638-9395 5764379 urn:lsid:zoobank.org:pub:6D1643AD-66A5-4678-9397-CE08E610D641 Prismastrea organum n. gen., n. sp. ( Fig. 65 ) urn:lsid:zoobank.org:act: 42293C7A-7574-4594-BECA-57EB2C34910C Nov. gen. 4 sp. 1 – Vasseur 2018: 270-271 , fig. 3.67. TYPE MATERIAL. — Holotype no. CPUN MA0704E6-1. STUDIED SAMPLES. — Four specimens : CPUN MA0704E6-1, MA0704E6-2, MA0704E6-3, MA0704E6-4. FIG. 62. — Isastrea aff. bernardiana (d’Orbigny,1850) : A , distal view of the specimen AM1603A8-2; B , detail in distal view of the specimen Gu1105E3-2; C , detail in distal view of the specimen MA1004E1-5; D , detail in transverse thin section of calices in the specimen AM1603A8-2; E , distal view of the specimen Gu0905E9; F , longitudinal thin section in the specimen Gu1105E3-1; G , detail in transverse thin section of calices in the specimen MA1004E5-7.Scale bars:A, 4 cm; B, 1 cm; C, 5 mm; D, F, G, 4 mm; E, 2 cm. ETYMOLOGY. — From the latin name organum (organ), refers to the typical basalt organ-like shape of the lateral faces of colonies. TYPE HORIZON. — Margaritatus zone ( Upper Pliensbachian ). TYPE LOCALITY. — Koudiat Ech Chehem ( Guigou Plateau ), 33°27’10”N , 4°55’22”W , Morocco . GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Koudiat Ech Chehem ( Guigou plateau, Middle Atlas of Morocco ). FIG. 63. — Montlivaltia fragilis (Fromentel & Ferry, 1866) : A , lateral view of the holotype MNHN.F. M03716 ; B , lateral view of the holotype MNHN.F. M03716 ; C , detail of the septal pennular ornamentation of the holotype MNHN.F. M03716 ; D , detail in lateral distal peripheral view of the septal apparatus of the holotype MNHN.F. M03716 ; E , detail in lateral peripheral view of the holotype MNHN.F. M03716 ; Scale bars: A, B, 2 cm; C, 1 mm; D, 1 cm; E, 2 mm. DESCRIPTION Massive phacelo-cerioid colony with polygonal corallites multiplying by intratentacular budding. Radial elements are subcompact, subconfluent, straight or slightly curved septa, generally free (sometimes joined). Lateral faces of septa hold granules organized in carinae, typically montlivaltid in shape and distribution. Although, the symmetry and regularity of granules on both sides of the septa sometimes differ from the typical model. Distal and inner edges are ornamented with trabecular teeth that sometimes project in the axial zone, producing a parietal papillose columella. No endotheca observed. Wall of unknown nature but precisely delimited and apparently of the same nature as septa. No synapticulae observed. Calicular diameter: 2 to 6 mm – Distance between calices centers: 2 to 4 mm – Number of septa: approximately 86 – Septal density: approximately 18 for 2 mm . SIMILARITIES AND DIFFERENCES Differs from Isastrea by its continuous and well defined wall, from Heterastraea by its montlivaltid septal structure and from Vallimeandropsis that is clearly meandroid.