Systematics, palaeoecology and taphonomy of Turonian oysters from the northern Gabon Coastal Basin Author Musavu Moussavou, Benjamin text Geodiversitas 2017 2017-06-30 39 2 213 224 journal article 31257 10.5252/g2017n2a3 f9e855d7-6356-4312-8dbe-c3dd884d6277 1069848 F4D33955-5823-49E9-BC9A-26DFB03038A7 Gyrostrea sp. A ( Fig. 3 A) MATERIAL . — 1 specimen (MDG/LBV/Lm-13). OCCURRENCE . — Turonian of Gabon (this study). FIG. 4. — A -D , Ostrea sp. D: A , B , MDG/LBV/Lm-33.1; C , D , MDG/LBV/Lm-33.2; E , Ostrea sp. C MDG/LBV/Lm-32.1; F , Gyrostrea sp. B MDG/LBV/Lm-14; G -N , Gyrostrea delettrei (Coquand, 1862); G , H , MDG/LBV/Lm-12.1; I , J , MDG/LBV/Lm-12.2; K , L , MDG/LBV/Lm-12.3, M-N. MDG/LBV/Lm-12.4; O -R , Ostrea sp. B; O , P , MDG/LBV/Lm-31.1; Q , R , MDG/LBV/Lm-31.2; S -U , Ostrea sp. A, S-T. MDG/LBV/Lm-15.1; U , MDG/LBV/Lm-15.2. Scale bar: 1 cm. DESCRIPTION Shell, represented by LV, is medium, inequilateral, elongated to elliptical shape in outline. Anterior and posterior margin are curved giving semicircular shape of shell. Attachment area is small. Surface rough with growth squamae and few rough rounded irregular ribs well separated from each other. REMARKS This species differs to Gyrostrea delettrei ( Coquand, 1862 ) in having small irregular ribs.