Proleptophyllia multiradiata Beauvais, 1986

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1225-1228

Proleptophyllia multiradiata Beauvais, 1986

( Fig. 25 )

Proleptophyllia multiradiata Beauvais, 1986: 52 , pl. 13, fig. 4, pl. 14, fig. 4, 5. — Vasseur 2018: 300-301, fig. 3.79.

? Montlivaltia spiculata Fromentel & Ferry, 1866: 142 , pl. 23, fig. 2.

? Procyclolites spiculata – Alloiteau 1957: 106, pl. 5, fig. 19.

Proleptophyllia rejuvenescens Beauvais, 1986: 53 , pl. 14, fig. 1, texte-fig. 31.

Proleptophyllia subcylindrica Beauvais, 1986: 53 , pl. 15, fig. 2.

? Myriophyllum constrictum Beauvais, 1986: 36 , pl. 8, fig. 2 and txt-fig. 24.

TYPE MATERIAL. — Holotype: MNHN.F.R11638 (coll. Menchikoff MD 7), original designation; paratypes: 32 specimens (coll. Menchikoff MD 8 [eight specimens, MNHN.F.A32018], MD 29, MD 34 [22 specimens, MNHN.F. A32013 ]). TYPE HORIZON. — Domerian (Upper Pliensbachian ). TYPE LOCALITY. — Beni Tadjit ( Morocco). STUDIED SAMPLES. — 22 specimens: MNHN.F.R11638, R11639, MNHN.F.R11640, R11642, R11646, A32013 , A32018, A32019, MNHN.F.A32020, A32022, CPUN AM16162-2,CPUN AM16178-4. GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Pliensbachian of Beni Tadjit and Amellagou ( Morocco).

DESCRIPTION

Fungiform to discoid solitary corallum subcylindrical in young stages, sometimes showing successive rejuvenescences. Pedunculate, flat lower face is layered by a possible epitheca with concentric wrinkles, which reveals sometimes fine, equal costae, very close and equidistant. The calice is circular to elliptic in outline, sometimes convex, sometimes infundibuliform or flat, with a small circular to elliptic fossa of variable depth in the axial zone in which septa plunge. Radial elements are straight, subcompact, free or joined costosepta of which fenestrate distal ornamentation reveals a pennular growth pattern with meniana subsequently embedded by stereome deposits. These deposits sometimes also unit two or three neighbouring septa, making difficult the appreciation of the number and density of septa in some samples. Distal edge with round teeth quite homogeneous on one septum but with a diameter that varies from one cycle of septa to another. Trabeculae are externally subvertical and tend to lie down in the internal part of septa, forming a papillose parietal columella. No wall observed. Synapticulae present and possibly dissepiments too. Bilateral symmetry appears when the calice is elongated.

Calicular diameter: 9.4 to 35 mm – Number of apparent septa: 80 to 240 – Corallite height without rejuvenescense: 9 to 11 mm – Septal density: 8 to 20 for 5 mm – Trabecular density: 5 to 11 for 2 mm.

SIMILARITIES AND DIFFERENCES

As P. rejuvenescens and P. multiradiata , erected and distinguished by Beauvais (1986), come from the same locality

and differ only by the fact that P. rejuvenescens shows rejuvenescences, they are interpreted here as a case of intraspecific variability due to ontogenetical contingencies. On the other hand, important rates of morphologic variability in shapes and dimensions have been measured among P. multiradiata Beauvais, 1986 , P.rejuvenescens Beauvais, 1986 and P. subcylindrica Beauvais, 1986 . As statistical analysis did not distinguish them, we merged these three species under one single species (see figures 47.G, H). A synonymy with Montlivaltia spiculata Fromentel & Ferry, 1866 and Procyclolites spiculata Alloiteau, 1957 is suspected but cannot be comfirmed regarding to the type material of these taxa.

Figures

FIG. 25. — Proleptophyllia multiradiata Beauvais, 1986: A, upper and lower faces of one of the specimens MNHN.F.A32020 (batch). Scale: 1 cm and 5 B, detail in transverse thin section of the septal structure of P. multiradiata (coll. MNHN); C, upper and lower faces of one sample of P. multiradiata (Coll. MNHN); D, detail in longitudinal thin section of the septal structure of P. multiradiata (coll. MNHN); E, detail of the distally fenestrate pennular structure of septa; F, rejuvenescent specimen MNHN.F.R11642; G, graph presenting septal density as a function of the great diameter (Gd) of calices. The different symbols represent the different nominal species created by L. Beauvais (1986): black dots, Proleptophyllia multiradiata; red cross, P. rejuvenescens Beauvais, 1986; blue rhombs, P. subcylindrica; H, graph presenting the apparent number of septa as a function of the great diameter (Gd) of calices. Symbols have the same meaning as in Fig. 25G. Scale bars: A, 1 cm and 5 mm; B, 1.5 mm; C, 1 cm; D, 2 mm; E, 1 mm; F, 5 mm.