Hispaniastraea murciana Turnšek & Geyer, 1975

Vasseur, Raphaël & Lathuilière, Bernard, 2021, Pliensbachian corals from the Western Tethys, Geodiversitas 43 (22), pp. 1187-1291 : 1231

Hispaniastraea murciana Turnšek & Geyer, 1975

( Fig. 29 )

Hispaniastraea murciana Turnšek & Geyer in Turnšek, Seyfried & Geyer, 1975: 138, pl. 20, figs. 1-2, pl. 21,figs. 1-2. — Vasseur 2018: 216-217, fig. 3.46. — Boivin et al. 2019: fig. 4-5 cum syn.

Chaetetes (Pseudoseptifer) murciana – Beauvais 1980: 30, pl. 3, fig. 2.

TYPE MATERIAL. — Holotype: colony no. 33 (original designation); Turnšek et al. 1975: 22, pl. 20-21, from collection Seyfried reposited in Departamento de Paleontología of the University of Granada ( UG), Spain. TYPE HORIZON. — Upper Sinemurian-Lower Pliensbachian , Lower Jurassic. TYPE LOCALITY. — Zarcilla de Ramos (Province of Murcia, Spain). STUDIED SAMPLES. — Seven specimens: MNHN.F.LB5374, CPUN DA0106E2-4, CPUN 2303 A1-6, CPUN AM16160-2, CPUN DA2905E1-2, CPUN DA2905E2-2, CPUNDA3105 E3-1. GEOGRAPHIC AND STRATIGRAPHIC RANGES. — Sinemurian of Murcia ( Spain) and Languedoc ( France), Pliensbachian of Calabria ( Italy) and Pliensbachian to Lower Toarcian (pre-TOAE) of High Atlas and Middle Atlas of Morocco.

DESCRIPTION (in collaboration with S. Boivin)

Cerioid massive, lamellar or ramose colony. Subcircular to polygonal corallites sometimes strongly distorted, particularly in the middle of the branches. The septal apparatus is characterized by one major septum that dominates in width and thickness. It is straight or curved, compact, ornamented only by periodic auriculae along its inner edge. The auriculae are subcircular in transverse section (they fill up to 3/4 of the lumen surface) and reveal a horizontally elongated rhombic shape or a platelike shape with rims turned upward in longitudinal section perpendicular to the mid-septal plan. The inner edge of the major septum is thus enlarged at each auricula and narrower and rounded between successive auriculae, conferring to the lumen a characteristic horseshoe shape. Minor septa are short, compact, rounded or sharp and generally restricted within the wall that makes them sometimes undistinguishable. The inner edge of septa is covered of granules that alternate with the auriculae of the major septum. In some parts of the colonies where geometrical constraints of construction are weak, all the major septa of the neighbouring corallites are oriented in the same direction. Thin, concave (in distal view) tabulae can sometimes be observed. Microstructure not preserved. Two different modes of budding coexist in the colonies: extracalicular budding and intracalicular septal budding. Many heterogeneously distributed intercalicular canals have been observed. These canals are restricted to some parts of the colonies and their origin is still unknown. The hypothesis of an association between non-corals organisms is considered.

Great diameter of the lumen: 0.46 to 1.95 mm – Small diameter of the lumen: 0.14 to 1.44 mm – Thickness of the wall: 0.09 to 0.84 mm – Distance between calices centers: 0.49 to 2.10 mm – Length of major septa: 0.11 to 0.99 mm – Thickness of major septa: 0.05 to 0.57 mm – Number of apparent septa: 1 to 12.

REMARKS

This taxon is morphologically close to a chaetetid sponge group that belongs to the sug-genus Chaetetes (Pseudoseptifer) Fischer, 1970 but differs from the latter by the presence of auriculae on the major septum, intercalicular canals and a serrated aspect of the wall due to abortive septa (see Boivin et al. 2019).

Figures

FIG. 29. — Hispaniastraea murciana Turnšek & Geyer,1975:A, distal view of the specimen MNHN.F.LB5374; B, ramose specimen pictured in the field (Dades Valley, Morocco,31°33’43”N, 5°54’13”W); C, massive specimen pictured in the field (Vallone del Gardo,Calabria,Italy,39°27’51”N, 16°47’26”E); D, longitudinal thin section of the specimen CPUN DA2905E1-2; E, transverse thin section of the specimen CPUN AM16160-2. Scale bars: A, 1 cm; B, 4 cm; C, 2 cm; D, 2 mm;E, 5 mm.