Hexapetalum
Eliasova, 1975, p.17
Eliasova initially placed Hexapetalum in Amphiastraeidae and subsequently in Hexapetalidae (Eliasova 1976). Beauvais and Bernier (1981), then Stolarski and Russo (2001) placed the genus again in the Amphiastraeidae. Kolodziej (2003) moved the genus to the family Heterocoeniidae.
Type Species
Hexapetalum impium Eliášová, 1975, p. 17, pl. 9 fig. 2, pl. 12 fig. 1,2, text-fig.11; Original Designation
Type Specimen: Holotype; ÚÚG HF 250; Verified; Unknown
Type Locality: Tithonian (Upper Jurassic)-Berriasian (Lower Cretaceous) of Stramberk (Czech Republic)
Paratypes exist (HF 267 with thin sections n° 86495-86494. A complementary description is given in Eliášová, 1976 p. 361
Classification
Description
Corallum phaceloid. Corallites hexagonal with rounded outlines or subcircular. Wall fibrous, pachythecal, no costae. Intramural increase through circumoral, hexameral budding, or fissiparous, neotenic division. Radial elements compact, free septa s. s., ordered following bilateral – radial symmetry into petaloid sectors. Septal apparatus differentiated into six septa complex in structure, originated from invagination of the wall, and filiform septal blades developed on the inner margin of the former, and on the inner surfaces of the wall and/or dissepiments. Endotheca made of spaced, subtabular dissepiments; lonsdaleoid dissepiments present. No columella, no synapticulae, no paliform lobes.
Remarks
Three species are known in Jurassic and one in Cretaceous
Distribution
- Western Europe, Central Europe, Eastern Europe, South Asia; Late Jurassic - Early Cretaceous
This page has been in preparation since 18-Aug-2009 17:58
This version was contributed by Bernard Lathuilière on 02-Jun-2011 09:33.
Page authors are: Bernard Lathuilière Helena Eliášová Ewa Roniewicz. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Bernard Lathuilière
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