Amphiastrea
Etallon, 1859, p. 500/100
Type Species
Amphiastrea basaltiformis Etallon, 1859 p.501; Monotypy
Type Specimen: Holotype; ; Not Traced; Unknown
Type Locality: "Dicératien" (Kimmeridgian) Valfin, France.
Good sections can be found for instance in Beauvais,1964 and Eliasova,1975, good microstructural illustrations are given in Kolodziej, 1995
Classification
Description
Massive cerioid colony. Strictly polygonal calices. Pachytheca with a median line (the wall is not really shared between two adjacent corallites as usually in Scleractinia; for this reason it is sometimes described as phaceloid). Marginarium. Taschenknospung. Radial elements are smooth, free or anastomosted septa s.s, flexuous to straight made of small numerous simple trabecules in series. Lonsdaleoid septa present. Septal apparatus with a strong bilateral symmetry. A septum thicker than others in some species. Eccentric axial pit. Peripheral steeply inclined vesicular dissepiments. Cellular central dissepiments controversial. Striated epitheca present around each corallite. No peritheca, no synapticula, no palus, no columella.
Comparisons
Oyonnaxastraea has a thicker wall and an axially thickened major septum but could range in the variability of Amphiastrea. Acanthogyra shows strong granules on lateral faces of septa and a septal budding. Heterastraea has large teeth on inner-distal edge of septa.
Remarks
12 Jurassic and 16 Cretaceous nominal species
This page has been in preparation since 21-Aug-2009 17:01
This version was contributed by Bernard Lathuilière on 15-Feb-2010 16:26.
Page authors are: Bernard Lathuilière. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Bernard Lathuilière
|