Dermosastraea
Beauvais, 1970, p. 1129
Dermosastraea Beauvais, 1970, p. 1129 is a junior synonym (available and invalid), see Isastrea Milne Edwards and Haime, 1851: p. 102.
Type Species
Confusastraea tenuistriata Tomes 1882, p. 423, pl. 18 fig. 11; Original Designation
Type Specimen: Lectotype; NHMUK R.10903; Verified; Dry Preserved
Type Locality: Bajocian of Crickley (South of Cheltenham, Great Britain)
The lectotype is a non sectioned, dry, strongly prepared specimen abusively designated as holotype (ICZN art. 74) It was figured and redescribed in Beauvais 1970, p. 1129, pl. 4 fig. 2
Classification
Description
Massive cerioid corallum with polygonal corallites. Holotheca present. Mode of increase difficult to define, new corallites appear at the edge of the lamellar colony; the lectotype shows a central corallite bigger than others. Radial elements are compact, free or occasionally anastomosed, attenuated, straight to curved septa. Distal edge with small acute regularly spaced teeth, inner edge not visible, lateral faces probably with subvertical carinae, no pali. Microstructure unknown. Hexameral symmetry difficult to decipher if present, bilateral symmetry marked by curvature of septa. Endotheca made of dissepiments , columella absent but inner edges join in depth of the axial zone, synapticulae limited at the wall region, wall similar to typical Isastrea. In some places but not everywhere, a small groove exists between the outer edges of adjacent corallites.
Remarks
The lectotype is strongly mechanically and chemically prepared as often in the material of Crickley described by Tomes. It is highly probable that an important part of the groove around the corallites at the place of the wall is artificial. This character was used by Beauvais to erect Dermosastraea. The second character is the perforation of septa. As the preparation of the holotype often cut the surface at a very short distance of the initial distal edge of septa, we get in many places the feeling of a perforate pattern. Deep sections show compact septa with some well characterised bioerosion borings in some places. In revenge, it is true that I. tenuistriata differs from typical Isastrea by a less regular ornamentation of septa and more numerous anastomoses.
Distribution
- Western Europe; Middle Jurassic
This page has been in preparation since 04-Feb-2010 16:32
This version was contributed by Bernard Lathuilière on 08-Mar-2014 10:46.
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
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