Heterastraea
Tomes, 1888, p. 210
Type Species
Isastrea tomesii Duncan 1868, p. 46, pl. 15, fig. 20; Subsequent Designation Vaughan and Wells, 1943
Type Specimen: Neotype; NHMUK R 11850; Verified; Dry Preserved
Type Locality: Hettangian (Lower Jurassic) of Long Coppice (near Binton, Warwickshire, Great Britain)
The type specimen composed of one dry sectioned sample and two thin sections was figured and redescribed in Beauvais 1976 p. 59 pl. 12 fig. 6; pl. 13 fig. 1 and text fig 21-25. The status of the type-specimen is unclear. Duncan described and figured something which does not look like the sample R 11850 (British Museum) labelled as the holotype and also used by L. Beauvais 1976 as the holotype. In 1878 Tomes (p.184-185) speaks of "the type specimen" and speaks of "the specimen" (singular) described by Duncan. Ten years later he mentioned that "the type of this species is so indifferently preserved that were it not a well marked species it would be practically useless for comparison". Then obviously the so-called holotype evoked by the label and by Beauvais 1976 is not the holotype by monotypy we could expect. Nevertheless it is an excellently preserved sample coming from the Tomes' collection already used as a type specimen and for practical reason of stability, Lathuilière, Charbonnier and Pacaud (2017) designated it as the neotype.
Classification
Description
Massive cerioid corallum with polygonal infundibuliform corallites. No holotheca. Intracalicinal septal increase. Radial elements are septa s.s. compact, mostly free, anastomosing occasionally in the center, of a rather constant thickness, straight or curved, sometimes lonsdaleoid. Often big lonely or scarce teeth at the distal inner edge. Lateral faces are smooth or with subvertical ridges. Microstructure non trabecular. No real pali but often these teeth. Hexameral symmetry cannot be deciphered, bilateral symmetry linked with intracalicular increase and characterised by elongation of calices and curvature of septa. Abundant endotheca made of tabulae, tabuloid and vesicular dissepiments forming a distally concave floor in the centers, Axial zone with a poorly defined fossa or occupied by anastomosing septa. Synapticulae absent. Wall well defined with a cutting edge, often structured with a median line and in continuity with septa.
Remarks
13 nominal species in Early Jurassic. In a recent paper Gretz et al (2013)include two subgenera within the genus Lepidophyllia: Lepidophyllia and Heterastraea.
Distribution
- Western Europe; Early Jurassic
- Southern Europe; Early Jurassic
This page has been in preparation since 18-Aug-2009 17:57
This version was contributed by Bernard Lathuilière on 21-Jul-2017 14:52.
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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