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Castiglionastrea

Gill, Santantonio and Lathuilière, 2004, p. 329

available name but a junior synonym of Acanthogyra

Type Species

Castiglionastrea tenuisepta Gill, Santantonio and Lathuilière 2004 p.329, pl. 2; Original Designation

Type Specimen: Holotype; MPUR NS 83.1; Verified; Dry Preserved

Type Locality: From Castiglione (near Monte Lacerone), Bugarone superiore Formation. (probable Kimmeridgian)

One sectioned specimen in 3 big pieces and a small one, 16 thin sections, 2 acetate peels.

Description

Massive colonial corallum. Cerioid structure with clearly polygonal and closely packed corallites. Septal budding. Theca generally straight (rarely rounded), made of a central midseptal zone covered by a narrow pale layer. Midseptal zone built with closely packed trabeculae which must have a horizontal component in their direction as indicated by some granules which emerge from the covering layer. Number of trabeculae in the wall: 9–10 per 1 mm. Laminar layers seem to thicken the wall, rendering its surface flat with minute sharp endings of the finger-like projections which protrude out over the surface of the wall. The radial elements are compact septa s.s. arranged in a radial symmetry. First cycle composed of equally thick and long septa, two to nine according to the septal budding process. Septa often sinuous, ornamented by strong irregular granules and anastomosed at their inner edge. In contrast, minor septa extremely thin, less sinuous and poorly ornamented. Along the wall, tiny projections of rudimentary septa may appear here and there. The minor septa emerge from the wall and are probably in continuity with the trabecular projections of the wall. Nevertheless, in few cases, they initiate from the surface of a dissepiment which covers a calicular corner (lonsdaleoid septa). Septal structure with a dark median band running along the septum having its origin in the dark trabecular median structure of the wall. It is probably composed of small joined trabeculae. This continuous or discontinuous dark band sends lateral offsets (secondary axes) to form septal spines. Dissepiments abundantly distributed, vesicular or tabular and extremely slender. In cross section, they often join with inner ends of major septa, which in some cases may give an image of a slack columella. They also form rings at the middle of the calicular radius. Small dissepiments often connect minor septa near the wall. In longitudinal section, vesicular dissepiments are seen piled along the wall. Horizontal or inclined dissepimental sections appear between septa,

Comparisons

The closest coral genus is Amphiastrea, as recently revised by Kolodziej (1995), but the major septa exhibit strong granules, while septa are smooth in Amphiastrea. Additionaly, septal budding is not known in Amphiastreidae. These characters imply a classification within Heterocoeniidae.

Remarks

The holotype is the only specimen known, but the quality of the preservation and the very original characters justify the genus.

Distribution

  • Southern Europe; Late Jurassic
Probable Kimmeridgian from Italia

This page has been in preparation since 07-May-2009 09:50

This version was contributed by Bernard Lathuilière on 06-Feb-2010 09:44.

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


Holotype of Castiglionastrea tenuisepta type species of the genus
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Holotype of Castiglionastrea tenuisepta type species of the genus
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Holotype of Castiglionastrea tenuisepta type species of the genus
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Holotype of Castiglionastrea tenuisepta type species of the genus
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