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Anisastraea

Alloiteau, 1957, p. 163

Anisastraea Alloiteau, 1957, p. 163 is a junior synonym (available and invalid), see Meandrastrea Orbigny, 1849, p. 10.

Type Species

Astrea lamellosissima Michelin, 1841, p. 23, pl. 6, fig. 6; Original Designation Alloiteau, 1957, p. 163

Type Specimen: Holotype; ; Not Traced; Unknown

Type Locality: Upper Turonian of France (Uchaux)

The holotype of the type species is housed at MNHN under Mo0484.

Classification

Diagnosis

The genus Anisastraea Alloiteau, 1957 is characterized by a massive corallum; corallites arranged in (subthamnasterioid-) meandroid series; corallite centers distinct, sometimes connected by lamellar linkages; gemmation intracalicinal; costo-septa compact, confluent and non-confluent, dentate laterally and marginally, sometimes forming vertical carines; costae well-developed or nearly completely reduced; columella is lamellar or consists of irregular or elongate trabecular segments; wall parathecal; endothecal dissepiments numerous.

Comparisons

In contrast to the original documentation by Alloiteau (1941, p. 31, pl. 11, fig. 4, pl. 12, figs 4-5), the genus Anisastraea also shows corallites that are connected by lamellar linkages; the development of a variety of columellar types (various parietal structures in addition to the lamellar kind), and occasional carinate septal ornamentations. Because the combination of all of these characteristics is typical of the genus Meandrastraea d’Orbigny, their synonymy is suggested.

Remarks

Milne Edwards and Haime (1851, p. 103) grouped the form Astrea lamellosissima Michelin with the genus Isastrea. Later, Alloiteau (1941, p. 31) provionally assigned the taxon Astrea lamellosissima Michelin to the genus Reussastraea de Fromentel, 1886 (non d'Achiardi, 1875). Besides the fact that de Fromentel's genus represents a junior homonym of d'Archiardi's taxon, Alloiteau (1941) already pointed out that the genus Reussastraea de Fromentel was only mentioned by de Fromentel (1886, p. 562, table) without giving any description of this genus other than that it belonged to the Family Astrees Milne Edwards and Haime, 1859, and that it had a lamellar columella. In addition, Alloiteau stated that, by the nature of its walls, the form Astrea lamellosissima Michelin differed from both the Astrea-concept of Milne Edwards and Haime and the genus Isastrea. Later, after re-examination of the type material, Alloiteau (1957, p. 162-163) came to the conclusion that the taxon Astrea lamellosissima Michelin belonged to the Family Dendrogyridae and created the new genus Anisastrea using Michelin's taxon as the type species. However, re-investigation by Baron-Szabo (2010, unpublished data) revealed that by the presence of occasional carines, the genus Anisastraea showed close affinities to the montlivaltiids (see discussion above).

Distribution

  • Central Europe; Late Cretaceous

This page has been in preparation since 12-Aug-2010 20:02

This version was contributed by Rosemarie Baron-Szabo on 17-May-2011 21:33.

Page authors are: Rosemarie Baron-Szabo. Please contact the editor if you would like to contribute to the diagnosis of this taxon.

The editor is: Rosemarie Baron-Szabo

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