Stylosmilia
Milne Edwards, 1848, p. 468
Type Species
Stylosmilia michelini Milne Edwards and Haime, 1848, p. 468; Monotypy
Type Specimen: Syntype; ?; Lost; Unknown
Type Locality: Coral rag from the department of Doubs (Jura mountains, France)
In the same year 1848, Milne Edwards and Haime gave another subsequent more precise description (p. 275, pl. 6 fig 2, 2a). The locality is also refined (Chaude-Fontaine) and the collection Michelin is mentioned. This genus has been remarkably described by Koby (1881 and 1905).
Classification
Synonyms
Description
Phaceloid corallum with cylindrical corallites. Costae potentially covered by a thin epitheca. Extracalicular increase that preserves the axial symmetry of the septal apparatus of the mother corallite that generally keeps its growth trajectory. Radial elements compact, unequal, rather straight, bicuneiform. Only first cycle septa may join the columella according to a periodic vertical pattern. Distal edge smooth, inner edge with koutaliform auriculae, lateral faces with rare acute granules poorly organised in distribution. Microstructure stylinid. Axial symmetry very stable (hexameral in the type species), bilateral symmetry sometimes visible through the elongation of the styliform columella. Endotheca made of horizontal tabulae, columella styliform, often elongated. No synapticula. No palus. Wall made by external enlargement of septa and addition of thickening deposits.
Comparisons
Stylosmilia differs from Cladophyllia by the mode of increase, the presence of costae, the more stable symmetry of the septal apparatus, the more typical development of auriculae. Stylosmilia is very close of Smilostylia Roniewicz 1966 but differs by the microstructure of the wall septothecal and including mural vertical trabeculae. The columella is a practical mean to distinguish Stylosmilia (styliform more or less elongated) from Rhabdophyllia and Calamophylliopsis (papillose), from Placophyllia (clearly lamellar) and from Proaplophyllia (absent). Pleurophyllia is very different because of its cardinal septum.
Remarks
Stylosmilia is a widely distributed genus 29 nominal species have been created rightly or wrongly in Jurassic, 14 in Cretaceous (Löser 2000)
This page has been in preparation since 20-Aug-2009 09:16
This version was contributed by Bernard Lathuilière on 28-May-2016 09:59.
Page authors are: Ewa Roniewicz 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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