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Trismilia

Fromentel, 1861, p. 106

Trismilia Fromentel, 1861, p. 106 is a junior synonym (available and invalid), see Axosmilia Milne Edwards, 1848, p. 467.

The breach of hexameral rule in this group is interpreted rather in terms of growth accident rather than a phylogenetic product justifying a taxonomic unit. Then Trismilia is considered as a form of the group Axosmilia-Pleurosmilia

Type Species

Trismilia triangularis Fromentel, 1861, p. 106; Monotypy

Type Specimen: Syntype; MNHN M03584 and M03193; Verified; Dry Preserved

Type Locality: Kimmeridgian (Upper Jurassic, initially dated as Portlandian) of Mantoche (Haute-Saône, France)

A syntype was figured by Fromentel 1863 pl.1 fig. 6 under the two names T. triangularis and T. portlandica (p. 14). It is a negative. It is figured again with a clear synonymy of the two nominal species A specimen M03193 is also present not so deformed .

Classification

Description

Solitary corallum, infundibuliform. Epitheca ? Corallite outline elliptical. Radial elements compact free bicuneiform straight to slightly curved. Distal edge smooth, inner edge smooth, lateral faces smooth, no palis. Microstructure unknown. Hexameral symmetry not easy to decipher if present, bilateral symmetry disturbed by the abnormal columella. Endotheca not observed, triangular columella, synapticulae absent, wall not directly observed on the mold but probably peripheral and cutting.

Remarks

Two nominal species known (objective synonyms).

Distribution

  • Western Europe; Late Jurassic

This page has been in preparation since 20-Aug-2009 09:35

This version was contributed by Bernard Lathuilière on 18-Dec-2010 10:56.

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


Syntype of Trismilia triangularis type species of the genus
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Syntype of Trismilia triangularis type species of the genus
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Syntype of Trismilia triangularis type species of the genus
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Syntype of Trismilia triangularis type species of the genus
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