Montlivaltia
Lamouroux, 1821, p. 78
Type Species
Montlivaltia caryophyllata Lamouroux, 1821, p. 78, tab. 79, fig. 8, 9, 10; Monotypy
Type Specimen: Syntype; ; Not Traced; Unknown
Type Locality: « Calcaire à polypiers des environs de Caen » (Probably Bathonian, near Caen, Normandy ; France)
Classification
Synonyms
Description
Solitary corallum discoid to cylindroid. Epitheca s.l. plicate, made of exothecal dissepiments that leave the top of radial elements uncovered. Costae most frequently covered in their proximal part. Corallite circular or slightly elliptical. Radial elements are compact free bicuneiform unequal costo-septae. They are straight or curved according to a bilateral arrangement. Distal and inner edge ornamented of sharp regular teeth (often triangular or trifid in shape), lateral faces ornamented of regularly distributed carinae perpendicular to the distal edge. Palis absent. Microstructure montlivaltid. Hexameral symmetry not always easy to decipher, bilateral symmetry often marked by the curvature of septa and a slight elongation of the central fossa. Endotheca abundant made of vesicular dissepiments , columella absent but large septa can join in depth. Synapticulae absent. Wall parathecal or paraseptothecal, made by the thickening deposits of septa in continuity with dissepiments.
Comparisons
Montlivaltia has been confused with many other solitary corals that have different microstructure and microarchitecture (for instance Haimeicyclus, Stylophyllopsis, Palaeophyllia….) Among solitary corals that have the same microstructure Montlivaltia differs from Cyathophylliopsis and Kobyphyllia by the absence of columella. Gonioseris has the same microstructure but a very special outline, Montlivaltiopsis and Stereophyllia are probably junior synonyms, Aulophyllia could be also a synonym ? Neuquinosmilia possibly ranges within the variability of Montlivaltia but seems to have a special microstructure producing secondary trabecular axes in various directions. Amblophyllia is a morphogenus name for a Montlivaltia that becomes colonial (see this genus).
Remarks
Montlivaltia was well described by Lambelet (1968) and by Gill and Lafuste (1971). Relationships with colonial montlivaltids are investigated in Lathuilière (1976a, b). Many Jurassic nominal species of Montlivaltiahave been created (260 according to Lathuilière 1989) and 74 Cretaceous species according to Löser (2002). All these citations obviously need a revision.
This page has been in preparation since 19-Aug-2009 16:02
This version was contributed by Bernard Lathuilière on 27-May-2017 09:54.
Page authors are: Bernard Lathuilière Ewa Roniewicz. 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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