Plesiomontlivaltia
Alloiteau, 1957, p. 114
Alloiteau (1957, p. 114) created the subgenus Plesiomontlivaltia using the species Montlivaltia inflata as the type species. In addition, however, he grouped the same species with Paramontlivaltia Alloiteau (1957, p. 110)
Type Species
Montlivaltia inflata Fromentel, 1861, p. 118-119; Original Designation
Type Specimen: Lectotype; MNHN R10919; Verified; Dry Preserved
Type Locality: Oxfordian from Champlitte (France)
Classification
Description
Solitary corallum. Elliptical calice. Deep calicular platform. Radial elements are compact, free, bicuneiform, straight to curved costosepta. Ornamentation weak but not satisfactorily observable on the strongly silicified lectotype. Radial symmetry possibly hexameral. Bilateral symmetry characterized by the elongated fossa, the elliptical shape of the corallite and the torsion of septa. Endotheca made of vesicular dissepiments sloping down from the parathecal wall to the center of the corallite.
Comparisons
Differs from Montlivaltia (Montlivaltia) by the septal ornamentation
Remarks
Three nominal species were reported (all three by Alloiteau). This subgenus and the double assignation of the type-species to Plesiomontlivaltia (as a subgenus of Montlivaltia) and to Paramontlivaltia (placed in the Smilotrochiidae) demonstrates how the variability of the septal ornamentation in Montlivaltia has never been studied thoroughly enough. The potential use of this subgenus is subordinate to a populational study of intraspecific variability in Montlivaltia
Distribution
- Western Europe; Late Jurassic
- Eastern Europe; Late Jurassic
This page has been in preparation since 19-Aug-2009 17:02
This version was contributed by Bernard Lathuilière on 27-May-2017 09:58.
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
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