Paraacanthogyra
Morycowa and Marcopoulou-Diacantoni, 1997, p. 257
Type Species
Paraacanthogyra parnassensis Morycowa and Marcopoulou-Diacantoni, 1997: 257.; Original Designation Morycowa and Marcopoulou-Diacantoni, 1997: 257.
Type Specimen: Holotype; HGPUA 28; Not Traced; Unknown
Type Locality: Albian-Cenomanian of central Greece (Parnassus area)
The holotype of the type species is housed at HGPUA (Athens) under no. 28.
Classification
Diagnosis
Colonial, phaceloid-cerioid, subcerioid-meandroid during the initial stage of septal division. Gemmation intracalicinal, marginal, and/or by septal division. Septa, compact, thick (S1) or thin (S2 and higher), alternating in length. Numerous lonsdaleoid septa present. Columella absent. Wall septothecal-trabecular. Endothecal dissepiments subhorizontal in corallite centre, vesicular in the periphery.
Comparisons
Like Acanthogyra but columella absent and corallites are generally in a greater variety of integration types (phaceloid to cerioid and subcerioid to meandroid integration).
Remarks
Generally, the polyps of Acanthogyra are in cerioid integration. However, studies carried out by Lauxmann (1991, p. 193) on the type material of the type species of Acanthogyra showed that, besides plocoid-meandroid integration types, polyps in phaceloid-fasciculate arrangements are present as well. In addition, Lauxmann cleary pointed out that even in the best preserved polyps in the holotype of the type species, a columella was often not present. On the other hand, in Paraacanthogyra trabecular extentions of axial ends of septa reach the corallite center where they form a segment-like pseudo-columella, thus indicating the close relationship with Acanthogyra. It seems possible that Paraacanthogyra represents a morphological variation of Acanthogyra and might not have the generic independence from the latter.
Distribution
- Southern Europe; Early Cretaceous - Late Cretaceous
Albian-Cenomanian: Greece.This page has been in preparation since 02-Jun-2007 12:36
This version was contributed by Rosemarie Baron-Szabo on 14-Sep-2010 19:50.
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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