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Margarogyra

Roniewicz, 2011, p. 410

Type Species

Margarogyra hirsuta Roniewicz, 2011, p. 410, fig. 3B1-3B5, 3D; Original Designation

Type Specimen: Holotype; GBA 2009/019/9; Verified; Dry Preserved

Type Locality: Site north-west of Feisterscharte, Dachstein Plateau, Northern Calcareous Alps, Epigondolelle quadrata Conodont Zone, Lacian, Early Norian, Late Triassic

Classification

Diagnosis

Thamnasterioid colony with circumoral budding. Central corallite large, with up to 90 septa (sometimes 2-3 central corallites) encircled by smaller corallites with up to 40 septa. Axial pits small and empty. Septal apparatus composed of septa from two to four size orders. Distally, septa S1 and S2 subequal in height and the highest of all other septa, have thick, rounded margins covered, like other septal surface, with minute granulations. Septal microstructural elements, in the form of long, fibre portions, emerge on septal faces as densely packed, sharply-ended granulations having 50-75 um in diameter. Dissepiments vesicular, abundant.

Comparisons

In thamnasterioid relationships of corallites and in corallite dimensions the genus resembles North American Campesteria prolixia Carruthers and Stanley, 2008,. However, Campesteria seems to have a different microstructure, as its distal septal borders show thick ornamentation resembling trabecular tips.

Remarks

Two species were described up to now, the Alpine Early Norian M. hirsuta and American species from the Late Carnian-Early Norian from Nevada, M. silberlingi Roniewicz and Stanley, 2013.

Distribution

  • Southern Europe; Late Triassic
  • North America; Late Triassic

This page has been in preparation since 22-Aug-2013 16:46

This version was contributed by Ken Johnson on 22-Aug-2013 16:49.

Page authors are: Ewa Roniewicz. Please contact the editor if you would like to contribute to the diagnosis of this taxon.

The editor is: Ewa Roniewicz

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