Thamnocoenia

Tomes, 1885, p. 176

Type Species

Thamnocoenia oolitica Tomes 1885, p. 177, pl. 5 fig. 5-8; Monotypy

Type Specimen: Holotype; NHMUK R 8489; Verified; Dry Preserved

Type Locality: Bathonian (Middle Jurassic) of Comb-Down (near Bath Great Britain)

The holotype by monotypy was figured and redescribed in Beauvais (1970), p. 1120, pl. 4 fig. 4.

Description

Dendroid corallum. Subcylindrical corallites. Calices infundibuliform, cutting calicular edge. Thin subequal costae locally covered by an epitheca. Extracalicinal increase producing branches with a wide angle of divergence. Radial elements are compact free attenuated or swollen at the inner edge, straight to sinuous costosepta. Distal edge smooth, inner edge often swollen, lateral faces not ornamented, no pali (but some rare mimetic situations for some particular septa). Microstructure unknown. Clear hexameral symmetry. Bilateral symmetry marked in some calices by the eccentricity of the fossa. Endotheca made of dissepiments (a good longitudinal section is missing to know how it is structured), columella absent but a rather well defined fossa, synapticulae absent, wall of unknown nature.

Comparisons

Thamnocoenia seems to be very close of Goniocora that has a columella.

Remarks

One nominal species, and one specimen known. The granulations evoked by Beauvais size in the range of diagenetic calcite crystals that constitute the fossil. There are not taken into account. There is no clear evidence such as auricules to assign Thamnocoenia to Stylinidae.

Distribution

• Western Europe; Middle Jurassic

This page has been in preparation since 20-Aug-2009 09:21

This version was contributed by Bernard Lathuilière on 05-Feb-2010 14:38.

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