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Thamnoseris

Fromentel, 1861, p. 241

Type Species

Thamnoseris incrustans Fromentel, 1861, p. 241; Monotypy

Type Specimen: Holotype; ?; Lost; Unknown

Type Locality: Callovian (Middle Jurassic) of Chaumont (Saint Claude), in French Jura

The type-species was never figured, but the genus is widely used for other species. Probably because the original description by Fromentel was based on a sample provided by Etallon, Koby unfortunately attributed the authorship of the genus to Etallon. Subsequently, Alloiteau (1952), followed by Beauvais (1964) and Roniewicz (1979) among others (but not Wells 1986) considered erroneously not only Etallon as the author of the genus but also T. frotei Etallon as the type-species.

Classification

Description

According to Fromentel (1861), Massive thamnasterioid corallum. Thin epitheca. Radial elements are thick, confluent subequal straight biseptal sheets. S3 and S2 anastomosed to higher ranking septa. Narrow papillar columella. According to Koby (1887, 1889), Massive thamnasterioid corallum. Septa subcompact (irregular circular to elliptic pores at the inner edge). Inner edge jagged in strips that form the papillose columella.. Lateral faces covered of tubercules and points that join neighbouring septa (Koby’s pseudosynapticules, that are probably pennules). Thin vesiculose dissepiments. Distal inner edge jagged in styliform points, distal outer edge simply granulated . Septa abundantly anastomose each other without rules. According to Roniewicz (1979), Thamnasterioid to cerioid. Irregularly porous, confluent anastomosing septa, trabecular lobes forming a papillar columella; vesicular endotheca, synapticulotheca commonly developed; trabecules with flattened lateral processes; gemmation extratentacular.

Remarks

16 nominal species cited in Jurassic (Lathuilière 1989) and 9 in Cretaceous (Loser 2000). Considering that (1) the type material is lost, (2) no material of the type species is available (3) Most of the literature is based on the Koby’s concept of the genus it is suggested to ask the ICZN to change the type-species into T. frotei Etallon.

Distribution

  • Western Europe, Southern Europe, Central Europe, Eastern Europe, North Africa, Subsaharan Africa, Central Asia, South Asia, East Asia, Central America, West Asia; Middle Jurassic - Late Cretaceous

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

This version was contributed by Bernard Lathuilière on 01-Oct-2011 10:31.

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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