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Trochoplegma

Gregory, 1900, p. 180

Type Species

Trochoplegma tenuilamellosa Gregory 1900, p.180, pl. 23, fig. 3-10, pl.2A fig. 8; Original Designation

Type Specimen: Syntype; GSI N° 6754; Verified; Dry Preserved

Type Locality: Middle Bathonian, Coral Bed, Jumara Dome, Kachchh, India

Syntypes described by Gregory (1900: 180); topotypes are described by Beauvais (1978: 61) and best illustrated by Pandey and Fürsich 1993: 29, Pl. 8, figs. 11-16; Pandey et al. 1999: 1017.

Classification

Diagnosis

Corallum fixed fungiform , generally solitary but occasionally colonial with a few rudimentary corallites, budding circumoral. Upper surface convex, calicular fossa slightly elongated. Septa flexuous, anastomosing, fenestrate. Trabeculae pennular, pennular margin finely denticulate; maenianae continuous to discontinuous. Synapticulae common. Epitheca thin.

Comparisons

This genus has close affinity with some of the microsolenids, likeTrocharea Etallon 1864, Chomatoseris Thomas 1935, Trochoplegmopsis Roniewicz 1976 and Dimorpharaea de Fromentel 1861. The trabeculae and septa are thinner and pennulae are much more pronounced in Trochoplegma than in Trochraea(Pandey et al. (1999: 1017), Trochoplegmopsis is characterized by papillose columella (Roniewicz (1976: 95), Chomatoseris is free living and without epitheca (Pandey and Fürsich 2003: 111), Dimorpharaea is colonial coral with many corallites but lesser teeth density along the pennular margin (Pandey et al. 2000: 23, Table 3,).

Remarks

Pandey and Fürsich (1993: 28-29), based on their own observation and those of studied by Gregory (1900: 179), Vaughan and Wells (1943: 148), Alloiteau (1952: 669), Wells (1956: F391), Flügel (1966) and Beauvais (1964: 228; 1972: 69-70; 1978), critically examined the taxonomic status of the genus Trochoplegma Gregory (1900) and found it to be a valid genus (Pandey et al. 2000: 22). Among the six Jurassic nominal species that were assigned to Trochoplegma, probably few really belong to this genus.

Distribution

  • Central Asia, South Asia; Early Jurassic - Middle Jurassic
From Coral Bed (Jhurio Formation), Jumara Dome (Middle Bathonian) of the Kachchh Baisn (India), Badamu Formation (Toarcian) at Kuh-e-Shisui and the Baghamshah Formation (Lower Callovian) at Kuh-e-Echellon (Iran), Mughanniyya Formation (Callovian) of Tal el Dhahb and east of Dier-Alla (Jordan).

This page has been in preparation since 15-May-2009 17:05

This version was contributed by Bernard Lathuilière on 04-Dec-2009 10:16.

Page authors are: Dhirendra Kumar Pandey. 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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