Nouveaux brachiopodes strophomenatadu dévonien inférieur de l'anti-atlas Occidental, Maroc

Strophomenid brachiopods from the Rhenish Lower Devonian (Germany)

“…As a result, the original diagnosis contains joint characters of the ventral valves of Boucotstrophia and Gigastropheodonta, such as the large and impressed muscle field, but includes also characters of the dorsal valve only developed in the latter genus, such as reduced "socket plates"and elevated muscle platform. Unfortunately, Jahnke's new species "Boucotstrophia" minor, which he erected in the same work, has to be assigned to Gigastropheodonta in accordance to the diagnostic characters of this genus, and the same applies further taxa previously assigned to Boucotstrophia, as well (García-Alcalde 1992, Aït-Malek et al 2000). In my opinion, all described species of Boucotstrophia except for its type species belong to Gigastropheodonta.…”

“…With regard to the genus Boucotstrophia Jahnke, 1981, common in the Seifen fauna, the author has come to the conclusion that its type species B. herculea (Drevermann, 1904) was often taxonomically united with or mistaken for the similar-sized but unrelated "Stropheodonta" gigas (McCoy, 1852) which occurs in the same fauna. In the opinion of the present author, the genus Boucotstrophia has largely been misunderstood by previous workers starting with its original diagnosis (Jahnke 1981) and in the following years, for example by García-Alcalde (1992), Aït-Malek et al (2000) and in the revised Treatise on Invertebrate Palaeontology, Part H (Cocks & Rong 2000). It was necessary to revise the genus and to erect a new genus for the group of "S." gigas.…”

“…The Spanish species shows relatively coarser costellae separating the groups of capillae. Gigastropheodonta gigas differs from G. jahnkei (Aït-Malek, Racheboeuf & Lazreq, 2000) from the upper part of the Mdâouer-el-Kbîr Formation (lowermost Upper Emsian) of the Dra Plains (S Anti-Atlas, Morocco) by much larger shells and relatively wider hinge line with 17 to 27 denticles per flank; the number of denticles reaches only 17 per flank in the Moroccan species; the ventral muscle field of the Rhenish species tends to be more subelliptical or suboval in outline -in contrast to a subtriangular muscle field in G. jahnkei (confirmed by examination of own topo-and stratotypic material). Diagnosis.…”