pdfs:
Pt. 1 http://www.ville-ge.ch/mhng/paleo/paleo-pdf/27-2/pal-27-2-14-1.pdf
Pt. 2 http://www.ville-ge.ch/mhng/paleo/paleo-pdf/27-2/pal-27-2-14-2.pdf
Pt. 3 http://www.ville-ge.ch/mhng/paleo/paleo-pdf/27-2/pal-27-2-14-3.pdf

Abstract: Very important collections of Middle Jurassic Brachiopods have been accomplished these last thirty years in many localities of Morocco and Western Algeria at the time of common field-trips and/or for the realization of thesis. Our first species determinations given to the different authors and published in their papers and thesis have been revisited here. The studied material includes 8180 specimens, 3120 of which have been measured for biometrical studies and the description of species with their variability. The present paleontological study deals with Rhynchonellida (41 species), Terebratulidina (42 species) and Terebratellidina (10 species), all referred to 40 genera. The evidence of internal characters with the serial sections method has allowed to justify or to modify the previous generic referrings of the species. On a paleontological plane, a new definition of the species Burmirhynchia athiensis warrants to precise its vertical extension (Parkinsoni and Zigzag Zones of Late Bajocian and Early Bathonian) and to give a better discrimination with Burmirhynchia termierae (Humphriesianum and Niortense Zones, at the boundary Early Bajocian-Late Bajocian). The present paleontological study, joined to the already published data, allows to propose a biostratigraphical zonation of the Middle Jurassic Brachiopods suitable to the Southern Margin of the Western Tethys. This Brachiopod scale is correlated with the standard chronostratigraphy based on ammonites. It involves eight Zones, three of which are subdivided into two Subzones and five Interval Zones where Brachiopods are missing. Moreover, Brachiopods have been not discovered in Early Aalenian and in Late Callovian. The appurtenance of different Brachiopod communities to the north-western European and to the Northern and Southern Tethyan paleobiogeographical realms is investigated. At last, the two Brachiopod zonations established on the Northern and Southern Margins of the Western Tethys are compared.