Ordovician cold water brachiopods from the Ougarta Mountain Range, Algerian Sahara.

In the Mid to Late Ordovician the area of the Ougarta Range in north-west Africa occupied a position in relative proximity to the South Pole. Eight successive low diversity brachiopod faunas, including the lingulide association dominated by unnamed species of Lingulobolus, the Darriwilian ?Sivorthis fraterna and Tissintia convergens, the Sandbian to early Katian Drabovinella regia and Tafilaltia destombesi-Rostricellula ambigena associations, the mid Katian Drabovinella maxima and Svobodaina cf. havliceki associations and the late Hirnantian Plectothyrella crassicostis chauveli Association are recognised. The brachiopod based correlation with the Middle to Upper Ordovician succession of the Anti-Atlas in Morocco, suggests the presence of some gaps in the Ougarta section. The occurrence of Svobodaina cf. havliceki in the Bou M'Haoud Formation Upper Member suggests its correlation with the upper part of the Lower Ktoua Formation of the Anti-Atlas. Among the other brachiopod taxa Drabovinella regia, Orbiculothyris cf. costellata, Tafilaltia destombesi, Rostricellula ambigena, together with the genera Fehamya, Mezotreta and Leptaena were previously unknown from Algerian Sahara. [ABSTRACT FROM AUTHOR]