This is Trilobite of the Order Agnostida belongs to the rare species Geragnostus boutouryensis.
Agnostid trilobite are usually rare in the Ordovician and only present the relative few species. The complete Order Agnostida will be vanished in the late Ordovician (Hirnantian) mass extinction event.
The species G. boutouryensis and G. occitanus was established by Howell,1935. Later was G. boutouryensis interpreted as synonym of G. occitanus by Dean,1966. According do Tortello, Vicaino und Álvaro, 2006* are both species are valid taxa. G. boutouryensis is especially characterizes by its subcylindrical outline of the glabella.
This is a wonderful specimen with a nice preservation from the lower Ordovician of Le Foulonin france.
(* Tortello, Vicaino und Álvaro, 2006 - EARLY ORDOVICIAN AGNOSTOID TRILOBITES FROM THE SOUTHERN
MONTAGNE NOIRE, FRANCE – J. Paleont., 80(3), 2006, pp. 477–495 )
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