Abstract Trilobite occurrences and biodiversity from Devonian sections of the Ardennes Massif are presented. Fluctuations in diversity reflect environmental changes event-stratigraphic turnovers throughout Devonian. Peak is attained during Eifelian (Middle Devonian) when carbonate system developed. Six trilobite associations have been delineated based on cluster analysis. Distribution these correlated with deposition environments age strata.

1. Introduction The systematics and ontogeny of the Otarioninae were subjected to comprehensive studies Adrain & Chatterton (1994, 1995, 1996) who underlined importance heterochrony evolution nominal Otarionini. tribe’s chief genera in sheer species numbers are Siluro-Devonian Cyphaspis Burmeister, 1843 Otarion Zenker, 1833 which regarded as sister taxa by (1994). These workers provided a differential diagnosis chiefly intended discriminate basal Silurian members these for it was stated,...

Abstract The ‘Mur des douaniers’ biota at the former French/Belgian border contains a rich and diversified Lower Eifelian benthic fauna, especially trilobites. Palaeobiodiversity sedimentological analyses have led to interpretation of general palaeoenvironmental/palaeoecological context. This trilobite-rich locality is an exceptionally well-preserved Early fossil site with regard regional scale. Unfortunately, its growing reputation pillage now this palaeontological protected as Nature...

1. Introduction The Frasnian was a period of recurrent global eustatic perturbations that had already commenced in the Middle Devonian and led to major faunal crises. trilobites, encompassing exclusively benthic endobenthic inhabitants continental shelf, suffered consecutive blows from worldwide “drowning” reef ecosystems decline shallow water environments which they were confined (Feist, 1991, 1995). latest Kellwasser Event, though not by itself responsible for demise “coup de grâce” many...

Well-preserved specimens of the phacopine trilobites Morocops Basse (= Barrandeops McKellar & Chatterton) and Adrisiops gen.nov.are recorded from upper Emsian strata in Morocco.Morocops is a problematic taxon; close similarities its stratigraphically youngest members to earliest Geesops Struve are indicative grade taxonomy.So far, exclusively Gondwanan although potential congeners have been described peri-Gondwana.One oldest species occurs lower Eifelian French Ardennes (Laurussia).Its...

Species of the odontopleurine trilobites Leonaspis Richter & Richter, 1917 and Kettneraspis Prantl Přibyl, 1949 from Silurian Devonian have been studied. Dorsal tubercle spine patterns are highly variable deemed restricted use. The pygidial segmentation is consistent among species in development a rudimentary inner pleural ridge or wide space between axis. In Kettneraspis, an never developed but primitive condition to here. formation this auxiliary interior border pair was arrested...

Well-preserved trilobite specimens are recorded from Eifelian strata between the villages of Nismes (southern Belgium) and Vireux-Molhain (northern France). In area study lower Vieux Moulin Member Jemelle Formation crops out. The diversified associations this unit occur in dark shales siltstones during a deepening phase replace comparatively poorly fauna underlying Eau Noire Formation. This overturn local might, part, be considered regional expression globally recognised Choteč Event. A...