Impacts of climate-ocean-tectonic changes on early Paleozoic conodont ecology and evolution evidenced by the Canadian part of Laurentia

Taxonomy, biostratigraphy and biofacies of an Upper Ordovician (Katian) conodont fauna from the Casaio Formation, Northwest Spain

“…Conversely, it is far more frequent in the Late Ordovician warm-water environments of the British Isles, characterised by the Amorphognathus-Plectodina Biofacies, where it may comprise up to 10% of the faunal assemblage as in the Crûg Limestone (Lindström 1959, Orchard 1980, Savage & Bassett 1985. Icriodella and Panderodus are typical components of Late Ordovician-Llandovery shallowshelf biofacies (Aldridge & Jeppsson 1984, Sweet & Bergström 1984, Watkins & Kuglitsch 1997, Barnes 2019. The slightly older (Oandu Stage) Phragmodus undatus-Icriodella-Plectodina Biofacies of Baltoscandia is characterised by warm-water conodont taxa associated with bahamitic limestones (Sweet & Bergström 1984).…”

“…The slightly older (Oandu Stage) Phragmodus undatus-Icriodella-Plectodina Biofacies of Baltoscandia is characterised by warm-water conodont taxa associated with bahamitic limestones (Sweet & Bergström 1984). The ubiquitous general distribution of the coniform genera Panderodus and Drepanoistodus in the Vauréal Formation of Anticosti Island, Quebec, is prone to reflect its pelagic habit of life (Nowlan & Barnes 1981, Barnes 2019).…”

“…Sweet & Bergström 1984). For instance, the shallow shelf facies of the Midcontinent Realm in the Canadian Shield, characterised by Oulodus, Aphelognathus, Plectodina, Phragmodus and Rhipidognathus, records brief invasions of Amorphognathus, Icrio della and Periodon (North Atlantic Province spec ies), at times of maximum transgression of cooler Iapetus waters (Sweet et al 1971, Barnes & Fåhraeus 1975, Barnes 2019. However, Amorphognathus species in the Vauréal Formation follow an opposite pattern, with a much higher abundance in inner sublittoral than outer sublittoral environments (Zhang et al 2006).…”