A classic Late Frasnian chondrichthyan assemblage from southern Belgium

Abstract

ABSTRACT:Ginter, M., Gouwy, S. and Goolaerts, S. 2017. A classic Late Frasnian chondrichthyan assemblage from southern Belgium. Acta Geologica Polonica, 67 (3), 381-392. Warszawa.Samples from the Upper Frasnian (Devonian) of Lompret Quarry and Nismes railway section in Dinant Synclinorium, southern Belgium, yielded several chondrichthyan teeth and scales. The teeth belong to three genera: Phoebodus, Cladodoides and Protacrodus. The comparison with selected Late Frasnian chondrichthyan assemblages from the seas between Laurussia and Gondwana revealed substantial local differences of taxonomic composition due to palaeoenvironmental conditions, such as depth, distance to submarine platforms, oxygenation of water, and possibly also temperature. The assemblage from Belgium, with its high frequency of phoebodonts, is the most similar to that from the Ryauzyak section, South Urals, Russia, and the Horse Spring section, Canning Basin, Australia.

Devonian and Carboniferous dendroid graptolites from Belgium and their significance for the taxonomy of the Dendroidea

“…the ongoing excavation of light grey Lion Mb. limestones, for which a multidisciplinary study of the quarried sediments is ongoing (Goolaerts and Gouwy, 2015;Gouwy and Goolaerts, 2015;Ginter et al, 2017;Goolaerts et al, 2018).…”

Hybodontiform shark remains (Chondrichthyes, Elasmobranchii) from the Lower Triassic of Yunnan Province, China, with comments on hybodontiform diversity across the PTB

“…The most basal and oldest hybodontiform sharks known from complete, unambiguous skeletal remains are Tristychius and Onychoselache from the Viséan (early Carboniferous), part of the early Carboniferous chondrichthyan radiation (Friedman and Sallan, 2012). However, isolated teeth of general hybodontiform morphology (Ginter et al, 2002) date back further, to the Famennian (Late Devonian), indicating that hybodontiform sharks might have evolved and radiated prior to the end-Devonian mass extinction event (Duffin, 2001;Coates and Gess, 2007). Early Carboniferous holomorphic hybodontiform fossils occur in near-coastal and lagoonal to even freshwater deposits, indicating that hybodontiforms might have evolved in shallow-marine environments; it appears that they were euryhaline early in their evolutionary history, being able to tolerate different salinity regimes (e.g., Duffin, 1997;Duffin and Thies, 1997;Underwood, 2006, 2008;Klug et al, 2010;Leuzinger et al, 2015Leuzinger et al, , 2017Stumpf and Kriwet, 2019;Stumpf et al, 2021a).…”

“…Early Carboniferous holomorphic hybodontiform fossils occur in near-coastal and lagoonal to even freshwater deposits, indicating that hybodontiforms might have evolved in shallow-marine environments; it appears that they were euryhaline early in their evolutionary history, being able to tolerate different salinity regimes (e.g., Duffin, 1997;Duffin and Thies, 1997;Underwood, 2006, 2008;Klug et al, 2010;Leuzinger et al, 2015Leuzinger et al, , 2017Stumpf and Kriwet, 2019;Stumpf et al, 2021a). Devonian dental records assigned to hybodontiforms from marine settings also support this interpretation (Ginter et al, 2002). The Pennsylvanian (upper Carboniferous) hybodontiform Hamiltonichthys, represented by several holomorphic specimens and slightly more derived than Onychoselache, is known mostly from freshwater deposits (Maisey, 1989).…”