Mississippian chondrichthyans from the area of Krzeszowice, southern Poland

Abstract

Two new assemblages of Mississippian pelagic chondrichthyan microremains were recovered from the pelagic limestone of the area of Krzeszowice, NW of Kraków, Poland. The older assemblage represents the upper Tournaisian of Czatkowice Quarry and the younger one the upper Viséan of the Czernka stream valley at Czerna. The teeth of symmoriiform Falcatidae are the major component of both collections. A comparison of the taxonomic composition of the assemblage from Czerna (with the falcatids and Thrinacodus as the major components) to the previously published materials from the Holy Cross Mountains (Poland), Muhua (southern China), and Grand Canyon (Northern Arizona, USA) revealed the closest similarity to the first of these, probably deposited in a deeper water environment, relatively far from submarine carbonate platforms. A short review of Mississippian falcatids shows that the late Viséan-Serpukhovian period was the time of the greatest diversity of this group.

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

“…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; Rees and Underwood, 2006, 2008; Klug et al, 2010; Leuzinger et al, 2015, 2017; Stumpf 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).…”

“…The crown of Parvodus is similar to some extent to that of some Devonian euselachian sharks such as protacrodontids from the upper Famennian or Utah, Nevada and Middle Tournaisian of Muhua, China. However, protacrodont teeth are characterized by a wider base, which is significantly extended lingually with larger nutritive foramina (Ginter, 2001; Ginter and Sun, 2007).…”

“…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; Rees and Underwood, 2006, 2008; Klug et al, 2010; Leuzinger et al, 2015, 2017; Stumpf and Kriwet, 2019; Stumpf et al, 2021a).…”

Acta Geologica Polonica

“…In addition to a few hundred scales, one broken shark tooth was found. For several years the material remained unidentified, until the re-examination and the first precise description of the dentition of "Ctenacanthus" costellatus Traquair, 1884 from the Viséan of Scotland, UK (Ginter 2002; and the subsequent identification of comparable teeth in Derbyshire (England, UK) and the Holy Cross Mountains (Poland; Ginter et al 2015). Comparison of the scales and the tooth from the Włodawa IG-4 borehole to known specimens of "C." costellatus showed that the former most probably also represent this species.…”