Tabulate Corals after the Frasnian/Famennian Crisis: A Unique Fauna from the Holy Cross Mountains, Poland.

Mikołaj K Zapalski,Tomasz Wrzołek,Błażej Berkowski,Xijun Ni

doi:10.1371/journal.pone.0149767

Mikołaj K Zapalski, Tomasz Wrzołek + Show 2 more

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https://doi.org/10.1371/journal.pone.0149767

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Abstract

Famennian tabulate corals were very rare worldwide, and their biodiversity was relatively low. Here we report a unique tabulate fauna from the mid- and late Famennian of the western part of the Holy Cross Mountains (Kowala and Ostrówka), Poland. We describe eight species (four of them new, namely ?Michelinia vinni sp. nov., Thamnoptychia mistiaeni sp. nov., Syringopora kowalensis sp. nov. and Syringopora hilarowiczi sp. nov.); the whole fauna consists of ten species (two others described in previous papers). These corals form two assemblages—the lower, mid-Famennian with Thamnoptychia and the upper, late Famennian with representatives of genera ?Michelinia, Favosites, Syringopora and ?Yavorskia. The Famennian tabulates from Kowala represent the richest Famennian assemblage appearing after the F/F crisis (these faunas appear some 10 Ma after the extinction event). Corals described here most probably inhabited deeper water settings, near the limit between euphotic and disphotic zones or slightly above. At generic level, these faunas show similarities to other Devonian and Carboniferous faunas, which might suggest their ancestry to at least several Carboniferous lineages. Tabulate faunas described here represent new recruits (the basin of the Holy Cross mountains was not a refuge during the F/F crisis) and have no direct evolutionary linkage to Frasnian faunas from Kowala. The colonization of the seafloor took place in two separate steps: first was monospecific assemblage of Thamnoptychia, and later came the diversified Favosites-Syringopora-Michelinia fauna.

Highlights

Middle and Late Devonian (Frasnian) reefal structures were distributed on a global scale
The aim of this paper is to report further discoveries of upper Famennian tabulate corals from the Holy Cross Mountains in Central Poland, based on large collections of tabulates and rugosans acquired over the years by the University of Silesia
The Famennian tabulate fauna from Kowala consists of 10 species and represents the richest Famennian collection described so far from the Famennian, after the F/F crisis

Summary

Introduction

Middle and Late Devonian (Frasnian) reefal structures were distributed on a global scale. Most of them were dominated by microbialites, calcified cyanobacteria, stromatoporoids and tabulate corals [1, 2]. Tabulates represent a group which was markedly diversified during this time. The number of species was relatively high, and in many areas exceed 50 (Holy Cross Mountains: [3], Kuznetsk Basin: [4], Russian Platform and W slopes of Ural Mts.: [5]) or even 80 (Ardennes: [6, 7]) for Givetian and Frasnian counted together.

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