Diminutive epibionts on crinoid stems from the Lower/Middle Devonian boundary in the Barrandian, Czech Republic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23420%2F22%3A43966762" target="_blank" >RIV/49777513:23420/22:43966762 - isvavai.cz</a>

Result on the web

<a href="http://hdl.handle.net/11025/51539" target="_blank" >http://hdl.handle.net/11025/51539</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Diminutive epibionts on crinoid stems from the Lower/Middle Devonian boundary in the Barrandian, Czech Republic

Original language description

Diminutive crinoid holdfasts and cemented tests of the foraminifers Psammosphaera and Toly pammina were observed on coarse bioclasts in weathered limestones of the Daleje-Třebotov Formation. Specimens were obtained in 1984 by washing so called “white beds” at a temporary locality in Praha Barrandov. A few millimeter sized bioclasts with epibionts were freed from hard limestone beds of the Třebotov Limestone near the Lower/Middle Devonian boundary by long-term weathering. Many of the crinoid holdfasts attached to pluricolumnals provoked a stereomic response of the host crinoid. Also the growth orientation of the crinoid epibiont is not random and indicates some crinoid-epibiont to crinoid host interaction. Reaction of host stereome and non-random stem orientation offer direct evidence of epi biont larval settlement and subsequent growth on the stem of a living crinoid host. The extensive growth of the host stereome ended by partial to total engulfing of the epibiont holdfast. This indicates advancing and finally successful defence of the host crinoid against the epibiont. The holdfast gives evidence that the small host crinoids offered a somewhat higher tier for even smaller epibiont crinoids. However, other observed holdfasts indicate fixation of larva and growth over loose bioclasts lying on a sea bed. Location of foraminifer test on bioclasts confims that foraminifers cemented and grew on loose echinodermal and brachiopod remains and preferred crevices and similar protected sites with concave profiles. This is clear evidence that diverse bioclasts (brachiopod shells, pelmatozoan ossicles) provided the hard substrate suitable for epibiont life on a sea bed.

Czech name

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Czech description

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Type

J_ost - Miscellaneous article in a specialist periodical

CEP classification

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OECD FORD branch

10506 - Paleontology

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Folia Musei rerum naturalium Bohemiae occidentalis - Geologica et Paleobiologica

ISSN

1805-2371

e-ISSN

1805-286X

Volume of the periodical

56

Issue of the periodical within the volume

1-2

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

16

Pages from-to

27-42

UT code for WoS article

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EID of the result in the Scopus database

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