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Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco

Complete, articulated crinoids from the Ordovician peri-Gondwanan margin are rare. Here, we describe a new species, Iocrinus africanus sp. nov., from the Darriwilian-age Taddrist Formation of Morocco. The anatomy of this species was studied using a combination of traditional palaeontological methods...

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Autores principales: Zamora, Samuel, Rahman, Imran A., Ausich, William I.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4675106/
https://www.ncbi.nlm.nih.gov/pubmed/26664800
http://dx.doi.org/10.7717/peerj.1450
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author Zamora, Samuel
Rahman, Imran A.
Ausich, William I.
author_facet Zamora, Samuel
Rahman, Imran A.
Ausich, William I.
author_sort Zamora, Samuel
collection PubMed
description Complete, articulated crinoids from the Ordovician peri-Gondwanan margin are rare. Here, we describe a new species, Iocrinus africanus sp. nov., from the Darriwilian-age Taddrist Formation of Morocco. The anatomy of this species was studied using a combination of traditional palaeontological methods and non-destructive X-ray micro-tomography (micro-CT). This revealed critical features of the column, distal arms, and aboral cup, which were hidden in the surrounding rock and would have been inaccessible without the application of micro-CT. Iocrinus africanus sp. nov. is characterized by the presence of seven to thirteen tertibrachials, three in-line bifurcations per ray, and an anal sac that is predominantly unplated or very lightly plated. Iocrinus is a common genus in North America (Laurentia) and has also been reported from the United Kingdom (Avalonia) and Oman (middle east Gondwana). Together with Merocrinus, it represents one of the few geographically widespread crinoids during the Ordovician and serves to demonstrate that faunal exchanges between Laurentia and Gondwana occurred at this time. This study highlights the advantages of using both conventional and cutting-edge techniques (such as micro-CT) to describe the morphology of new fossil specimens.
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spelling pubmed-46751062015-12-10 Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco Zamora, Samuel Rahman, Imran A. Ausich, William I. PeerJ Paleontology Complete, articulated crinoids from the Ordovician peri-Gondwanan margin are rare. Here, we describe a new species, Iocrinus africanus sp. nov., from the Darriwilian-age Taddrist Formation of Morocco. The anatomy of this species was studied using a combination of traditional palaeontological methods and non-destructive X-ray micro-tomography (micro-CT). This revealed critical features of the column, distal arms, and aboral cup, which were hidden in the surrounding rock and would have been inaccessible without the application of micro-CT. Iocrinus africanus sp. nov. is characterized by the presence of seven to thirteen tertibrachials, three in-line bifurcations per ray, and an anal sac that is predominantly unplated or very lightly plated. Iocrinus is a common genus in North America (Laurentia) and has also been reported from the United Kingdom (Avalonia) and Oman (middle east Gondwana). Together with Merocrinus, it represents one of the few geographically widespread crinoids during the Ordovician and serves to demonstrate that faunal exchanges between Laurentia and Gondwana occurred at this time. This study highlights the advantages of using both conventional and cutting-edge techniques (such as micro-CT) to describe the morphology of new fossil specimens. PeerJ Inc. 2015-12-07 /pmc/articles/PMC4675106/ /pubmed/26664800 http://dx.doi.org/10.7717/peerj.1450 Text en © 2015 Zamora et al. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Paleontology
Zamora, Samuel
Rahman, Imran A.
Ausich, William I.
Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title_full Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title_fullStr Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title_full_unstemmed Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title_short Palaeogeographic implications of a new iocrinid crinoid (Disparida) from the Ordovician (Darriwillian) of Morocco
title_sort palaeogeographic implications of a new iocrinid crinoid (disparida) from the ordovician (darriwillian) of morocco
topic Paleontology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4675106/
https://www.ncbi.nlm.nih.gov/pubmed/26664800
http://dx.doi.org/10.7717/peerj.1450
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