The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores

Glyptosphaerites is a stemless, directly attached diploporite characterized by five ambulacra that have multiple facets and extend over the theca, but entirely lack flooring and cover plates. The food grooves lack any systematic relationship to the underlying thecal plates and grew out from a mouth...

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Autores principales:	Christopher R. C. Paul, Ursula Toom
Formato:	article
Lenguaje:	EN
Publicado:	Estonian Academy Publishers 2021
Materias:	blastozoa anambulacralia nov. ambulacralia nov. sphaeronitoida glyptosphaerites protocrinitoida. Geology QE1-996.5
Acceso en línea:	https://doaj.org/article/9bd143a7e0c34bd995975b3bf772cf98
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spelling	oai:doaj.org-article:9bd143a7e0c34bd995975b3bf772cf982021-11-16T14:59:56ZThe diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores1736-47281736-755710.3176/earth.2021.15https://doaj.org/article/9bd143a7e0c34bd995975b3bf772cf982021-11-01T00:00:00Zhttps://kirj.ee/wp-content/plugins/kirj/pub/earth-4-2021-224-239_20211116085401.pdfhttps://doaj.org/toc/1736-4728https://doaj.org/toc/1736-7557Glyptosphaerites is a stemless, directly attached diploporite characterized by five ambulacra that have multiple facets and extend over the theca, but entirely lack flooring and cover plates. The food grooves lack any systematic relationship to the underlying thecal plates and grew out from a mouth with a frame of six plates; five radial circumorals and a sixth interradial plate in the CD interambulacrum. The mouth was covered by a palate of eleven palatal plates. These characters are shared by most Sphaeronitidae, whereas traditionally Glyptosphaerites has been associated with diploporites that possess a stem and ambulacra with biserial flooring plates that alternate, left and right, and each of which supports a single brachiole facet. Such diploporites are characterized by Protocrinites, which has cover plates over its ambulacra and mouth but lacks a palate. Glyptosphaerites and Protocrinites are typical of two major divisions within the Diploporita, here called the Anambulacralia and Ambulacralia, respectively. The oldest identified anambulacralian is the middle Cambrian âeocrinoidâ Lichenoides. Diplopores of Glyptosphaerites leuchtenbergi arose on plate sutures as a single perpendicular canal like an epispire. This became incorporated into one plate as a second perpendicular canal developed on the suture. Further plate growth increased the separation of the two perpendicular canals until a standard distance was established when both canals became incorporated into the plate. Thus, the axes connecting perpendicular canals are perpendicular to plate sutures. In G. leuchtenbergi, diplopores were preferentially incorporated into one plate, often resulting in diplopores being concentrated in the adoral halves of thecal plates.Christopher R. C. PaulUrsula ToomEstonian Academy Publishersarticleblastozoaanambulacralia nov.ambulacralia nov.sphaeronitoidaglyptosphaeritesprotocrinitoida.GeologyQE1-996.5ENEstonian Journal of Earth Sciences, Vol 70, Iss 4, Pp 224-239 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	blastozoa anambulacralia nov. ambulacralia nov. sphaeronitoida glyptosphaerites protocrinitoida. Geology QE1-996.5
spellingShingle	blastozoa anambulacralia nov. ambulacralia nov. sphaeronitoida glyptosphaerites protocrinitoida. Geology QE1-996.5 Christopher R. C. Paul Ursula Toom The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
description	Glyptosphaerites is a stemless, directly attached diploporite characterized by five ambulacra that have multiple facets and extend over the theca, but entirely lack flooring and cover plates. The food grooves lack any systematic relationship to the underlying thecal plates and grew out from a mouth with a frame of six plates; five radial circumorals and a sixth interradial plate in the CD interambulacrum. The mouth was covered by a palate of eleven palatal plates. These characters are shared by most Sphaeronitidae, whereas traditionally Glyptosphaerites has been associated with diploporites that possess a stem and ambulacra with biserial flooring plates that alternate, left and right, and each of which supports a single brachiole facet. Such diploporites are characterized by Protocrinites, which has cover plates over its ambulacra and mouth but lacks a palate. Glyptosphaerites and Protocrinites are typical of two major divisions within the Diploporita, here called the Anambulacralia and Ambulacralia, respectively. The oldest identified anambulacralian is the middle Cambrian âeocrinoidâ Lichenoides. Diplopores of Glyptosphaerites leuchtenbergi arose on plate sutures as a single perpendicular canal like an epispire. This became incorporated into one plate as a second perpendicular canal developed on the suture. Further plate growth increased the separation of the two perpendicular canals until a standard distance was established when both canals became incorporated into the plate. Thus, the axes connecting perpendicular canals are perpendicular to plate sutures. In G. leuchtenbergi, diplopores were preferentially incorporated into one plate, often resulting in diplopores being concentrated in the adoral halves of thecal plates.
format	article
author	Christopher R. C. Paul Ursula Toom
author_facet	Christopher R. C. Paul Ursula Toom
author_sort	Christopher R. C. Paul
title	The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
title_short	The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
title_full	The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
title_fullStr	The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
title_full_unstemmed	The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores
title_sort	diploporite blastozoan glyptosphaerites (echinodermata: blastozoa) and the origin of diplopores
publisher	Estonian Academy Publishers
publishDate	2021
url	https://doaj.org/article/9bd143a7e0c34bd995975b3bf772cf98
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The diploporite blastozoan Glyptosphaerites (Echinodermata: Blastozoa) and the origin of diplopores

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