The sponge pump as a morphological character in the fossil record
Abstract The timing of early animal evolution remains one of the biggest conundrums in biology. Molecular data suggest Porifera diverged from the metazoan lineage some 800 Ma to 650 Ma, which contrasts with the earliest widely accepted fossils of sponges at 535 Ma. However, the lack of criteria by w...
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crcambridgeupr:10.1017/pab.2021.43 2024-09-15T18:20:13+00:00 The sponge pump as a morphological character in the fossil record Aragonés Suarez, Pablo Leys, Sally P. Natural Sciences and Engineering Research Council of Canada 2022 http://dx.doi.org/10.1017/pab.2021.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0094837321000439 en eng Cambridge University Press (CUP) https://creativecommons.org/licenses/by/4.0/ Paleobiology volume 48, issue 3, page 446-461 ISSN 0094-8373 1938-5331 journal-article 2022 crcambridgeupr https://doi.org/10.1017/pab.2021.43 2024-08-07T04:02:56Z Abstract The timing of early animal evolution remains one of the biggest conundrums in biology. Molecular data suggest Porifera diverged from the metazoan lineage some 800 Ma to 650 Ma, which contrasts with the earliest widely accepted fossils of sponges at 535 Ma. However, the lack of criteria by which to recognize the earliest animals in the fossil record presents a challenge. The sponge body plan is unchanged since the early Cambrian, which makes a sponge-type animal a good candidate for the earliest fossils. Here we propose a method for identifying an organism as sponge grade by translating the sponge pump character into a quantifiable morphological trait. We show that the ratio between the two major components of the aquiferous system, the cross-sectional area of the osculum (OSA) and the surface area of the whole sponge (SA), is an effective metric of the pump character of extant sponges and that the slope of this ratio is distinct for three classes of Porifera: Demospongiae, Calcarea, and Hexactinellida. Furthermore, this metric is effective at distinguishing as sponges both extant taxa and fossils from two extremes of the Phanerozoic, the Cambrian and Paleogene. We tested this metric on the putative Ediacaran sponge Thectardis avalonensis from Mistaken Point, Newfoundland, and found Thectardis fits both with Cambrian sponges and with modern demosponges. These analyses show that the OSA/SA ratio is a reliable character by which to identify fossils as sponge grade, opening up exciting possibilities for classifying new fossils as sponges. Article in Journal/Newspaper Newfoundland Cambridge University Press Paleobiology 1 16 |
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Cambridge University Press |
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crcambridgeupr |
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English |
description |
Abstract The timing of early animal evolution remains one of the biggest conundrums in biology. Molecular data suggest Porifera diverged from the metazoan lineage some 800 Ma to 650 Ma, which contrasts with the earliest widely accepted fossils of sponges at 535 Ma. However, the lack of criteria by which to recognize the earliest animals in the fossil record presents a challenge. The sponge body plan is unchanged since the early Cambrian, which makes a sponge-type animal a good candidate for the earliest fossils. Here we propose a method for identifying an organism as sponge grade by translating the sponge pump character into a quantifiable morphological trait. We show that the ratio between the two major components of the aquiferous system, the cross-sectional area of the osculum (OSA) and the surface area of the whole sponge (SA), is an effective metric of the pump character of extant sponges and that the slope of this ratio is distinct for three classes of Porifera: Demospongiae, Calcarea, and Hexactinellida. Furthermore, this metric is effective at distinguishing as sponges both extant taxa and fossils from two extremes of the Phanerozoic, the Cambrian and Paleogene. We tested this metric on the putative Ediacaran sponge Thectardis avalonensis from Mistaken Point, Newfoundland, and found Thectardis fits both with Cambrian sponges and with modern demosponges. These analyses show that the OSA/SA ratio is a reliable character by which to identify fossils as sponge grade, opening up exciting possibilities for classifying new fossils as sponges. |
author2 |
Natural Sciences and Engineering Research Council of Canada |
format |
Article in Journal/Newspaper |
author |
Aragonés Suarez, Pablo Leys, Sally P. |
spellingShingle |
Aragonés Suarez, Pablo Leys, Sally P. The sponge pump as a morphological character in the fossil record |
author_facet |
Aragonés Suarez, Pablo Leys, Sally P. |
author_sort |
Aragonés Suarez, Pablo |
title |
The sponge pump as a morphological character in the fossil record |
title_short |
The sponge pump as a morphological character in the fossil record |
title_full |
The sponge pump as a morphological character in the fossil record |
title_fullStr |
The sponge pump as a morphological character in the fossil record |
title_full_unstemmed |
The sponge pump as a morphological character in the fossil record |
title_sort |
sponge pump as a morphological character in the fossil record |
publisher |
Cambridge University Press (CUP) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1017/pab.2021.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0094837321000439 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Paleobiology volume 48, issue 3, page 446-461 ISSN 0094-8373 1938-5331 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/pab.2021.43 |
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Paleobiology |
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1 |
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16 |
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1810458590160355328 |