Three-dimensionally preserved soft-tissues and calcareous hexactins in a Silurian sponge: implications for early sponge evolution
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Sponges (Porifera), as one of the earliest-branching animal phyla, are crucial for understanding early metazoan phylogeny. Recent studies of Lower Palaeozoic sponges have revealed a variety of character states and combinations unknown in extant taxa, challenging our views of early sponge morphology. The Herefordshire Konservat-Lagerstätte yields an abundant, diverse sponge fauna with three-dimensional preservation of spicules and soft tissue. Carduispongia pedicula gen. et sp. nov. possesses a single layer of hexactine spicules arranged in a regular orthogonal network. This spicule type and arrangement is characteristic of the reticulosans, which have traditionally been interpreted as early members of the extant siliceous class Hexactinellida. However, the unusual preservation of the spicules of C. pedicula reveals an originally calcareous composition, which would be diagnostic of the living class Calcarea. The soft tissue architecture closely resembles the complex sylleibid or leuconid structure seen in some modern calcareans and homoscleromorphs. This combination of features strongly supports a skeletal continuum between primitive calcareans and hexactinellid siliceans, indicating that the last common ancestor of Porifera was a spiculate, solitary, vasiform animal with a thin skeletal wall.
Date Issued
2019-07-31
Date Acceptance
2019-07-09
Citation
Royal Society Open Science, 2019, 6 (7), pp.1-13
ISSN
2054-5703
Publisher
Royal Society, The
Start Page
1
End Page
13
Journal / Book Title
Royal Society Open Science
Volume
6
Issue
7
Copyright Statement
© 2019 The Authors.
Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Identifier
https://royalsocietypublishing.org/doi/10.1098/rsos.190911
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
exceptional preservation
Herefordshire Lagerstatte
Porifera
Reticulosa
Silurian
PHYLOGENY
Herefordshire Lagerstätte
Porifera
Reticulosa
Silurian
exceptional preservation
Publication Status
Published
Date Publish Online
2019-07-31