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Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion.

ABSTRACT: Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.

SUBMITTER: Shore AJ

PROVIDER: S-EPMC7775780 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion.

Shore A J AJ Wood R A RA Butler I B IB Zhuravlev A Yu AY McMahon S S Curtis A A Bowyer F T FT

Science advances 20210101 1

Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in <i>Namacalathus</i> from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer ...[more]

PMID: 33523867

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