A silicified tommotiid from the lower Cambrian of Greenland

Three specimens of a new eccentrothecimorph tommotiid are described from the Paralelldal Formation of North Greenland. The specimens are all tubular structures composed of a number of individual sclerites. The sclerites were arranged in rings which fused to form a rigid tube during ontogeny. The tub...

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Bibliographic Details
Main Author: Skovsted, Christian
Format: Article in Journal/Newspaper
Language:English
Published: Enheten för paleobiologi 2016
Subjects:
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-1885
Description
Summary:Three specimens of a new eccentrothecimorph tommotiid are described from the Paralelldal Formation of North Greenland. The specimens are all tubular structures composed of a number of individual sclerites. The sclerites were arranged in rings which fused to form a rigid tube during ontogeny. The tube has a basal aperture presumably allowing attachment to a hard substrate. In morphology, both individual sclerites and the tubular scleritome are remarkably similar to specimens of Eccentrotheca from South Australia. However, the Greenland specimens are silicified and may have been either weakly mineralized or calcareous in original composition. In this respect they differ from all previously known tommotiids, considerably expanding the ultrastructural disparity of the Tommotiida and allowing comparison to a new range of possible lophotrochozoan fossils.