Paleozoic echinoderm hangovers: Waking up in the Triassic
Ben Thuy1, Hans Hagdorn2 and Andy S. Gale3
- Author Affiliations
1Natural History Museum Luxembourg, Department of Palaeontology, 24 rue Münster, Luxembourg 2160, Luxembourg
2Muschelkalkmuseum Ingelfingen, Schlossstrasse 11, 74653 Ingelfingen, Germany
3School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, Great Britain
Abstract
Echinoderms are among the marine invertebrates that underwent the most severe losses at the end-Permian extinction. The prevailing paradigm claims an extreme bottleneck with only very few, if not single, holdovers ("hangovers" herein) sparking the post-Paleozoic radiation. Here we identify previously overlooked Triassic echinoids, ophiuroids, and asteroids as unambiguous members of Paleozoic stem groups. These echinoderm hangovers occurred almost worldwide and had spread into a wide range of paleoenvironments by the Late Triassic. Our discovery challenges fundamentals of echinoderm evolution with respect to end-Permian survival and sheds new light on the early evolution of the modern clades, in particular on Triassic ghost lineages (i.e., inferred but undocumented fossil record) of the crown-group look-alikes of the Paleozoic hangovers.
Received 21 December 2016. Revision received 3 February 2017. Accepted 11 February 2017.
©The Authors
Gold Open Access: This paper is published under the terms of the CC-BY license.
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