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Morphology of the radiodontan Lyrarapax from the early Cambrian Chengjiang biota

Published online by Cambridge University Press:  01 August 2016

Peiyun Cong
Affiliation:
Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, China 〈cong@ynu.edu.cn〉 〈xghou@ynu.edu.cn〉
Allison C. Daley
Affiliation:
Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford OX1 3PS, UK 〈allison.daley@zoo.ox.ac.uk〉 Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK
Gregory D. Edgecombe
Affiliation:
Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK 〈g.edgecombe@nhm.ac.uk〉
Xianguang Hou
Affiliation:
Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, China 〈cong@ynu.edu.cn〉 〈xghou@ynu.edu.cn〉
Ailin Chen
Affiliation:
Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming 650091, China 〈cong@ynu.edu.cn〉 〈xghou@ynu.edu.cn〉 Research Center of Paleobiology, Yuxi Normal University, Yuxi, Yunnan 653100, China 〈ailinchen@yxnu.net〉

Abstract

The recently described radiodontan Lyrarapax unguispinus Cong et al., 2014 from the Chengjiang biota (Cambrian Series 2, Stage 3) highlighted a new morphological type of frontal appendage and unique mouth structures, a functional combination reinforcing the diversification of feeding strategies of radiodontans during the early Cambrian. Here we describe Lyrarapax trilobus n. sp. from the same fossil Konservat-Lagerstätte. The new species differs from L. unguispinus in the morphology and distribution of endites on the frontal appendage and the strengthening structure of the body flaps. The two species resemble each other in body shape (pattern of flap size), neck segment number, cephalic plates, and most importantly a mouth characterized by concentric wrinkled furrows. The latter confirms that a soft mouth without sclerotized plates is a real feature of Lyrarapax and supports the idea that oral structures provide valid diagnostic characters within Radiodonta.

Type
Articles
Copyright
Copyright © 2016, The Paleontological Society 

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