Dr Martin Smith martin.smith@durham.ac.uk
Associate Professor
Hallucigenia’s head and the pharyngeal armature of early ecdysozoans
Smith, M.R.; Caron, J.-B.
Authors
J.-B. Caron
Abstract
The molecularly defined clade Ecdysozoa1 comprises the panarthropods (Euarthropoda, Onychophora and Tardigrada) and the cycloneuralian worms (Nematoda, Nematomorpha, Priapulida, Loricifera and Kinorhyncha). These disparate phyla are united by their means of moulting, but otherwise share few morphological characters—none of which has a meaningful fossilization potential. As such, the early evolutionary history of the group as a whole is largely uncharted. Here we redescribe the 508-million-year-old stem-group onychophoran Hallucigenia sparsa2, 3, 4, 5, 6 from the mid-Cambrian Burgess Shale. We document an elongate head with a pair of simple eyes, a terminal buccal chamber containing a radial array of sclerotized elements, and a differentiated foregut that is lined with acicular teeth. The radial elements and pharyngeal teeth resemble the sclerotized circumoral elements and pharyngeal teeth expressed in tardigrades7, 8, 9, stem-group euarthropods10, 11, 12 and cycloneuralian worms13. Phylogenetic results indicate that equivalent structures characterized the ancestral panarthropod and, seemingly, the ancestral ecdysozoan, demonstrating the deep homology of panarthropod and cycloneuralian mouthparts, and providing an anatomical synapomorphy for the ecdysozoan supergroup.
Citation
Smith, M., & Caron, J. (2015). Hallucigenia’s head and the pharyngeal armature of early ecdysozoans. Nature, 523(7558), 75-78. https://doi.org/10.1038/nature14573
Journal Article Type | Article |
---|---|
Acceptance Date | May 18, 2015 |
Online Publication Date | Jun 24, 2015 |
Publication Date | Jun 24, 2015 |
Deposit Date | Oct 6, 2015 |
Publicly Available Date | Mar 28, 2024 |
Journal | Nature |
Print ISSN | 0028-0836 |
Electronic ISSN | 1476-4687 |
Publisher | Nature Research |
Peer Reviewed | Peer Reviewed |
Volume | 523 |
Issue | 7558 |
Pages | 75-78 |
DOI | https://doi.org/10.1038/nature14573 |
Public URL | https://durham-repository.worktribe.com/output/1430240 |
Related Public URLs | https://www.repository.cam.ac.uk/handle/1810/248498 |
Files
Accepted Journal Article
(1.4 Mb)
PDF
You might also like
climenv: Download, extract and visualise climatic and elevation data
(2023)
Journal Article
Evolution: Assembling the Deuterostome body plan
(2023)
Journal Article
Protomelission is an early dasyclad alga and not a Cambrian bryozoan
(2023)
Journal Article
TreeSearch: Morphological Phylogenetic Analysis in R
(2023)
Journal Article
The Cambrian cirratuliform Iotuba denotes an early annelid radiation
(2023)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search