Abstract
The morphological disparity of lophotrochozoan phyla makes it difficult to predict the morphology of the last common ancestor. Only fossils of stem groups can help discover the morphological transitions that occurred along the roots of these phyla. Here, we describe a tubular fossil Yuganotheca elegans gen. et sp. nov. from the Cambrian (Stage 3) Chengjiang Lagerstätte (Yunnan, China) that exhibits an unusual combination of phoronid, brachiopod and tommotiid (Cambrian problematica) characters, notably a pair of agglutinated valves, enclosing a horseshoe-shaped lophophore, supported by a lower bipartite tubular attachment structure with a long pedicle with coelomic space. The terminal bulb of the pedicle provided anchorage in soft sediment. The discovery has important implications for the early evolution of lophotrochozoans, suggesting rooting of brachiopods into the sessile lophotrochozoans and the origination of their bivalved bauplan preceding the biomineralization of shell valves in crown brachiopods.
Original language | English |
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Article number | 4682 |
Pages (from-to) | 1-8 |
Number of pages | 7 |
Journal | Scientific Reports |
Volume | 4 |
DOIs | |
Publication status | Published - 15 May 2014 |
Bibliographical note
Copyright the Author(s). First published in Scientific reports, volume 4, article 4682. The original publication is available at http://doi.org/10.1038/srep04682. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.Erratum can be found at Scientific Reports volume 4 article 5502, https://doi.org/10.1038/srep05502
Keywords
- anatomy and histology
- animal
- China
- evolution
- fossil
- invertebrate
- phylogeny
- physiology, Animals
- Biological Evolution
- Fossils
- Invertebrates
- Phylogeny