SHU, D., CONWAY MORRIS, S., HAN, J., HOYAL CUTHILL, J.F., ZHANG, Z., CHENG, M., HUANG, H. 2017. Multi‐jawed chaetognaths from the Chengjiang Lagerstätte (Cambrian, Series 2, Stage 3) of Yunnan, China. Palaeontology, 60, 6, 763-772. DOI: 10.1111/pala.12325
Degan Shu, Simon Conway Morris, Jian Han, Jennifer F. Hoyal Cuthill, Zhifei Zhang, Meirong Cheng, and Hai Huang- Degan Shu - Early Life Institute & Department of Geology, & State Key Laboratory of Continental Dynamics Northwest University Xi'an China (Email: elidgshu@nwu.edu.cn)
- Simon Conway Morris - Department of Earth Sciences University of Cambridge Cambridge UK (Email: sc113@cam.ac.uk)
- Jian Han - Early Life Institute & Department of Geology, & State Key Laboratory of Continental Dynamics Northwest University Xi'an China
- Jennifer F. Hoyal Cuthill - Department of Earth Sciences University of Cambridge Cambridge UK (Email: jfh41@cam.ac.uk)
- Jennifer F. Hoyal Cuthill - Earth‐Life Science Institute Tokyo Institute of Technology Tokyo Japan
- Zhifei Zhang - Early Life Institute & Department of Geology, & State Key Laboratory of Continental Dynamics Northwest University Xi'an China
- Meirong Cheng - Early Life Institute & Department of Geology, & State Key Laboratory of Continental Dynamics Northwest University Xi'an China
- Hai Huang - College of Petroleum Engineering Xi'an Shiyou University Xi'an China
- Issue published online: 06 October 2017
- Manuscript Accepted: 03 August 2017
- Manuscript Received: 20 April 2017
Chaetognaths (arrow‐worms) are enigmatic in terms of their phylogenetic position, while the existence of Protosagitta spinosa from the Chengjiang Lagerstätte suggests minimal change in their unique bodyplan since at least the early Cambrian. Apart from rare (and sometimes controversial) soft‐bodied remains, the fossil record of chaetognaths is otherwise almost entirely dependent on early Palaeozoic phosphatic microfossils, some of which are placed amongst so‐called protoconodonts. Fused spine clusters are strikingly similar to the cephalic grasping apparatus of extant forms and are assumed to have had a comparable configuration. Here we report a new chaetognath, Ankalodous sericus gen. et sp. nov., coeval with Protosagitta but with a complex feeding apparatus consisting of multiple bundles of recurved spines whose principal function appears to have been grasping. Like all other chaetognaths a predatory mode of life is likely, but its position relative to the sediment–water interface is less certain. Reduction of the feeding apparatus, from the multi‐jawed arrangement of A. sericus to the grasping spines and associated smaller teeth seen in other chaetognaths, was probably a subsequent development and conceivably was linked with a shift to a pelagic mode of life. We also report a new specimen of Protosagitta. This confirms earlier observations but it possesses hitherto unrecognized features, including a cephalic tentacle and fin rays.
Data for this study are available in the Dryad Digital Repository http://zoobank.org/References/A79AEAF2-7D2B-4202-9399-42C7FDB36591 Wiley Online Library (Free Access)