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Science 28 February 2003:
Vol. 299. no. 5611, pp. 1380 - 1384
DOI: 10.1126/science.1079846

Reports

A New Species of Yunnanozoan with Implications for Deuterostome Evolution

Degan Shu,1* Simon Conway Morris,2 Z. F. Zhang,1 J. N. Liu,1 Jian Han,1 Ling Chen,1 X. L. Zhang,1 K. Yasui,3 Yong Li4

Yunnanozoans are a distinctive clade of Lower Cambrian metazoans. Although widely accepted as deuterostomes, their exact placement within this superphylum is controversial. Here we describe a new species of Haikouella (H. jianshanensis) from the Chengjiang Lagerstätte (Yunnan, China) with exceptional preservation of a number of features. These include external gills, which suggest that the origin of the pharyngeal clefts was independent of the gills. The diagnostic branchial arches of chordates may, therefore, be composite structures. No evidence was found for the chordate-like structures that have been described in other yunnanozoans. We propose that yunnanozoans are stem-group deuterostomes, allied to the vetulicolians.

1 Early Life Institute and Department of Geology, Northwest University, Xi'an 710069, China, and School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
2 Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK.
3 Institute of Molecular Embryology and Genetics, Division of Development and Biohistory, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
4 College of Earth Science and Land Resources, Chang'an University, Xi'an 710054, China.
*   To whom correspondence should be addressed. E-mail: elidgshu{at}nwu.edu.cn and dgshu{at}sein.sxgb.com.cn


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THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
The earliest history of the deuterostomes: the importance of the Chengjiang Fossil-Lagerstatte.
D.-G. Shu, S. Conway Morris, Z.-F. Zhang, and J. Han (2009)
Proc R Soc B
   Abstract »    Full Text »    PDF »
The midline, oral ectoderm, and the arch-0 problem.
C. B. Kimmel and J. K. Eberhart (2008)
Integr. Comp. Biol. 48, 668-680
   Abstract »    Full Text »    PDF »
The earliest fossil record of the animals and its significance.
G. E Budd (2008)
Phil Trans R Soc B 363, 1425-1434
   Abstract »    Full Text »    PDF »
Deciphering deuterostome phylogeny: molecular, morphological and palaeontological perspectives.
B. J Swalla and A. B Smith (2008)
Phil Trans R Soc B 363, 1557-1568
   Abstract »    Full Text »    PDF »
Darwin's dilemma: the realities of the Cambrian 'explosion'.
S. Conway Morris (2006)
Phil Trans R Soc B 361, 1069-1083
   Abstract »    Full Text »    PDF »
Comment on "A New Species of Yunnanozoan with Implications for Deuterostome Evolution".
J. Mallatt, J. Chen, and N. D. Holland (2003)
Science 300, 1372c
   Full Text »    PDF »
Response to Comment on "A New Species of Yunnanozoan with Implications for Deuterostome Evolution".
D. Shu and S. C. Morris (2003)
Science 300, 1372d
   Full Text »    PDF »



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Science. ISSN 0036-8075 (print), 1095-9203 (online)