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Reinterpretation of the lower Cambrian brachiopod Heliomedusa orienta Sun and Hou, 1987A as a discinid

Published online by Cambridge University Press:  14 July 2015

Jun-Yuan Chen
Affiliation:
Nanjing Institute of Geology & Palaeontology, Nanjing 210008, China
Di-Ying Huang
Affiliation:
Nanjing Institute of Geology & Palaeontology, Nanjing 210008, China
Shou-Hwa Chuang
Affiliation:
144 Pasir Ris Road, Republic of Singapore 519131

Abstract

The Lower Cambrian brachiopod Heliomedusa orienta Sun and Hou, 1987a, first identified as a jellyfish, was later described as a craniopsoid brachiopod. A new sample of 1,150 individuals of this brachiopod, measuring 3.1–22.0 mm long, from two new sites of the Lower Cambrian Yuanshan Formation was examined. the sample includes several with exceptional preservation of nonmineralized skeletons that reveal previously unknown features and fill a gap in our knowledge of the detailed anatomy of fossil discinids. It is here reinterpreted as a discinid brachiopod on the basis of its many distinctive, discinid anatomical features, such as a longitudinally oval pedicle foramen in the anterior region of the posterior sector of the ventral valve; inferred, short, but large pedicle descending ventrally from the ventral valve; inferred, paired rectus muscles in the large pedicle canal; elongate scars of paired anterior adductors; and a median septum connected to a U-shaped ridge on the ventral interior. the two growing zones of its exceptionally preserved, unique lophophore extend posteriorly instead of anteriorly as in all Recent inarticulate brachiopods. Its recognition as the first and earliest discinoidean extends its stratigraphic range from the Ordovician to the Lower Cambrian. This reassignment implies that the organophosphatic, pediculate lingulids and discinids evolved before the carbonate, nonpediculate craniopsids and craniids. Its occurrence at chronological proximity to the Cambrian explosion of small metazoans sheds light on the early morphological diversification and the adaptive radiation of the Lower Cambrian brachiopods into the available niches.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Blochmann, F. 1900. Untersuchungen ueber den Bau der Brachiopoden, Pt. 2, Die Anatomie von Discinisca lamellosa (Broderip) und Lingula anatina Bruguiere. Gustav Fischer, Jena, p. 69124.Google Scholar
Broderip, W. J. 1833. Descriptions of Some New Species of Cuvier's family of Brachiopoda. Proceedings of the Zoological Society, London, p. 124125.Google Scholar
Bruguiere, J. G. 1797. Tableau Encyclopedique et Methodique des Trois Regnes de la Nature, 2, Vers, Coquilles, Mollusques et Polypiers. Paris, pls. 190286.Google Scholar
Junyuan, Chen, and Erdtmann, B. D. 1991. Lower Cambrian fossil Lagerstätte from Chengjiang, Yunnan, China: Insights for reconstructing early metazoan life, p. 5776. In Simonetta, A. M. and Conway Morris, S. (eds.), The Early Evolution of the Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge.Google Scholar
Junyuan, Chen, Hou, X. G., and Erdtmann, B. D. 1989. New soft-bodied fossil fauna near the base of the Cambrian System at Chengjiang, eastern Yunnan, China, p. 265278. In Chinese Academy of Sciences, Developments in Geoscience. Science Press, Beijing.Google Scholar
Junyuan, Chen, Zhou, G. Q., Zhu, M. Y., and Yeh, K. Y. 1996. The Chengjiang Biota: A Unique Window of the Cambrian Explosion. National Museum of Natural History, Taichong, Taiwan, China, 222 p.Google Scholar
Chuang, S. H. 1977. Larval development in Discinisca (inarticulate brachiopod). American Zoologist, 17:3954.CrossRefGoogle Scholar
Conway Morris, S., and Robison, R. A. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. The University of Kansas Paleontological Contributions Paper, 122, 48 p.Google Scholar
d'Orbigny, A. 1847. Considerations zoologiques et geologiques sur les brachiopodes ou palliobranches. Comptes Rendus Hebdomadaires de Seances de l'Academie de Seances, Paris, 25:193195, 266–269.Google Scholar
Gray, J. E. 1840. Synopsis of the Contents of the British Museum (forty-second edition). London, 370 p.Google Scholar
Hall, J., and Clarke, J. M. 1890. Extract from Volume VIII, Paleontology of New York. C. Van Benthuysen, Albany, New York, p. 120.Google Scholar
Havlicek, V. 1994. Kosovian inarticulate brachiopods and their ancestors (Late Ordovician, Prague Basin). Vestnik Ceskeho geologickeho ustavu, 69:5967.Google Scholar
Holmer, L. E., and Popov, L. E. 2000. Lingulata, p. 30146. In Kaesler, R. L. (ed.), Treatise on Invertebrate Paleontology. Pt. H. Brachiopoda 2 (revised). Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Xianguang, Hou. 1987. Two new arthropods from Lower Cambrian, Chengjiang, eastern Yunnan. Acta Palaeontologica Sinica, 26:236256.Google Scholar
Xianguang, Hou, and Weiguo, Sun. 1988. Discovery of Chengjiang Fauna at Meishucun, Jinning, Yunnan. Acta Palaeontologica Sinica, 27:112.Google Scholar
Shi-cheng, Huo, Degan, Shu, Xi-guang, Zhang, Zhi-lin, Cui, and Hao-wen, Tong. 1983. Notes on Cambrian bradoriids from Shaanxi, Yunnan, Sichuan, Guizhou, Hubei and Guangdong. Journal of Northwest University, 13:5675.Google Scholar
Yugan, Jin, and Huayu, Wang. 1992. Revision of the Lower Cambrian brachiopod Heliomedusa Sun and Hou, 1987. Lethaia, 25:3549.CrossRefGoogle Scholar
Koneva, S. P. 1986. A new family of Cambrian inarticulate brachiopods. Paleontological Journal, 1986, no. 1:2835.Google Scholar
Kutorga, S. S. 1848. Ueber die Brachiopoden-Familie der Siphontretaceae. Russisch-Kaiserliche Mineralogische Gesellschaft zu St. Petersbourg, Verhandlungen, 1847:250286.Google Scholar
Lee, Yuwen. 1975. Cambrian ostracods and their new knowledge from Sichuan, Yunnan and Shaanxi. Stratigraphy and Palaeontology Papers, Beijing, 2:3772.Google Scholar
Popov, L. E. 1992. The Cambrian radiation of brachiopods, p. 399423. In Lipps, J. H. and Signor, P. W. (eds.), Origin and Early Evolution of the Metazoa. Plenum Press, New York.CrossRefGoogle Scholar
Popov, L. E., and Holmer, L. E. 2000. Craniopsida, p. 164168. In Kaesler, R. L. (ed.), Treatise on Invertebrate Paleontology. Pt. H. Brachiopoda 2 (revised). Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Popov, L. E., Bassett, M. G., and Holmer, L. E. 2000. Craniata, p. 158164. In Kaesler, R. L. (ed.), Treatise on Invertebrate Paleontology. Pt. H. Brachiopoda 2 (revised). Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Rong, Jiayu. 1974. Cambrian Brachiopods, p. 113114. In Nanjing Institute of Geology and Palaeontology, Academia Sinica, Handbook of Palaeontology and Stratigraphy of Southern China. Science Press, Beijing.Google Scholar
Rowell, A. J. 1982. The monophyletic origin of the Brachiopoda. Lethaia, 15:299307.CrossRefGoogle Scholar
Sun, Weiguo, and Xianguang, Hou. 1987a. Early Cambrian medusae from Chengjiang, Yunnan, China. Acta Palaeontologica Sinica, 26:257271.Google Scholar
Sun, Weiguo, and Xianguang, Hou. 1987b. Early Cambrian worms from Chengjiang, Yunnan, China. Acta Palaeontologica Sinica, 26:299305.Google Scholar
Vanuxem, L. 1842. Geology of New York, Pt. 3, Comprising the Survey of the Third Geological District. Natural History of New York. Carroll and Cook, Albany, New York, 306 p.Google Scholar
Walcott, C. D. 1919. Middle Cambrian algae. Cambrian Geology and Paleontology IV. Smithsonian Miscellaneous Collections, 67:217260.Google Scholar
Willard, B. 1928. The brachiopods of the Ottosee and Holston formations of Tennessee and Virginia. Bulletin of the Harvard Museum of Comparative Zoology, 68:255292.Google Scholar
Williams, A., and Holmer, L. E. 1992. Ornamentation and shell structure of acrotretoid brachiopods. Palaeontology, 35:657692.Google Scholar
Williams, A., Brunton, C. H. C., and MacKinnon, D. I. 1997. Morphology, p. 321422. In Kaesler, R. L. (ed.), Treatise on Invertebrate Paleontology. Pt. H. Brachiopoda 2 (revised). Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Xiguang, Zhang, Xianguang, Hou, and Emig, C. C. 2003. Evidence of lophophore diversity in Early Cambrian Brachiopoda. Proceedings of the Royal Society, London, series B (supplement), 270:S65S68.Google Scholar