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Article: The biological affinity of Amsassia: new evidence from the Ordovician of North China

Publication: Palaeontology
Volume: 57
Part: 5
Publication Date: September 2014
Page(s): 1067 1089
Author(s): <p>Ning Sun, Robert J. Elias and Dong-Jin Lee</p>
Addition Information

How to Cite

SUN, N., ELIAS, R.J. and LEE, D.-J. 2014. The biological affinity of Amsassia: new evidence from the Ordovician of North China. Palaeontology57, 5, 1067–1089. doi: 10.1111/pala.12106

Author Information

  • Ning Sun - School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China (email:
  • Robert J. Elias - Department of Geological Sciences, The University of Manitoba, Winnipeg, Manitoba, Canada (email:
  • Dong-Jin Lee - Department of Earth and Environmental Sciences, Andong National University, Andong, Korea (email:
  • Dong-Jin Lee - College of Earth Sciences, Jilin University, Changchun, China

Publication History

  • Issue published online: 12 SEP 2014
  • Article first published online: 31 MAR 2014
  • Manuscript Accepted: 13 FEB 2014
  • Manuscript Received: 15 OCT 2013

Funded By

National Research Foundation of Korea
Korea Government. Grant Number: 2012-005612
Natural Sciences and Engineering Research Council of Canada

Online Version Hosted By

Wiley Online Library
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Amsassia shaanxiensis sp. nov. occurs in the Middle Ordovician part of the Jinghe Formation in Yongshou and the lower part of the Upper Ordovician Beiguoshan Formation in Longxian, Shaanxi Province, north-central China. In addition to module increase by bipartite longitudinal fission, which is also known in other species of Amsassia, tripartite and rare quadripartite fission are recognized in A. shaanxiensis. All species previously assigned to Lichenaria from the Middle to Upper Ordovician of Shaanxi probably belong to Amsassia. Therefore, Amsassia, rather than the tabulate coral Lichenaria, should be credited as an important contributor to reef-building in this area. Reports of Lichenaria from elsewhere in the North China Platform require confirmation in the light of the present study. Some morphological characteristics of Amsassia are comparable to those of tabulate corals, tetradiids and chaetetid sponges. Consequently, various authors have assigned Amsassia to the Lichenariida, Tetradiida (now Prismostylales; florideophycean rhodophyte algae) and Chaetetida. Other important characters, however, seem to exclude Amsassia from those taxonomic groups. The phacelocerioid organization of modules having separate walls would not be expected in sponges. The basic symmetry of individuals may have been radial, unlike the tetramerous symmetry of tetradiids. Module increase by longitudinal fission, involving infoldings of the wall, is fundamentally different from modes of increase in corals, tetradiids and chaetetids. The skeleton was probably aragonitic, whereas that of tabulates was calcitic. The affinity of Amsassia remains unresolved, but it is unlikely to have been a coral, tetradiid or sponge. Perhaps, like the tetradiids, Amsassia was an alga.

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