Taxonomy and evolution of late Tournaisian and Viséan (early Carboniferous) Heterostrotioninae (Rugosa, Anthozoa) from SE China

Abstract

Colonial rugose corals with a heterocoral-like septal pattern are diverse and common in the Tournaisian–Viséan (Mississippian) of South China. Numerous species were named in classical works but most of them require systematic revision. Newly collected material allowed eight Heterostrotion species to be recognized (ranging from the upper Tournaisian up to the middle Viséan), including a new species H. huaqiaoense; three Stylostrotion species (middle Viséan), including a new species S. houi and four Polygonaria species (upper Tournaisian and upper Viséan). Heterostrotion as the oldest genus of the Stylostrotionidae probably originated in the western Palaeotethys and migrated to South China during the Tournaisian. The development of the cerioid genus Polygonaria from large-sized Heterostrotion during the late Tournaisian is described. The origin of Stylostrotion is however proposed in the evolution of Heterostrotion by a reduction of the minor septa and the development of a columella during the middle Viséan. Stylostrotion is known only from China, where it seems to have evolved by homeomorphy with Siphonodendron, which only occurred in that area in the late Viséan.

http://zoobank.org/urn:lsid:zoobank.org:pub:15F3D222-7027-4771-A8B5-05F024D298A0

Keywords:

• corals
• evolution
• homeomorphy
• Heterostrotion
• Stylostrotion
• Polygonaria

Acknowledgements

The authors thank Hongfei Hou (Beijing) and Xianghe Wu (Guiyang) for their long-lasting guidance and cooperation in the field. Luc Hance is thanked for his help identifying the foraminifers. Lin Wei and Le Yao (Nanjing) are thanked for their help with the Chinese literature and for searching for Yü’s holotype in the collection of the Nanjing Institute of Geology and Palaeontology. Błajez Berkowski (Poznan) and Sergio Rodríguez (Madrid) are thanked for their careful review of the manuscript.

Associate Editor: Ken Johnson