Advances in Earth Science
• Articles •
QI Wen-tong. Advances on the Origin and Early Evolution of Modern Corals[J]. Advances in Earth Science, 2007, 22(10): 1094-1098.
Scleractinian corals were prominent reefbuilders in the Mesozoic and Cenozoic. Their sudden appearance with rich and varied fossils in the Anisian, Middle Triassic was impressive, after the endPermian mass extinction and a gap of 14 ma in the Early Triassic, when neither rugosan nor scleractinian coral fossils were found. This made the early phylogeny and systematics of the Scleractinian corals dubious and in debate. The object of this paper is to summarize the progress in probing the early phylogeny and systematics of the Order Scleractinia, as well as late discoveries of the Middle Triassic corals. The methods used are coral palaeontology and taxonomic studies of extant corals, i.e. comparison of skeletal structure, microstructure and soft body, search for early coral fossils, as well as molecular biology or molecular systematics. The most interesting results are: the hypothesis that the Scleractinian corals may have ascended from softbodied ancestors and that molecular data indicate two main phylogenetic lineages of scleractinians diverged about 300 Ma ago, in the Late Carboniferous, as well as new discoveries of the Anisian corals in China and in North America. With abundant fossil and extant representatives, and thus the necessity to synthesize three very different areas of scientific endeavor, there are many gaps and debates left in this field. The conclusion is that paleontologists and zoologists need to further coordinate their efforts to search for lost links and to bridge the gaps, in the study of the origin and early phylogeny of the Scleractinia.