Bryozoan Phylogenetic Position and Dates of Its Early Divergences
- 责任者：Hao Jiasheng (College of Life Sciences ; Anhui Normal University ; Wuhu 241000 ; China) ; Sun Xiaoyan
- 刊名：Acta Micropalaeontologica Sinica
- 出版年：2010
- 卷期：27(1)
- 关键词：苔藓动物门 ; Bryozoa
- 页码：p.1-12
- 图表：2 illus., 4 tables, 71 refs.
- 分类号：1103
- issnNo：ISSN1000-0674
- isbnNo：CN32-1189/Q
Bryozoa is one of the key groups in the metazoan evolutionary studies because of their unique morphological and embryological traits. By analyzing the SSU and LSU rRNA sequences of 38 lophotrochozoan species with diploblastic animals as the outgroup using maximum-parsimony, maximum-likelihood and Bayesian-inference methods, the result suggests that the "Lophophorata" (including Bryozoa, Brachiopoda and Phoronida) is not a monophyletic entity and bryozoans form a monophyletic group, occupying the basal position of the tree including nearly all lophotrochozoan animal phyla. Phylochronological analyses show that the bryozoans diverged from other lophotrochozoans about 634 Ma, the phylactolaemate bryozoans diverged from the gymnolaemate bryozoans about 607 Ma during the Ediacaran Period of the Neoproterozoic Era, in spite the fact that the earliest bryozoans have been only found in the Tremadocian strata of the Ordovician.