Data from: The oldest known bryozoan: Prophyllodictya (Cryptostomata) from the lower Tremadocian (Lower Ordovician) of Liujiachang, southwestern Hubei, central China

A new cryptostome bryozoan, Prophyllodictya simplex sp. nov., is described from the Nantzinkuan Formation (Lower Ordovician, lower Tremadoc) of Liujiachang, central China. This antedates the previously oldest known bryozoan by several million years. Colony morphology and the phylogenetic position of Prophyllodictya within Cryptostomata are explored. Phylogenetic analysis suggests that Cryptostomata (except Prophyllodictya) can be divided into two major groups, and that Prophyllodictya occupies a basal position in the cryptostome tree, which accords with its simple morphology and antiquity. A close relationship is evident between bryozoans from the South China palaeoplate and those from Baltica.本文记述了采自中国中部刘家场地区奥陶系下统特马豆克阶早期南津关组的1个新隐口目苔藓虫（cryptostome bryozoan）物种——简原叶网苔藓虫（Prophyllodictya simplex sp. nov.），该新种的发现将已知最古老苔藓虫的出现时间向前推进了数百万年，本文探讨了原叶网苔藓虫（Prophyllodictya）在隐口目（Cryptostomata）中的群体形态与系统发育位置，系统发育分析结果显示，隐口目（Cryptostomata，除原叶网苔藓虫外）可划分为两个主要类群，且原叶网苔藓虫位于隐口目系统发育树的基部位置，这与其简单的形态结构及古老的地质时代背景相吻合，研究同时表明，华南古板块（South China palaeoplate）的苔藓虫与波罗的古大陆（Baltica）的苔藓虫之间存在密切的亲缘联系。