Data from: Ontogeny of the articulated yiliangellinine trilobite Zhangshania typica from the lower Cambrian (Series 2, Stage 3) of southern China

New discoveries of the early Cambrian yiliangellinine trilobite Zhangshania typica Li and Zhang in Kunming preserve almost all instars from early postembryonic (protaspid) to mature (holaspid) phases in articulated state, in addition to mature specimens with antennae bearing paired spines on the basal articles. The ontogenetic series shows protarthrous development with some, but likely not all, early holaspid instars expressing additional pygidial segments, gradual rearward migration of the location of the longest pleural spines on the trunk segments, and striking positive allometry of the genal spines. It also reveals Parazhangshania sichuanensis Li and Zhang, 1990 to be the holaspid stage 3 of Z. typica, and therefore its junior synonym. This new find in the Hongjingshao Formation provides species-based regional correlation across the South China block and Z. typica may provide an important biostratigraphic marker for the base of the traditional Tsanglangpuan Stage.昆明地区发现的早寒武世宜良虫亚科（Yiliangellinine）三叶虫典型张氏虫（Zhangshania typica Li & Zhang）新标本，保存了几乎全部从胚后发育早期（原甲期，protaspid）至成熟（全甲期，holaspid）的关节连接完好的发育龄期（instars）；此外还发现了基节上带有成对刺的触角的成熟标本。该个体发育序列（ontogenetic series）显示其具有原节式发育特征：部分（但并非全部）早期全甲期龄期个体可发育额外的尾甲体节（pygidial segments），躯干体节（trunk segments）上最长肋刺（pleural spines）的位置逐渐向后迁移，且颊刺（genal spines）呈现显著的正异速生长（positive allometry）模式。本研究还证实，1990年由李与张建立的四川副张氏虫（Parazhangshania sichuanensis Li & Zhang, 1990）实为典型张氏虫的全甲期第3龄期，因此该种为典型张氏虫的次同物异名（junior synonym）。本次在红井哨组（Hongjingshao Formation）中的新发现，可为华南地块（South China block）建立基于物种的区域地层对比框架；而典型张氏虫或可成为传统沧浪铺阶（Tsanglangpuan Stage）底界的重要生物地层标志（biostratigraphic marker）。