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

New discoveries of the early Cambrian yiliangellinid trilobite Zhangshania typica Li and Zhang, 1990 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 et 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.昆明地区早寒武世宜良虫科（Yiliangellinidae）三叶虫典型张氏虫（Zhangshania typica Li & Zhang, 1990）的新发现标本，保存了从胚胎发育后早期（原甲期，protaspid）至成熟（全甲期，holaspid）几乎所有龄期的铰接完整个体，同时还发现了触角基节具成对刺突的成熟标本。该个体发育序列呈现原节发育模式：部分（但并非全部）早期全甲龄期个体可发育额外的尾节体节，躯干体节上最长肋刺的位置逐渐向后迁移，且颊刺展现出显著的正异速生长特征。研究同时揭示，四川副张氏虫（Parazhangshania sichuanensis Li & Zhang, 1990）实为典型张氏虫的全甲3龄期，因此二者为晚出同物异名。此次在红井哨组（Hongjingshao Formation）的新发现，可为华南地块提供基于物种的区域地层对比依据；而典型张氏虫也可作为传统沧浪铺阶（Tsanglangpuan Stage）底界的重要生物地层标志。