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.
Houetal_Supplementary Data 1
Supposed protaspid and meraspides of Zhangshania typica from the Hongjingshao Formation, in Kunming, Yunnan Province, southern China: (1), supposed protaspid of this species, YKLP 12249; (2), same specimen of YKLP 12249 photographed under different lighting; (3), Meraspid degree 2, YKLP 12250; (4), enlargement of pygidium of specimen YKLP 12250; (5), Meraspid degree 3, YKLP 12251; (6), enlargement of pygidium of specimen YKLP 12251. p, pygidial segment; t, thoracic segment. Same abbreviations seen below. Scale bars are (1, 2, 4, 6) 200 µm; (3, 5) 500 µm.
HouetalSupplementaryData1_2col.tif
Houetal_Supplementary Data 2
Meraspides of Zhangshania typica from the Hongjingshao Formation, in Kunming, Yunnan Province, southern China: (1), Meraspid degree 4, YKLP 12252; (2), enlargement of cephalon of specimen YKLP 12252; (3), enlargement of pygidium of specimen YKLP 12252; (4), Meraspid degree 5, YKLP 12253;(5), Meraspid degree 6, YKLP 12254; (6), enlargement of pygidium of specimen YKLP 12254; (7), Meraspid degree 7, YKLP 12255; (8), enlargement of pygidium of specimen YKLP 12255; (9), Meraspid degree 8, YKLP 12256; (10), enlargement of pygidium of specimen YKLP 12256; (11), Meraspid degree 9, YKLP 12257; (12), enlargement of pygidium of specimen YKLP 12257. Scale bars are (3, 6, 8, 10, 12) 200 µm; (1–2, 4–5) 500 µm; (7, 9, 11) 1.0 mm.
HouetalSupplementaryData2_2col.tif
Houetal_Supplementary Data 3
Meraspides and early holaspides of Zhangshania typica from the Hongjingshao Formation, in Kunming, Yunnan Province, southern China: (1), Meraspid degree 10, YKLP 12319; (2), Meraspid degree 11, YKLP 12259; (3), Meraspid degree 12, YKLP 12260; (4), Meraspid degree 13, YKLP 12261; (5), enlargement of pygidium of specimen YKLP 12261; (6), Holaspid stage 1, YKLP 12262; (7), enlargement of pygidium of specimen YKLP 12262; (8), Holaspid stage 2, YKLP 12263; (9), enlargement of pygidium of specimen YKLP 12263. Scale bars are (5, 7, 9) 200 µm; (1–3) 500 µm; (4, 6, 8) 1.0 mm.
HouetalSupplementaryData3_2col.tif
