original descriptionStiller, F. 2001. Echinoid spines from the Anisian (Middle Triassic) of Qingyan, south-western China. Palaeontology 44, 529-551., available online athttps://doi.org/10.1111/1475-4983.00190 page(s): 541-546; text-figs. 7a-j, 8a-l [details]