1. Adrain, J.M. 2011. Class trilobita. Zootaxa 3148: 104–109.
2. Apollonov, M.K., M.N. Chugaeva, and S.V. Dubinina. 1984. Trilobites and conodonts from the Batyrbay section (uppermost Cambrian–Lower Ordovician) in Maly Karatau Range (atlas of the palaeontological plates). Alma-Ata: Nauka. (in Russian).
3. Beresi, M.S. 2003. Cambrian sponge spicules and chancelloriid sclerites from the Argentine Precordillera: a review. Geologica Acta 1: 73–84.
4. Billings, E. 1860. On some new species of fossils from the limestone near Point Levis opposite Quebec. Proceedings of the Canadian Naturalist and Geologist 5: 301–324.
5. Billings, E. 1865. Paleozoic fossils, vol. 1. Montreal: Geological Survey of Canada.