1. Snodgrass, R. E. Evolution of the Annelida, Onychophora and Arthropoda. Smithson. Misc. Collect. 97, 1–159 (1938).
2. Wills, M. A., Briggs, D. E. G., Fortey, R. A., Wilkinson, M. & Sneath, P. H. A. Arthropod Fossils and Phylogeny (ed. Edgecombe, G. D.) 33–105 (Columbia Univ. Press, New York, 1998).
3. Wheeler, W. C., Cartwright, P. & Hayashi, C. Y. Arthropod phylogeny: A combined approach. Cladistics 9, 1–39 (1993).
4. Regier, J. C. & Shultz, J. W. Molecular phylogeny of arthropods and the significance of the Cambrian “explosion” for molecular systematics. Am. Zool. 38, 918–928 (1998).
5. Wheeler, W. C. Arthropod Fossils and Phylogeny (ed. Edgecombe, G. D.) 9–32 (Columbia Univ. Press, New York, 1998).