Dysticidae. An analysis based on a morphological character matrix also came to this conclusion. However, two other studies with more genes have placed Amphizoidae as sister group to Aspidytidae.Balke, M., Ribera, I. & Beutel, R. G. 2005. The systematic position of Aspidytidae, the diversification of Dytiscoidea (Coleoptera, Adephaga) and the phylogenetic signal of third codon positions. Journal of Zoological Systematics and Evolutionary Research 43 (3): 223-242 With Aspidytidae and Amphizoa share the same morphology of the apical part of the pro-sternal process and the mesocoxal cavities. The phylogeny within Amphizoa has been analysed in two studies based on morphological characters and they suggested that A. davidis is an isolated species and sister to the remaining four species as follows (A davidis, (A. insolens, (A. striata, (A. sinica & A. lecontei)))).Edwards, J. G. 1951. Amphizoidae (Coleoptera) of the World. The Wasmann Journal of Biology vol. 8, no. 3 References External links Amphizoa insolens. California Beetles Project. Further reading Philips, K. T. and W. Xie. "Amphizoidae", in Arnett, R. H. and M. C. Thomas, American Beetles'' (CRC Press, 2001), vol. 1 Adephaga genera Palearctic insects Taxa named by John Lawrence LeConte