Shull, V.L., A.P. Vogler, M.D. Baker, D.R. Maddison, and P.M. Hammond 2001. Sequence Alignment of 18S Ribosomal RNA and the basal relationships of adephagan beetles: evidence for monophyly of the aquatic families and the placement of Trachypachidae. Systematic Biology, 50(6): 945-969.
Figure 6 did not print well. A higher-quality black and white PDF version of it is available, as is a color PDF version. A lower resolution color version is: