Ultrastructure of attachment specializations of hexapods (Arthropoda): evolutionary patterns inferred from a revised ordinal phylogeny Author R. G. Beutel Author S. N. Gorb text J. Zool. Syst. Evol. Research 2001 39 177 207 journal article 10.1046/j.1439-0469.2001.00155.x 95b3d62f-8fcc-4088-873f-b33f4a63d3fc 2360323 21 Phthiraptera Tarsi are one­ or two­segmented. A claw pad, dissimilar from that of ephemeropterans, is present in some representatives of Phthiraptera (Amblycera, Ischnocera part.) ( Fig. 3i ). Euplantulae which allow attachment to smooth surfaces are also present in some mallophagan species.