Collembola ( Schaller 1970 )

R. G. Beutel & S. N. Gorb, 2001, Ultrastructure of attachment specializations of hexapods (Arthropoda): evolutionary patterns inferred from a revised ordinal phylogeny, J. Zool. Syst. Evol. Research 39, pp. 177-207 : 179

2 Collembola ( Schaller 1970)

The pretarsus is a very short but separate leg section. On the ventral side, opposed to the single claw a spur­like empodial appendage and an empodial tubercle are present, and in some springtails an accessory empodial appendage. The claw is triangular in cross­section with a median edge – sometimes toothed – and two lateral edges. The lateral edges are equipped with one lateral tooth in most species. Sminthurids (e.g. Sphyrotheca sp.) are characterized by a membranous claw sheath (tunica; Schaller 1970).