Fig. 26

Appendage specialization and differentiation among chelicerate clades. a Pycnogonids (sea spiders). b Horseshoe crabs. c Chasmataspidids. d Spiders. e Scorpions. f Whip scorpions (vinegaroons). g Stylonurine eurypterids. h Eurypterine eurypterids. Somites are labeled 0–VI; ‘m’ indicates the position of the mouth. Appendages are color coded by morphology and function: green = locomotory, red = modified for reproduction, blue = tactile/sensory function, yellow = raptorial, purple = modified for a swimming/digging. For Megalograptidae, darker shades of yellow and green indicate limbs with a raptorial and locomotory function respectively but with a different morphology to other limbs in the taxon with a similar function. Where sexual dimorphism is present the condition in the female is shown on the left and the male on the right