 The spiders are unique in the flexible and teethed hook-like claws on the last segments (tarsus) of their legs. These elongated claws resemble those of spiders in the family Gradungulidae of Australia and New Zealand, but the two families are only distantly related. Hooked tarsal claws are also present to a lesser extent in the unrelated genera Doryonychus of Tetragnathidae, Hetrogriffus of Thomisidae and Celaenia of Araneidae.
