The flattened, explanate tibiae in nymphs is found in Coreidae. The form of the tibiae don't necessarily carry on to the adult form - usually at least the hind tibiae retains this, but can be lost completely (eg Mictis caja). Info. from Kumar (1966): Studies on the biology, immature stages, and relative growth of some australian bugs of the superfamily Coreoidea (Hemiptera : Heteroptera).