evolution of the mouthparts of insects

Abstract

We contrasted the expression patterns of several developmentally important genes in insects with mandibulate or stylate-haustellate mouthparts in order to better comprehend both the development and evolution of insect mouthparts. We found no major breaks in the evolution of mouthparts, but six in epochs with numerous innovations and few extinctions, namely the Late Carboniferous, Middle and Late Triassic, 'Callovian-Oxfordian,' 'Early' Cretaceous, and 'Albian-Cenomanian'. The three Permian-Triassic, Triassic-Jurassic, and Cretaceous-Cenozoic crises had no discernible effect on mouthpart types.