Introduction to a New Hypothesis

The phylogenetic tree of arthropod lineages has been reconstituted by Giribet et al (2001),and in the tree hexapods (insects) are completely merged into the Crustacea to form a single group,Pancrustacea.This new hypothesis is entirely inconsistent with the conventional concepts on arthropod phylogeny,which attracts full attention to the entomologists and zoologists in the world.In this article I attempt to introduce the most important hypothesis on the phylogenetic relationships of the higher taxa of arthropods during the last century,and make a brief review for the progress,the present status and perspective in the research of arthropod phylogeny.