Traditional phylogenetic and taxonomic methods based on examining and comparing morphological characters have in the last few decades been supplemented or even replaced by molecular phylogenetic methods that utilize a great number of molecular markers - mitochondrial and nuclear genes and genomic regions. Molecular phylogeny has profoundly changed our perception of the taxonomic position of great number of hexapod taxa and posed some intriguing questions on the evolution of basal hexapod lineages, as well as hexapods in relation to other arthropod higher-level taxa (crustaceans, myriapods and chelicerates). Regarding the question of relationships between entognathous hexapod taxa, some of the analyses yielded monophyletic Ellipura, while the others suggest the non-monophyly of Entognatha. Recent investigations of both molecular and morphological data support a closer relationship between hexapods and crustaceans, a so called "Pancrustacea" clade, opposing the classical "Tracheata" (myriapods + hexapods) hypothesis. Some of the results even suggest the reciprocal paraphyly of Crustacea and Hexapoda. Regarding the other two major arthropod clades, myriapods and chelicerates, some investigations support the sister group of Pancrustacea + Myriapoda (so called "Mandibulata"), while in some analyses support was found for the pairing of myriapods with chelicerates (so called " Paradoxopoda" or "Myriochelata"). These hypotheses would imply that water-to-land transition occurred at least three times during the evolution of the Arthropoda. All these new phylogenetic topologies still need to be properly evaluated and compared with classical hypotheses about the evolutionary relationships of hexapods and arthropods.Tradicionalne filogenetske i taksonomske metode temeljene na istraživanju i usporedbi morfoloških obilježja u novije se vrijeme dopunjavaju ili čak i potpuno zamjenjuju molekularno-filogenetskim metodama koje upotrebljavaju veliki broj molekularnih markera - mitohondrijalnih i nuklearnih gena i genomskih regija. Molekularna filogenija znatno je promijenila znanja o taksonomskom položaju velikoga broja taksona kukaca (Hexapoda) te otvorila brojna pitanja o evoluciji bazalnih linija Hexapoda i o njihovu odnosu prema ostalim glavnim linijama člankonožaca (Arthropoda) - rakova (Crustacea), stonoga (Myriapoda) i klještara (Chelicerata). Neke od analiza podržavaju monofiliju Ellipura, a neke upućuju na polifiliju ili parafiliju Entognatha. Brojna novija istraživanja molekularnih i morfoloških podataka podržavaju blisku vezu između Hexapoda i Crustacea, tzv. "Pancrustacea", koja je u suprotnosti s tradicionalnom hipotezom o bliskoj vezi između Hexapoda i Myriapoda (tzv. "Tracheata"). Neki od rezultata čak upućuju na uzajamnu parafiliju Crustacea i Hexapoda. Neke analize podržavaju vezu između Pancrustacea i Myriapoda (tzv. "Mandibulata"), a ostale daju podršku bliskoj vezi između Myriapoda i Chelicerata (tzv. "Paradoxopoda" ili "Myriochelata"). Te hipoteze upućuju na to da su tijekom evolucije člankonožaca barem tri puta neovisno pojedine linije prelazile iz vode na kopno. Sve ove nove pretpostavke moraju biti provjerene i uspoređene s klasičnim hipotezama o evolucijskim odnosima kukaca i člankonožaca
