Phylogenetic relationships of the suborders of Coleoptera (insecta)

One hundred seven external and internal characters of larval and adult repr esentatives of 28 genera of the coleopteran suborders were analyzed cladist ically. Four groups of Neuropterida were introduced as outgroup. The analys is yielded 18 trees with a minimum of 194 steps (CI 0.691). All trees suppo rt the monophyly of all four suborders and a branching pattern (Archostemat a + (Adephaga + (Myxophaga + Polyphaga))). The presence of elytra with meso - and metathoracic locking devices, the specific hind-wing folding, the clo se connection of ex-posed sclerites, the absence of the mera, the absence o f eight thoracic muscles, the reduced abdominal sternite I, and the invagin ation of terminal segments are autapomorphies of Coleoptera. The monophyly of Coleoptera excl. Archostemata is supported by further transformations of the thoracic sclerites such as absence of the mesothoracic discriminal lin e and katepisternal joint, by an internalized or absent metathoracic trocha ntin, by the presence of a bending zone in the hind-wing, and by eight furt her muscle losses. Fusion of tibia and tarsus and presence of a single claw are larval synapomorphies of Myxophaga and Polyphaga. Adults are character ized by fusion of protrochantin and propleura and by the rigid connection o f the meso- and metathoracic ventrites. The eucinetoid lineage of Polyphaga is characterized by the secondary absence of the bending zone of the alae. This results in a distinctly simplified wing folding mechanism. The monoph yly of Cucujiformia (+ Bostrichoidea) is supported by the presence of crypt onephric Malpighian tubules. Transformations of fore-and hind-wings, reinfo rcement and simplification of the thoracic exoskeleton, and an efficient us e of a distinctly reduced set of thoracic muscles play an important role in the early evolution of Coleoptera. Many different larval character transfo rmations take place in the earlier Mesozoic within the suborders. (C) 2000 The Willi Hennig Society.