Ganglbauer (1892) divides the whole order into two sub-orders only, the Caraboidea (the Adephaga of Sharp and the older writers) and the Cantharidoidea (including all other beetles), since the larvae of Caraboidea have five-segmented, two-clawed legs, while those of all other beetles have legs with four segments and a single claw.
Lameere (1900) has suggested three sub-orders, the Cantharidif ormia (including the Phytophaga, the Heteromera, the Rhynchophora and most of the Polymorpha of Sharp's classification), the Staphyliniformia (including the rove-beetles, carrion-beetles and a few allied' amilies of Sharp's Polymorpha), and the Carabidiformia (Adephaga).
Kolbe, on the other hand, insists that the weevils are the most modified of all beetles, being highly specialized as regards their adult structure, and developing from legless maggots exceedingly different from the adult; he regards the Adephaga, with their active armoured larvae with two foot-claws, as the most primitive group of beetles, and there can be little doubt that the likeness between larvae and adult may safely be accepted as a primitive character among insects.
The metasternum is without the transverse linear impression that is found in most families of Adephaga.
Two or three families may be regarded as aberrant Adephaga.