What features distinguish the suborder Brachycera from other true flies?

The suborder Brachycera, often referred to as "short horns," is distinguished from the suborder Nematocera primarily by its antennal structure. While Nematocera possess whiplike antennae consisting of many similar segments, Brachycera have antennae that are contracted into a compound third segment. The remaining terminal flagellar segments in Brachycera appear as a pencil-like style or a bristle-like arista.1

Additionally, Brachycera are generally considered more highly specialized flies. Their palpi typically feature only one or two joints, and their antennae contain no more than six joints. These structural differences in the antennae serve as the primary diagnostic feature separating them from other dipterans.213