The morphological ontogeny of Lopheremaeus mirabilis (Csiszár 1962), the type species of Lopheremaeus Paschoal, 1988 (Plateremaeidae) is described and illustrated. The adult of this species has six pairs of notogastral setae (lp, h1, h2 and p-series), epimeral and anogenital hypertrichy, and 4–5 pairs of anal setae. The cuticle of juveniles is plicate, the larva lacks the gastronotal setae c3, la, lm and h3, the nymphs are multideficient (they lack also setae of d-series) and eupheredermous, i.e. they carry the exuvial scalps of previous instars on the gastronotum. In the adult, dorsal and ventral crests are present on all femora and trochanter III, and dorsal crest is present on trochanter IV, the nymphs have also dorsal and ventral crests on genua, whereas the larva has no crests. In all instars, seta d on all genua and tibiae is present, and all tarsi have basal bulb (containing muscles) and uniformly narrow distal stalk (with only tendons) at about mid-length. This species was reported only from Bulgaria, Bosnia-Herzegovina and North Macedonia, Romania and Georgia.