Hydroscaphidae Lepiceridae Sphaeriusidae Torridincolidae †Triamyxidae Myxophaga is the second-smallest suborder of the Coleoptera after Archostemata, consisting of roughly 65 species of small to minute beetles in four families.
Myxophaga have several diagnostic features: the antennae are more or less distinctly clubbed with usually fewer than nine segments, mesocoxal cavities are open laterally and bordered by a mesepimeron and metanepisternum, the hind wings are rolled apically in the resting positions.
[10] The fossil record of myxophagan beetles is sparse, likely due to their small size limiting preservation potential.
[5] A fossil impression assigned to the living genus Hydroscapha in Hydroscaphidae is known from the Yixian Formation in the Jehol Biota, dating from the Early Cretaceous (Aptian).
[11] Fossils from the early Late Cretaceous (Cenomanian) aged Burmese amber from Myanmar, have been assigned to the extant genus Lepicerus and extinct genus Lepiceratus within Lepiceridae,[12][13][14] as well as the extant Sphaerius and Bezesporum and the extinct Burmasporum and Crowsonaerius, belonging to Sphaerusidae.