Phylogeny of the corbiculate bees (Apinae) as well as representative fossils from a variety of Tertiary deposits based on analysis of 51 adult morphological characters of external and internal skeletal features. Topology presented is a strict consensus of two most parsimonious trees: tree length, 65; consistency index, 81; and retention index, 93 (16). From top to bottom (and left to right), the fossils are Euglossa moronei Engel, Genus A, Genus B, Genus D, Apis henshawi Cockerell, Genus E, Genus G, Genus I, and Nogueirapis silacea (Wille). Eocene fossil taxa on the cladogram include genera A–I and the meliponine Kelneriapis. Black lines indicate noneusocial (solitary or communal) species; yellow indicates primitively eusocial lineages (i.e., lacking a morphologically specialized worker caste); red indicates advanced eusocial lineages. Fossils represented by individuals that are morphologically workers are indicated in green. Most fossil genera are not monotypic (e.g., Genus B has five species, Genus C has four species) (16).