Fig. 1 in Fossil ants (Hymenoptera: Formicidae): ancient diversity and the rise of modern lineages

Fig. 1: The mesosoma of a Cretaceous ant, Gerontoformica robustus (BARDEN& GRIMALDI, 2014) in lateral view. The metapleural gland opening, visible posteroventrally on the propodeum, has traditionally been a key feature for assigning fossils to Formicidae. Note also the presence of a distinct metanotal sclerite, with clear sutures on all margins – present in many workers of early ant lineages, contrasted with almost all extant species where this segment is lost or reduced to a groove. Redrawn from BARDEN& GRIMALDI(2014).