Data from: Sensory evidence for complex communication and advanced sociality in early ants

Advanced social behavior, or eusociality, has been evolutionarily
profound, allowing colonies of ants, termites, social wasps, and bees to
dominate competitively over solitary species throughout the Cenozoic.
Advanced sociality requires not just nestmate cooperation and
specialization but refined coordination and communication. Here we provide
independent evidence that 100-million-year-old Cretaceous ants in amber
were social, based on chemosensory adaptations. Previous studies inferred
fossil ant sociality from individual ants preserved adjacent to others. We
analyzed several fossil ants for their antennal sensilla, using original
rotation imaging of amber microinclusions, and found an array of antennal
sensilla, specifically for alarm pheromone detection and nestmate
recognition, sharing distinctive features with extant ants. Even though
Cretaceous ants were stem groups, the fossilized sensilla confirm
hypotheses of their complex sociality.