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.真社会性（eusociality）这种高级社会行为在演化层面具有深远意义，它使得蚂蚁、白蚁、社会性胡蜂与蜜蜂的集群在整个新生代（Cenozoic）时期均可在竞争中压制独居物种。高级社会性不仅要求巢友间的合作与职能特化，更离不开精细化的协作与信息交流。本研究基于化学感应适应性（chemosensory adaptations），为琥珀中保存的1亿年前白垩纪（Cretaceous）蚂蚁具有社会性提供了独立佐证。既往研究多通过相邻保存的单只化石蚂蚁，推断其所属类群的社会性。我们借助琥珀微内含物（amber microinclusions）的原始旋转成像（rotation imaging）技术，对多件化石蚂蚁的触角感器（antennal sensilla）开展分析，结果发现了一系列专门用于告警信息素（alarm pheromone）检测与巢友识别（nestmate recognition）的触角感器，其特征与现生蚂蚁（extant ants）的同类结构高度相似。尽管白垩纪蚂蚁属于基干类群（stem groups），但这些石化的触角感器证实了其具备复杂社会性的相关假说。