Fossil social insects

Eusocial behavior has evolved at least 18 times and 13 of these origins are among insect linages. When did the first eusocial insects appear? Which social insect lineages are the oldest? Specimens entombed in amber and rock chronicle ancient origins, extinctions, diversification, and in some cases even behavior. The paleontological history of social insects extends into the Early Cretaceous over 130 million years ago. Owing in part to their abundance and ubiquity in some terrestrial environments, ants and termites in particular exhibit a rich fossil record spanning hundreds of described species. Social bees and wasps are also preserved in the rock record, providing insight into the timing of their evolution as well as their complex biogeographic history. Here, we will briefly survey the oldest known fossils for extant lineages, the earliest evidence for eusociality, and select cases of striking extinction.