Revising dating estimates and the antiquity of eusociality in termites using the fossilized birth-death process

Deciphering the timing and tempo of lineage diversification of organisms has greatly benefited from advances in Bayesian phylogenetic analyses using morphological data. Those advances, however, have not been used for termites despite a rich fossil record. Here, we estimate divergence times for living and fossil termites using the fossilized birth-death (FBD) process on a previously published morphological matrix expanded with two new fossils that we describe (see Appendices S1 and S2). Those fossils, based on soldier specimens, are the mid-Cretaceous mastotermitid Milesitermes engeli gen. et sp. nov., and the Middle Eocene Reticulitermes grimaldii sp. nov. The latter is the oldest occurrence of a Rhinotermitidae soldier and the first termite soldier described from Baltic amber. Our dating estimates provide new stem-ages and crown-ages for termites, suggesting older ages than previously thought for several lineages. Importantly, crown-Isoptera - and, therefore, eusociality - may have arisen approximately 200 Ma. We conclude with further directions to keep improving our understanding of the timing of differentiation in termites.

Automated summary

Deciphering the timing and tempo of lineage diversification of organisms has greatly benefited from Bayesian phylogenetic analyses using morphological data, although termites have not been included. The study estimated divergence times for living and fossil termites, providing new insights into the age of termites and suggesting an earlier origin of eusociality. The findings suggest directions for further research to improve understanding of termite differentiation timing.