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

Abstract

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.

Evolution and systematics of the Aculeata and kin (Hymenoptera), with emphasis on the ants (Formicoidea: †@@@idae fam. nov., Formicidae)

“…In terms of species-level diversity, the crown Formicidae are one, two, and three orders of magnitude more diverse than Isoptera, obligately eusocial Apidae (Apini, Meliponini), and obligately eusocial Vespidae (Vespinae), respectively (Table 6). The sense that ants are unique also strengthens when accounting for time, as the crown clades of Isoptera and Formicidae both survived the End Cretaceous crisis and may have been coeval in their transition to superorganismality (Evangelista et al 2019), and even more so given other estimates of a Jurassic crown age for Isoptera (e.g., Legendre et al 2015, Bourguignon et al 2015, Jouault et al 2021c.…”

Termite Valkyries: Soldier-Like Alate Termites From the Cretaceous and Task Specialization in the Early Evolution of Isoptera

“…Soldiers are present in almost all termite species and are considered to be an apomorphy of termites (e.g., Hare, 1937;Noirot and Pasteels, 1987;Roisin, 2000). Then, it is possible that Valkyries do not predate sterile soldiers, although the oldest known Valkyrie, reported herein, is older than the first occurrences of true apterous soldiers (e.g., Engel et al, 2016;Zhao et al, 2020;Jouault et al, 2021). But given the nature of the fossil record, particularly for Isoptera, such absences of occurrence cannot be equated with evidence of actual absence.…”

The oldest Cenozoic ant fossil: †Tyrannomeciagen. nov. (Formicidae: Myrmeciinae) from the Palaeocene Menat Formation (France)

“…These phylogenies rely on fossil calibration (node-dating) in which the fossils are not directly integrated into the tree topology, as they are in tip-or total-evidence dating approaches (e.g. Ronquist et al 2012;Jouault et al 2021). In node-dating approach, the fossils are used to calibrate a node within the topology based on the ages of the fossils.…”