New trace fossils of termites (Insecta: Isoptera) from the late Eocene‐early Miocene of Egypt, and the reconstruction of ancient isopteran social behavior

Three new ichnogenera and five new ichnospecies are described for new trace fossils of termitaria (including associated gallery systems) of subterranean termites from upper Eocene through lower Miocene rocks of northern Egypt. All but two ichnospecies (Krausichnus trompitus, ichnogen, and ichnosp. nov., and A’, altus, ichnosp. nov.) show varying degrees of affinity to nests of the extant subterranean termite species Sphaerotermes sphaerothorax (Termitidae, Macro‐termitinae).

Termitichnus qatranii (Bown, 1982) is divided into two ichnospecies, the previously named T. qatranii, and a more generalized form, T. simplicidens, ichnosp. nov. Vondrichnus obovatus, ichnogen. and ichnosp. nov., is named for simple, possibly macrotermitine nests with oblate form, and Fleaglellius pagodus, ichnogen. and ichnosp. nov., records a nest form similar to V. obovatus, but one in which successive vertical growth by chamber apposition has produced a subterranean, tower‐like structure, reminiscent of that built by extant, epigeous Cubitermes. Krausichnus trompitus, ichnogen. and ichnosp. nov., and A’, altus, ichnosp. nov., record two unique nest architectures probably produced by unknown but related species of humivorous termites. The nest architecture expressed by Krausichnus is of wholly unknown affinity and is only distantly related in form to the ichnofossils of other termite nests known from the Tertiary of Egypt.

Study of the architecture of the nests of these ancient termites reveals details important in reconstructing the phylogeny of termite nests and documents two novel blueprints for chamber expansion and society budding in what were probably primitive Macrotermi‐tinae. It also indicates that at least two constructed edifices, earlier known only as epigeous manifestations of extant termite species, were almost certainly first developed by species living underground.

The extant Macrotermitinae are a subfamily of termites originally believed to have evolved in the post‐Eocene of the Ethiopian biogeo‐graphic region. We offer fossil evidence of four distinct, possibly macrotermitine structures from upper Eocene rocks. This evidence suggests that this termite subfamily (or at least their peculiar mode of nest construction) might have evolved considerably earlier, as it is already well established and exhibits several variants by the late Eocene in Egypt.