Reaching across the ocean of time: A midge morphotype from the Cretaceous of Gondwana found in the Eocene Baltic amber

Abstract

Non-biting midges (Chironomidae) have a fossil record reaching back into the Triassic. The non-biting midge ingroup Libanochlites Brundin, 1976, was so far known from a single species. Fossil specimens of this species came from the Cretaceous of Gondwana, more precisely from Lebanese amber (130 million years). A new species, based on fossils in Eocene Baltic amber, is so similar to the so far single species of Libanochlites that it can only be attributed to this group. This is extending the known geological range of this so far unique morphology by 80 million years. This provides us with the first case of the long-term survival ("Bradytely") of a distinct Mesozoic morphotype of a representative Diptera with aquatic larvae into the Cenozoic. Bradytely is a phenomenon describing evolutionary stasis. This represents a case of bradytely in insects with aquatic larvae and has an impact on our understanding of the Cretaceous terrestrial revolution. Primarily, this record allows us to determine conditions which are permitting the survival of the Mesozoic aquatic insects into the Palaeogene. The conditions are related to the bradytely of the insects with aquatic larvae in the temperate, subtropical forest.

Ankothrips, the most ancient extant thrips genus (Thysanoptera, Melanthripidae)

“…The non‐biting midge (Chironomidae, Diptera) genus Libanochlites Brundin, 1976 is an example of a long‐living group now extinct, presenting a stable morphology over a geological range of 80 million years, thought to have aquatic life phases, surviving the drastic changes in freshwater ecosystems due to the Cretaceous Terrestrial Revolution; Baranov et al . (2019) hypothesized that the species used oligotrophic boreal lakes or streams or rivers as refugia for survival.…”

Diversity of culicomorphan dipterans in the Eocene Kishenehn Konservat-Lagerstätte (Montana, USA) and its palaeoecological implications

“…Yet, to enhance the understandability for non-experts, we amended some of the special morphological terms with more general terms. As Insecta is an accepted ingroup of Crustacea s.l., 'crustacean' terms given in square brackets were necessary to provide a wider frame of correspondence (Baranov et al, 2019a(Baranov et al, , 2019b(Baranov et al, , 2020. In this paper, we deal mostly with morphotypes, i.e., distinct morphological groups of organisms.…”

The Morphological Diversity of Dragon Lacewing Larvae (Nevrorthidae, Neuroptera) Changed More over Geological Time Scales Than Anticipated

“…The morphology of dragon lacewings, including that of the larvae, seemed more or less unchanged since the Cretaceous (a phenomenon fairly common in some groups of Holometabola across all life stages, see [44]). This result is partly surprising as the group is understood as a mere relict group.…”