Deep-time evolution and biogeography of a transitional lacewing lineage with Gondwanan origin

Understanding macroevolution requires integrating morphological and molecular data from fossil and extant taxa to reconstruct phylogenies, trait evolution and biogeographic history. However, the macroevolutionary process since its deep-time origin via a total-evidence approach has been investigated only in a limited number of groups. Here we present the first total-evidence phylogenetic and biogeographic analyses of Dilaridae, a key transitional group of Neuroptera, integrating high-resolution 3D morphological reconstructions of Cretaceous stem-group taxa. We describe a new genus and four new species from the Kachin amber, that is, †Palaeonallachius fangyuani gen. et sp. nov., †Coronidilar jiaxiaoae sp. nov., †Cretodilar zhiqiae sp. nov. and †Cretodilar galaxias sp. nov., which provide valuable morphological data for phylogenetic inference. Comparative analyses using alternative sampling strategies (extant-only or total-evidence) demonstrate the advantages of integrating fossil data in phylogenetic inference, divergence-time estimation and ancestral range reconstruction. Our results support a Gondwanan origin of Dilaridae associated with the West Burma Block, followed by dispersal into Laurasia via northward-drifting Gondwanan landmasses and possible trans-Antarctic dispersal since the Jurassic. The absence of extant dilarids in Australasia is likely due to extinction. These findings highlight the importance of fossil integration in resolving deep-time evolution and the role of Gondwanan dynamics in shaping insect biogeography.