The Pangean journey of ‘south forestflies’ (Insecta: Plecoptera) revealed by their first fossils

The ‘south forestflies’ (Notonemouridae) are known from the southern hemisphere. However, their successive closest sister-groups all occur in the northern hemisphere, suggesting a north-to-south migration at some stage of their evolution. No reliable fossil remains that would provide age constraints for this event have been identified. According to previously published divergence date estimates, the group arose recently (65–98 Ma), implying a late transcontinental dispersal. Here, we describe a new fossil insect, Paranotonemoura zwicki Cui & Béthoux sp. nov. (Daohugou, China), and revise Paranotonemoura fidelis Sinitshenkova, 1987 comb. nov. (Bakhar, Mongolia), both of Jurassic age (c. 165 Ma). Based on the study of their wing venation pattern and of that of extant ‘south forestflies’, we demonstrate that the fossils belong to this group, and therefore are its first fossils. Our discovery demonstrates that the lineage is much more ancient than previously estimated. Plausible scenarios on the origin, migration and partial extinction are proposed based on the dispersal abilities of these insects and palaeogeographical reconstructions during the Mesozoic. We assume that the north-to-south migration took place between 220 and 160 Ma.

http://zoobank.org/urn:lsid:zoobank.org:pub:66E22602-FE0D-4641-AB14-D8CB129D8F67