DOI: 10.3897/asp.81.e109833

Authors: Pavel Sroka, Jakub Prokop

Abstract: The stonefly suborders Arctoperlaria and Antarctoperlaria reflect the current division of the diversity of this insect order between the Northern and Southern Hemispheres. However, there are several exceptions to this pattern, the most notable being the family Notonemouridae, which is phylogenetically deeply subordinate within the northern Arctoperlaria, but distributed in South Africa, South America, and Australia. Various hypotheses have been proposed regarding the circumstances of their dispersal to the south. Some estimated their origin as relatively recent, with long-distance dispersal to the southern continents in the Late Cretaceous or early Paleogene. On the other hand, fossils of Notonemouridae have been dated to the Middle Jurassic, proving the lineage is very ancient. However, all known notonemourid fossils originate from Asia and the timing of their dispersal to the south cannot be precisely estimated. Here we report new fossil stoneflies from the Late Jurassic Talbragar Fish Beds, Australia, described as Talbragaria australis gen. et sp. nov. and attributed to Notonemouridae. This finding represents the first fossil evidence of the northern suborder Arctoperlaria in the Southern Hemisphere, and confirms the north-to-south dispersal of Notonemouridae across Pangea prior to the continental break-up.

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DOI: 10.3897/asp.80.e82549

Authors: Zhi-Teng Chen

Abstract: The larval stage is an essential part of the life history of stoneflies and can provide substantial biological and evolutionary information. However, well-preserved fossils of larvae are sparse. Herein, the larval morphology of a new extinct stonefly, Kachinoperla zwicki gen. et sp. nov., is described based on its exuvia in mid-Cretaceous Kachin amber from northern Myanmar (98.79±0.62 Ma). The new stonefly also represents a new family, Kachinoperlidae fam. nov. according to its unique characters. Kachinoperlidae can be distinguished from other stonefly families by the following larval characters: predaceous mouthparts, subequal glossae and paraglossae, subequal maxillary and labial palps, reduced apical maxillary palpomere, trapezoidal pronotum, banded and semicircular wing pads, invisible notal contour, absent thoracic gills, shortest first two tarsomeres, and strongly projected abdominal tergum 10. The morphological comparison and phylogenetic analysis suggested the new family as a basal lineage within Systellognatha. Evolutionary implications implied by the larval characters are also discussed.

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