High acoustic diversity and behavioral complexity of katydids in the Mesozoic soundscape.

Acoustic communication has played a key role in the evolution of a wide variety of vertebrates and insects. However, the reconstruction of ancient acoustic signals is challenging due to the extreme rarity of fossilized organs. Here, we report the earliest tympanal ears and sound-producing system (stridulatory apparatus) found in exceptionally preserved Mesozoic katydids. We present a database of the stridulatory apparatus and wing morphology of Mesozoic katydids and further calculate their probable singing frequencies and analyze the evolution of their acoustic communication. Our suite of analyses demonstrates that katydids evolved complex acoustic communication including mating signals, intermale communication, and directional hearing, at least by the Middle Jurassic. Additionally, katydids evolved a high diversity of singing frequencies including high-frequency musical calls, accompanied by acoustic niche partitioning at least by the Late Triassic, suggesting that acoustic communication might have been an important driver in the early radiation of these insects. The Early-Middle Jurassic katydid transition from Haglidae- to Prophalangopsidae-dominated faunas coincided with the diversification of derived mammalian clades and improvement of hearing in early mammals, supporting the hypothesis of the acoustic coevolution of mammals and katydids. Our findings not only highlight the ecological significance of insects in the Mesozoic soundscape but also contribute to our understanding of how acoustic communication has influenced animal evolution.

Effects of lipid extraction on stable isotope ratios of carbon and nitrogen in muscles of freshwater fish.

The extraction of lipids by the Folch method from the muscles of all the fish studied led to statistically significant differences in the values of δ15N. At the same time, lipid extraction led to a statistically significant increase in δ13C in pike and roach, and to a statistically insignificant decrease in δ13C in perch and bream. Thus, lipid extraction cannot serve as a universal method of sample preparation for the analysis of the isotopic composition of carbon (13C/12C) and nitrogen (15N/14N) in fish muscles. The differences between the δ13C values in the samples before and after lipid extraction were statistically investigated by different models. It is shown that mathematical correction method models can be used, but the results are depending on the fish types.

New anaxyelids (Hymenoptera: Anaxyelidae) from the Cretaceous of Asia.

Four new genera and five new species of anaxyelids are described from the Cretaceous of Asia: Mangus magnus gen. et sp. nov. from the Aptian of Mongolia (Bon-Tsagan), Urosyntexis undosa sp. nov., Parasyntexis khasurtensis gen. et sp. nov., both from the Early Cretaceous of Transbaikalia (Khasurty), Dolichosyntexis transbaikalicus gen. et sp. nov. from the Hauterivian-Barremian of Transbaikalia (Baissa), and Curiosyntexis magadanicus gen. et sp. nov. from the mid-Upper Cretaceous of NE Siberia (Obeshchayushchiy). Early Cretaceous is the time of the highest diversity of Anaxyelidae. In this epoch these sawflies are represented with all four subfamilies comprising the group. In Late Cretaceous anaxyelid diversity and abundance rapidly decrease and they are represented with the only subfamily Syntexinae. The anaxyelid collection of Palaeontological Institute (Moscow), the most representative collection of fossil anaxyelids in the world, has been completely revised, identified and described. The list of identifications is provided.

Forgotten giants: new Anaxyelidae (Hymenoptera) from the Jurassic of Karatau.

Three new species of Anaxyelidae from the Middle-Upper Jurassic of Karatau (Kazakhstan) are described: Brachysyntexis tenebrosa sp. nov., B. tigris sp. nov., and Kulbastavia grandis sp. nov. By the size of the body, B. tenebrosa and K. grandis are the largest Jurassic species of the family. In the Jurassic period, the Anaxyelidae were represented only by the subfamily Anaxyelinae. They were found in three localities: Daohugou (China, 17 specimens), Karatau (Kazakhstan, 27 specimens) and Khoutiyn-Khotgor (Mongolia, 1 specimen). A list of all known Jurassic findings of Anaxyelidae from the collections of the Palaeontological Institute (Moscow) is given.