Behaviors are challenging to reconstruct for extinct species, particularly the nature and origins of acoustic communication. Here we unravel the song of Archaboilus musicus Gu, Engel and Ren sp. nov., a 165 million year old stridulating katydid. From the exceptionally preserved morphology of its stridulatory apparatus in the forewings and phylogenetic comparison with extant species, we reveal that A. musicus radiated pure-tone (musical) songs using a resonant mechanism tuned at a frequency of 6.4 kHz. Contrary to previous scenarios, musical songs were an early innovation, preceding the broad-bandwidth songs of extant katydids. Providing an accurate insight into paleoacoustic ecology, the low-frequency musical song of A. musicus was well-adapted to communication in the lightly cluttered environment of the mid-Jurassic forest produced by coniferous trees and giant ferns, suggesting that reptilian, amphibian, and mammalian insectivores could have also heard A. musicus' song.call evolution | Tettigoniidae | bushcricket | biomechanics | biological asymmetry K atydids produce species-specific calling songs that form part of the acoustic ecology of tropical forests (1, 2). The rubbing of a toothed vein on one wing against a plectrum on the other wing results in sound production by stridulation, exploiting resonant (musical) (3, 4) or nonresonant (broadband) (4, 5) biophysical mechanisms, depending on the species. Which of these two mechanisms represents ancestral sound production remains a key question in the evolution of insect acoustic communication (6)(7)(8). Here, we reconstruct the song of a katydid fossil with exceptionally well-preserved stridulatory structures, and find that musical singing at low frequencies was already established by the middle Jurassic (165 Ma). We describe this specimen as Archaboilus musicus, from the extinct family Haglidae (Orthoptera), a group basal to all extant katydids (9, 10). These findings imply that A. musicus was nocturnal, and that its call was adapted for long-range communication in an environment with light clutter (11). A recent paleobotanical reconstruction of the geometry, vegetation density, and biomass of the Jurassic Forest from northwest China (12) reveals an environment populated by coniferous trees (e.g., Araucaria) with nearest neighbor distances ranging from 1.5 to 20.3 m, and giant ferns (e.g., Angiopteris, Osmunda, and Caniopteris) occupying the lower layers of the understory forest. This forest architecture indicates a sparse vegetation density that is acoustically compatible with the proposition that the song frequency of A. musicus was well adapted to long-distance communication close to the ground. Such a forested environment would also enable long-range acoustic signaling and communication by other animals (e.g., amphibians, reptilians) as well as a variety of arthropod species (13). Systematic PaleontologyInsecta Linnaeus, 1758; Orthoptera Olivier, 1789; Haglidae Handlirsch, 1906; Cyrtophyllitinae Zeuner, 1935; Archaboilus Martynov, 1937.Archaboilus musicu...

A new specimen of Qilianiblatta namurensis Zhang et al., 2012 composed of paired forewings and hind wings is described. Observed differences between left and right forewings allow conjectures of primary homology in forewing venation of Blattodea and Pennsylvanian 'cockroachoids' to be clarified: (1) the radial system is organized with distal branches of RA translocated to RP in Q. namurensis and in crown-Blattodea; and (2) branches of the median system are translocated to/fused with CuA in Pennsylvanian 'cockroachoids'. The arculus observed in Pennsylvanian 'cockroachoids' is most likely composed of M veinlets fusing with CuA.

Objective To determine CT's role in the early detection of COVID-19 infection and serial CT changes in the disease course in patients with COVID-19 pneumonia. Methods From January 21 to February 18, 2020, all of the patients who were suspected of novel coronavirus infection and verified by RT-PCR tests were retrospectively enrolled in our study. All of the patients underwent serial RT-PCR tests and serial CT imaging. The temporal relationship between the serial RT-PCR results (negative conversion to positive, positive to negative) and serial CT imaging was investigated, and serial CT changes were evaluated. Results A total of 155 patients with confirmed COVID-19 pneumonia were evaluated. Chest CT detection time of COVID-19 pneumonia was 2.61 days earlier than RT-PCR test (p = 0.000). The lung CT improvement time was significantly shorter than that of RT-PCR conversion to negative (p = 0.000). Three stages were identified from the onset of the initial symptoms: stage 1 (0-3 days), stage 2 (4-7 days), and stage 3 (8-14 days and later). Ground glass opacity (GGO) was predominant in stage 1, then consolidation and crazy paving signs were dramatically increased in stage 2. In stage 3, fibrotic lesions were rapidly increased. There were significant differences in the main CT features (p = 0.000), number of lobes involved (p = 0.001), and lesion distribution (p = 0.000) among the different stages. Conclusion Chest CT detected COVID-19 pneumonia earlier than the RT-PCR results and can be used to monitor disease course. Combining imaging features with epidemiology history and clinical information could facilitate the early diagnosis of COVID-19 pneumonia. Key Points • The chest CT detection time of COVID-19 pneumonia was 2.61 days earlier than that of an initial RT-PCR positive result (t = − 7.31, p = 0.000). • The lung CT improvement time was significantly shorter than that of RT-PCR conversion to negative (t = − 4.72, p = 0.000). • At the early stage (0-3 days), the CT features of COVID-19 were predominantly GGO and small-vessel thickening; at stage 2 (4-7 days), GGO evolved to consolidation and crazy paving signs. At stage 3 (8-14 days and later), fibrotic lesions significantly increased, accompanied by consolidation, GGO, and crazy paving signs.

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