Early Cretaceous angiosperms and beetle evolution

The Coleoptera (beetles) constitute almost one–fourth of all known life-forms on earth. They are also among the most important pollinators of flowering plants, especially basal angiosperms. Beetle fossils are abundant, almost spanning the entire Early Cretaceous, and thus provide important clues to explore the co-evolutionary processes between beetles and angiosperms. We review the fossil record of some Early Cretaceous polyphagan beetles including Tenebrionoidea, Scarabaeoidea, Curculionoidea, and Chrysomeloidea. Both the fossil record and molecular analyses reveal that these four groups had already diversified during or before the Early Cretaceous, clearly before the initial rise of angiosperms to widespread floristic dominance. These four beetle groups are important pollinators of basal angiosperms today, suggesting that their ecological association with angiosperms probably formed as early as in the Early Cretaceous. With the description of additional well-preserved fossils and improvements in phylogenetic analyses, our knowledge of Mesozoic beetle–angiosperm mutualisms will greatly increase during the near future

Embodied Energy and Cost Optimization of RC Beam under Blast Load

Reinforced concrete (RC) structures not only consume a lot of resources but also cause continuing pollution. However, sustainable design could make RC structures more environmental-friendly. One important index for environmental impact assessment is embodied energy. The aim of the present study is to optimize the embodied energy and the cost of RC beam subjected to the blast loads. First, a general optimization procedure was described. Then, the optimization procedure was used to optimize the embodied energy and the cost of RC beams. Optimization results of the cost and the embodied energy were compared. It was found that the optimization results were influenced by the cost ratio nC (ratio of price of steel to price of concrete per unit volume) and the embodied energy ratio nE (ratio of embodied energy of steel to embodied energy of concrete per unit volume). An optimal design that minimized both embodied energy and cost simultaneously was obtained if values of nC and nE were very close

Mouthpart homologies and life habits of Mesozoic long-proboscid scorpionflies

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Mesozoic long-proboscid scorpionflies (Mesopsychoidea) provide important clues to ancient plant-pollinator interactions. Among them, the family Aneuretopsychidae is especially important because its mouthparts are vital to deciphering the early evolution of Mesopsychoidea and putatively the origin of fleas (Siphonaptera). However, the identification of mouthpart homologs among Aneuretopsychidae remains controversial because of the lack of three-dimensional anatomical data. Here, we report the first Aneuretopsychidae from Late Cretaceous Burmese amber, which have short maxillary palpi and elongate mouthpart elements consisting of one pair of galeae and one hypopharynx. Their mouthparts are identical to those of Pseudopolycentropodidae (= Dualulidae, new synonym) but are not homologous to those of Siphonaptera. Our phylogenetic analysis provides robust evidence for the debated monophyly of Mesopsychoidea. Our results suggest that the long-proboscid condition has most likely evolved once in Mesopsychoidea, independently from fleas, and further reveal the variety and complexity of mid-Cretaceous pollinating insects

Brood care in a 100-million-year-old scale insect

Behavior of extinct organisms can be inferred only indirectly, but occasionally rare fossils document particular behaviors directly. Brood care, a remarkable behavior promoting the survival of the next generation, has evolved independently numerous times among animals including insects. However, fossil evidence of such a complex behavior is exceptionally scarce. Here, we report an ensign scale insect (Hemiptera: Ortheziidae), Wathondara kotejai gen. et sp. nov., from mid-Cretaceous Burmese amber, which preserves eggs within a wax ovisac, and several freshly hatched nymphs. The new fossil is the only Mesozoic record of an adult female scale insect. More importantly, our finding represents the earliest unequivocal direct evidence of brood care in the insect fossil record and demonstrates a remarkably conserved egg-brooding reproductive strategy within scale insects in stasis for nearly 100 million years

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