New species of Paraodontomma from mid-Cretaceous Burmese amber with muscle tissue preservation (Coleoptera: Archostemata: Ommatidae)

Abstract

The third member of the extinct ommatid genus Paraodontomma is reported from mid-Cretaceous Burmese amber. Our observation confirms the transverse ridges on elytra as a diagnostic character for the genus. Paraodontomma leptocristatum sp. nov. differs from previously reported congeners mainly in head subquadrate and without prominent protuberances, pronotal disc without prominent ridges, elytral ridges indistinct, and teeth along elytral margins not forming a wavy pattern. Musculature is preserved in the newly discovered specimen of P. leptocristatum, which further demonstrates the preservation potential and irreplaceable value of amber fossils.

Application of confocal laser scanning microscopy to the study of amber bioinclusions

“…In some amber specimens, fluorescence is produced only around the border between the fossil and the amber (e.g., Fig. 8A; Li et al, 2021cLi et al, , 2021d. In this case, maximum intensity projection can generate ideal stacking results, since the maximum intensity is obtained exactly on the surface of the fossil (Fig.…”

The First Reconstruction of the Head Anatomy of a Cretaceous Insect, †Gerontoformica gracilis(Hymenoptera: Formicidae), and the Early Evolution of Ants

“…µ-CT scans can reveal fine morphological details of fossils that would have otherwise been inaccessible, including internal features (e.g., Dunlop et al 2011, van de Kamp et al 2014. Grimaldi et al (2019) and Li et al (2021) were the first to show internal soft tissue of insect fossils (an apoid wasp and archostematan beetle, respectively) from the mid-Cretaceous-dated (Albian-Cenomanian boundary) Kachin amber (~99 Mya) using µ-CT-scans, but the preservation of their specimens and scan resolution were not sufficient for 3D reconstruction. The only example of an almost complete reconstruction of the internal anatomy of an insect fossil is †Mengea tertiaria (Menge, 1866) (Mengeidae) from Baltic amber, a species belonging to the stem group of the endoparasitic Strepsiptera (Pohl et al 2010).…”

“…They reconstructed the flight musculature of the best-preserved specimen in 3D. Li et al (2021) used µ-CT scanning to reveal internal soft tissue preservation of an archostematan beetle (Paraodontomma) embedded in Burmese amber. Although they were not able to provide a detailed reconstruction due to limited resolution, poor preservation, and taphonomic artefacts, they tentatively identified a few muscles of possible systematic relevance, showing a thoracic bundle that is likely a plesiomorphy retained by Archostemata but missing in the other beetle suborders (Beutel and Haas 2000).…”

Unparalleled details of soft tissues in a Cretaceous ant

“…Muscle tissue has also been reported from Kachin ambers in the recent years. These include the dorsoventral ight muscles of a stinging wasp (Grimaldi et al, 2019), the muscular bundles in the metathorax of a beetle (Li et al, 2021), and those connecting the thorax and the abdomen of a stem ant (Boudinot et al, 2021). By contrast, muscles in the head of the animals are barely recovered.…”