Plant-Arthropod Associations from the Lower Miocene of the Most Basin in Northern Bohemia(Czech Republic):A Preliminary Report

Terrestrial plants and insects currently account for the majority of the Earth＇s biodiversity, and approximately haft of insect species are herbivores. Thus, insects and plants share ancient associations that date back more than 400 Myr. However, investigations of their past interactions are at the preliminary stages in Western Europe. Herein, we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstaette Bflina Mine in the Most Basin, Czech Republic. This site provides a unique view of the Neogene freshwater ecosystems. It has long been studied by scientists working in different branches of sedimentology, paleobotany, and paleozoology. The fossils are preserved in three characteristic horizons overlaying the coal seam （Clayey Superseam Horizon, Delta Sandy Horizon, and Lake Clayey Horizon）, reflecting paleoenvironmental changes in a short time period of development. The trace fossils are classified as functional feeding groups or ＂guilds＂, without searching for a direct cause or a recent analog host relation. Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf ＂morphotypes＂. Deciduous plant-host taxa, and those with a chartaceous texture typical of riparian habitats, were frequently damaged, such as Populus, recorded with two species Populus zaddachii and Populus populina （57.9% and 31% herbivory levels, respectively）, followed by Acer, Alnus, and Carya, averaging almost 30% of damaged leaves/leaflets. There has been evidence of 60 damage types （DT） representing all functional feeding groups recorded at the Bflina Mine, including 12 types of leaf mines and 16 gall- type DT. In total, Lower Miocene of the Lagerstaette Bilina Mine exhibits a high level of external foliage feeding types （23.7%）, and a low level of more specialized DT, such as galls （4.3%） and leaf mines （〈1%）. A broader comparison based on DT of the main sedimentary environments shows significance supporting different biomes by frequency of damage levels and DT diversities.

Fossil Hydrophilid Beetles (Coleoptera:Hydrophilidae) of the Late Oligocene Rott Formation(Germany)

Fossil water scavenger beetles （Coleoptera： Hydrophilidae） of the latest Oligocene Rott Formation are revised, based on the examination of the type specimens, as well as numerous additional material from Statz （Los Angeles） and Kastenholz （Bonn） collections. Seven hydrophilid species are recognized, five of which are reliably attributed to the following genera： Berosus morticinus （von Heyden and von Heyden, 1866）, Paracymus excitatus （von Heyden and yon Heyden, 1866）, Paracymus sp., Hydrobiomorpha fraterna （von Heyden, 1859）, and Hydrophilus rottensis （Statz, 1939）. Coccinella？protogaeae Germar 1837 is attributed to the subtribe Hydrophilina, and Cymbiodyta？ austera Statz 1939 to the subfamily Hydrophilinae. Hydrous ebeninus Statz 1939 and Paracymus excitatus （form 3） are excluded from the Hydrophlloidea. Berosus capitatus Statz 1939 is synonymized with Berosus morticinus, and Hydrous neptunus von Heyden and von Heyden 1866 with Hydrobiomorphafraterna. Lectotypes of Philydrus morticinus von Heyden and von Heyden 1866 and Hydrous ebeninus Statz 1939 are designated. The significance of the hydrophllid fossils for paleoecological reconstructions of the former Rott Lake is briefly discussed.