title: Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia.
abstract: Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia). The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation) of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.
authors: Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland.
authors: Krzysztof
authors: K
authors: Owocki
authors: Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland.
authors: Barbara
authors: B
authors: Kremer
authors: Faculty of Chemistry, Warsaw University, Warsaw, Poland.
authors: Beata
authors: B
authors: Wrzosek
authors: Faculty of Chemistry, Warsaw University, Warsaw, Poland.
authors: Agata
authors: A
authors: Królikowska
authors: Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland.
authors: Józef
authors: J
authors: Kaźmierczak
mesh_terms: D000818:Animals; D018441:Biofilms; D001842:Bone and Bones / Q000382:microbiology*; D003460:Crystallization; D003889:Desert Climate; D025061:Dinosaurs; D005580:Fossils / Q000382:microbiology* / Q000648:ultrastructure; D005658:Fungi / Q000302:isolation & purification* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D025301:Hyphae / Q000648:ultrastructure; D007501:Iron / Q000032:analysis*; D008345:Manganese / Q000032:analysis*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008986:Mongolia; D025282:Mycelium / Q000648:ultrastructure; D013059:Spectrum Analysis, Raman
chemical_list: C083456:ferro-manganese alloy; D008345:Manganese; D007501:Iron