Figure 1.

Scanning electron microscope images of microboring trace fossils (in order of abundance) prepared as epoxy resin casts from mollusc shells from the Sinemurian–Pliensbachian (Early Jurassic) of the Glasenbach section, Austria. (a) Semi-cylindrical resin cast of a belemnite rostrum exhibiting a large number of microborings; (b) the dominant fungal microboring Polyactina araneola, in modern seas produced by the fungus Conchyliastrum; (c) the aphotic index ichnotaxon Orthogonum lineare, producer unknown but most likely a fungus; (d) cluster of Flagrichnus profundus, produced by schizochytrid fungi; (e) Orthogonum giganteum, producer unknown; (f) Saccomorpha isp., presumed fungal trace; (g) Podichnus centrifugalis, attachment scar of a juvenile brachiopod pedicle; (h) Platydendrina convexa, producer unknown; (i) unknown dichotomously branching dendrinid microboring with affinity to the ichnogenus Abeliella. Scale bars equal 1 mm in (a), 10 µm in (b,d,f) and 100 µm in (c,e,g–i).