Paleoenvironmental Interpretation of a Fossil Locality from the Late Triassic of Germany

Havlik, P., Aiglstorfer, M., Atfy, Haytham, E. and D. Uhl, Dieter. 2013. A peculiar bonebed from the Norian Stubensandstein (Löwenstein Formation, Late Triassic) of southern Germany and its palaeoenvironmental interpretation. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 269 : 321-337
DOI: http://dx.doi.org/10.1127/0077-7749/2013/0354

Abstract - Despite the abundance of Triassic outcrops in S Germany knowledge about continental ecosystems from the Norian is rather scarce so far for this region. A new fossil-bearing site from the Lower Löwenstein Formation (Unterer Stubensandstein; Norian) of north-eastern Baden-Württemberg (SW Germany), discovered in 2011, yielded disarticulated vertebrate remains together with a moderately diverse palynoflora, ichnofossils and gymnospermous charcoal. These remains are accumulated in a bonebed layer. Palynomorphs support a Late Triassic age of the source sediment, showing a high diversity of conifers. The new site provides the second conclusive evidence for wildfires in the Norian of Europe and the first record of phytosaurs from Schwäbisch Gmünd. Based on sedimentological evidence and taphonomical interpretations of the charcoal remains, it seems possible that the bonebed can be regarded as the result of increased erosion following catastrophic wildfire.

Rhaetian Ichnology and Geochemistry of the Westbury Formation, England

Allington-Jones, L., Braddy, S. J., and Trueman, C. N. 2010. Palaeoenvironmental implications of the ichnology and geochemistry of the Westbury Formation (Rhaetian), Westburyon- Severn, South-West England. Palaeontology 53:491-506. doi: 10.1111/j.1475-4983.2010.00947.x


Abstract - The Westbury Formation (Rhaetian) beds of Westbury Garden Cliff, Westbury-on-Severn, west of Gloucester, Britain, show an unusual combination of features. Both deep water and emergent characteristics are present within the sediments and the trace fossils. The ichnoassemblage consists of abundant Selenichnites, Planolites beverlyensis and Lockeia with rarer Oniscoidichnus, Chondrites, Rhizocorallium irregulare, Taenidium serpentium, an unusual form of Walcottia and Merostomichnites-like traces. These trace fossils display an interesting relationship with the sediments: low-energy Cruziana ichnofacies is found within high-energy sandstones. The sandstones are interbedded with laminated mudstones, apparently deposited in deep water, but some aspects of the ichnoassemblage, preservation and sedimentation indicate shallower water. One new trace fossil, Radichnus allingtona igen. et isp. nov., closely resembles the traces of modern fiddler crabs and imply emergence, by analogy. This ichnofauna is similar to early stage disaster colonisation in recent experiments in Long Island Sound (south of Connecticut, USA) and with storm influenced deposits within the Cardium Formation (Seebe, Alberta, Canada). This indicates a lagoonal environment with influxes of sand and oxygen. Total organic carbon levels were found to fluctuate greatly between stratigraphic layers but remained relatively high. This implies low oxygen conditions. The abundance of sulphur (in pyrite) also supports an interpretation of anoxic conditions, and low sedimentation rates within the shale layers. A restricted shallow basin or lagoonal environment is proposed for the palaeoenvironment, with fluctuating oxygen influencing diversity.