1. Palaeoecosystems Group; Department of Earth Sciences; Durham University; Durham DH1 3LE UK
2. Department of Geology; Lund University; Sölvegatan 2 Lund 223 62 Sweden
3. Department of Geology; National Museum of Wales; Cathays Park Cardiff CF10 3NP UK
4. Department of Earth Sciences (Palaeobiology); Geocentrum; Uppsala University; Uppsala 752 36 Sweden
5. Early Life Institute & Department of Geology; State Key Laboratory for Continental Dynamics; Northwest University; Xi'an 710069 China