Forskergruppen for tidlig liv på Digermulhalvøya

Evolution of early biota and complex ecosystems took place during the Ediacara-Cambrian transition. A suite of stem-group bilaterian animals, vendobionts, radially organized organisms and inhabitants of the planktonic realm emerged in a succession of events leading to the increased diversity of the Cambrian seas. In Scandinavia this entire transition can only be studied on the Digermul Peninsula in northern Norway. Here about 3 000 m of siliciclastic sediments of nearly unprecedented preservation and completeness are preserved, spanning the Ediacara-Cambrian transition and continuing into the Lower Ordovician. 20 years ago Ediacara type fossils were found here, and during 2011 new Aspidella type organisms came to light. Well-preserved organic-walled microfossils give firm age constraints on the succession. Trace fossil abundance and preservation is exceptional. Treptichnus pedum and associated trilobed trace fossils in combination with occurrences of Granomarginata prima and the first report of Cochleatina in Scandinavia places the Ediacaran – Cambrian transition at the third cycle of the Manndraperelva Member (Stáhpogiedde Formation). The age of the lower part of the Stáhpogiedde Formation (Innerelva Member) is suggested to be younger than ca 560 Ma based on the presence of Aspidella, vendotaenids and possible simple trace fossils. The exceptional Digermul succession is thus in a central position for understanding the evolution and development of early complex ecosystems.

Team leader, Dr. Anette Högström (Tromsø University Museum) and collaborating scientist, Dr. Jan Ove R. Ebbestad (Museum of Evolution, Uppsala University) pose with slab containing dozens of the disc-shaped Ediacaran fossil called Aspidella.

Map of the study area on the Digermul Peninsula, Finnmark, Norway. FINANSIERT AV