Nyker Group
The Nyker Group is a group of geological formations from the Early Cretaceous, about 146 to 140 million years ago. It is on the island of Bornholm, Denmark. It includes the Rabekke, Robbedale and Jydegaard Formations.[1]
| Nyker Group Stratigraphic range: Latest Jurassic-Early Cretaceous ~146–140 Ma | |
|---|---|
| Type | Geological unit |
| Sub-units | Rabekke, Robbedale & Jydegaard Formations |
| Underlies | Arnager Greensand Formation |
| Overlies | Bagå Formation |
| Lithology | |
| Primary | Claystone, sandstone |
| Location | |
| Region | Bornholm |
| Country |  |
Rabekke Formation
The Rabekke Formation is the lowermost formation of the Nyker Group. It dates to about 146 to 145 million years ago, at the Jurassic-Cretaceous boundary. The formation has the significance of having the first Scandinavian mammal, Sunnyodon notleyi, uncovered from it. Many crocodilomorphs and other vertebrates have been recovered from it.[2]
Robbedale Formation
The Robbedale Formation is the middle formation of the Nyker Group. It dates to about 145 million years ago. No vertebrate fossils have been recovered from the formation.[1]
Jydegaard Formation
The Jydegaard Formation is the uppermost formation of the Nyker Group. It dates to around 145 to 140 million years ago. The first dinosaur found on Denmark, Dromaeosauroides bornholmensis, was discovered in this formation.[1] Many vertebrates have been recovered from it.[2]
References
- Bonde, N.; Christiansen, P. (2003). "New dinosaurs from Denmark". Comptes Rendus Palevol. 2: 13. doi:10.1016/S1631-0683(03)00009-5.
- Milàn, J.; Rasmussen, B.W.; Bonde, N. (2012) "Coprolites with prey remains from coprophagous organisms from the Lower Cretaceous (Late Berriasian) Jydegaard Formation of Bornholm, Denmark". New Mexico Museum of Natural History and Science. Bulletin 57: 235-240