Rhuddanian
Axis scale: millions of years ago.
In the geologic timescale, the Rhuddanian is the first age of the Silurian period and of the Llandovery epoch. The Silurian is in the Paleozoic era of the Phanerozoic eon. The Rhuddanian age began 443.7 ± 1.5 Ma and ended 440.8 ± 1.2 Ma (million years ago). It succeeds the Himantian Age (the last age of the Ordovician Period) and precedes the Aeronian age.[3]
GSSP
The GSSP for the Silurian is located in a section at Dob's Linn in an artificial excavation created just north of the Linn Branch Stream.Two lithological units (formations) occur near the boundary. The lower is the Hartfell Shale (48m thick), consisting chiefly of pale gray mudstone with subordinate black shales and several interbedded meta-bentonites. Above this is the 43m-thick Birkhill Shale, which consist predominantly of black graptolitic shale with subordinate gray mudstones and meta-bentonites.[4]
Palaeontology
Agnathans
| Agnathans of the Rhuddanian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Rhuddanian-Telychian | ||||
Molluscs
Cephalopods
| Cephalopods of the Rhuddanian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Dapingian-Homerian | ||||
See also
References
- ↑ Jeppsson, L.; Calner, M. (2007). "The Silurian Mulde Event and a scenario for secundo—secundo events". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 93 (02): 135–154. doi:10.1017/S0263593300000377.
- ↑ Munnecke, A.; Samtleben, C.; Bickert, T. (2003). "The Ireviken Event in the lower Silurian of Gotland, Sweden-relation to similar Palaeozoic and Proterozoic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 195 (1): 99–124. doi:10.1016/S0031-0182(03)00304-3.
- ↑ "GSSP Table - All Periods". International Commission on Stratigraphy. Retrieved 15 September 2018.
- ↑ "GSSP for the Rhuddanian Stage". International Commission on Stratigraphy.