Givetian
The Givetian is one of two faunal stages in the Middle Devonian period. It lasted from 387.7 million years ago to 382.7 million years ago. It was preceded by the Eifelian stage and followed by the Frasnian stage. It is named after the town of Givet in France. The oldest forests occurred during the late Givetian.[6]
| Givetian | |
|---|---|
| 387.7 ± 0.8 – 382.7 ± 1.6 Ma | |
| Chronology | |
Events of the Devonian Period -420 — – -415 — – -410 — – -405 — – -400 — – -395 — – -390 — – -385 — – -380 — – -375 — – -370 — – -365 — – -360 — – Key events of the Devonian Period. Axis scale: millions of years ago. | |
| Etymology | |
| Name formality | Formal |
| Usage information | |
| Celestial body | Earth |
| Regional usage | Global (ICS) |
| Time scale(s) used | ICS Time Scale |
| Definition | |
| Chronological unit | Age |
| Stratigraphic unit | Stage |
| Time span formality | Formal |
| Lower boundary definition | FAD of the Conodont Polygnathus hemiansatus |
| Lower boundary GSSP | Jebel Mech Irdane, Tafilalt, Morocco 31.2374°N 4.3541°W |
| GSSP ratified | 1994[4] |
| Upper boundary definition | FAD of the Conodont Ancyrodella rotundiloba |
| Upper boundary GSSP | Col du Puech de la Suque, Montagne Noire, France 43.5032°N 3.0868°E |
| GSSP ratified | 1986[5] |
Name and definition
The Givetian stage was proposed in 1879 by French geologist Jules Gosselet and was accepted for the higher stage of the Middle Devonian by the Subcommission on Devonian Stratigraphy in 1981.[7]
Givetian life
Actinistia
| Actinistians of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Gavinia | Upper Givetian | Bindaree Formation, Victoria, Australia | A basal actinistian | |
Tetrapodomorphs
| Tetrapodomorphs of the Givetian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Livoniana | upper Givetian | Gauja Formation, Latvia | A transitional form between fish and the earliest stegocephalian tetrapodomorphs. | |
| Platycephalichthys | upper Givetian | A derived eotetrapodiform fish very closely related to Elpistostegalia that includes tetrapods. | ||
| Tinirau | upper Givetian | Red Hill Formation, Eureka County, Nevada | A derived eotetrapodiform fish closely related to Elpistostegalia that includes tetrapods. | |
References
- Parry, S. F.; Noble, S. R.; Crowley, Q. G.; Wellman, C. H. (2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications". Journal of the Geological Society. London: Geological Society. 168 (4): 863–872. doi:10.1144/0016-76492010-043.
- Kaufmann, B.; Trapp, E.; Mezger, K. (2004). "The numerical age of the Upper Frasnian (Upper Devonian) Kellwasser horizons: A new U-Pb zircon date from Steinbruch Schmidt(Kellerwald, Germany)". The Journal of Geology. 112 (4): 495–501. Bibcode:2004JG....112..495K. doi:10.1086/421077.
- Algeo, T. J. (1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences. 353 (1365): 113–130. doi:10.1098/rstb.1998.0195.
- Walliser, O.; Bultynck, P.; Weddige, K.; Becker, R.; House, M. (September 1995). "Definition of the Eifelian-Givetian Stage boundary". Episodes. 18 (3): 107–115. doi:10.18814/epiiugs/1995/v18i3/002. Retrieved 19 December 2020.
- Klapper, Gilbert; Feist, Raimund; House, Michael (June 1987). "Decision on the Boundary Stratotype for the Middle/Upper Devonian Series Boundary". Episodes. 10 (2): 97–101. doi:10.18814/epiiugs/1987/v10i2/004. Retrieved 19 December 2020.
- Becker, R.T.; Gradstein, F.M.; Hammer, O. (2012). "Chapter 22 - The Devonian Period". In Gradstein, F.M.; Ogg, J.G.; Schmitz, M.D.; Ogg, G.M. (eds.). The Geologic Timescale 2012. Elsevier. p. 578. doi:10.1016/b978-0-444-59425-9.00022-6. ISBN 978-0-444-59425-9.
- Préat, Alain; Bultynck, Pierre (2006). "Givetian" (PDF). Geologica Belgica. 9 (1–2): 9–18. Retrieved 12 March 2013.
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