Frasnian
Template:Devonian The Frasnian is one of two faunal stages in the Late Devonian period. It lasted from 382.7 million years ago to 372.2 million years ago. It was preceded by the Givetian stage and followed by the Famennian stage.
Major reef-building was under way during the Frasnian stage, particularly in western Canada and Australia. On land, the first forests were taking shape. In North America, the Antler and Taconic orogenies peaked, which were contemporary with the Bretonic phase of the Variscan orogeny in Europe.
The Frasnian coincides with the second half of the "charcoal gap" in the fossil record, a time when atmospheric oxygen levels were below 13 percent, the minimum necessary to sustain wildfires.[1]
North American subdivisions of the Frasnian include
Name and definition
The Frasnian stage was proposed in 1879 by French geologist Jules Gosselet and was accepted for the lower stage of the Upper Devonian by the Subcommission on Devonian Stratigraphy in 1981.[2] It is named after the village of Frasnes-lez-Couvin in Belgium.[3]
Frasnian life
Fish
Cartilaginous fish
| Cartilaginous fish of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Stethacanthus | ||||
Placoderms
| Placoderms of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Bruntonichthys | Gogo Reef Formation, Australia | |||
| Groenlandaspis | ||||
| Camuropiscidae | Gogo Reef Formation, Australia | A family of mostly small, streamlined arthrodire placoderms. | ||
Sarcopterygians
Actinistia
| Actinistians of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Diplocercides | Bergisch-Gladbach, Germany[citation needed] | A basal actinistian | ||
| Miguashaia | Escuminac Formation, Quebec | A basal actinistian | ||
Dipnomorpha
| Dipnomorphans of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Gogodipterus | Gogo Formation, Australia | A lungfish in the extinct family Chirodipteridae. | ||
| Rhinodipterus | Gogo Formation, Australia | Might be the only known marine lungfish with air-breathing adaptations.[4] | ||
| Xeradipterus | Gogo Formation, Australia | A lungfish in the extinct family Holodontidae. | ||
Tetrapodomorphs
| Tetrapodomorphs of the Frasnian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Gogonasus | Gogo Formation, Australia |     | ||
| Elginerpeton | Scat Craig, Scotland | |||
| Elpistostege | Escuminac Formation, Quebec, Canada | |||
| Metaxygnathus | New South Wales, Australia | |||
| Obruchevichthys | Ogre Formation, Latvia | |||
| Panderichthys | Early Frasnian | Mikhailovskii Mine, Zheleznogorsk, Russia | ||
| Tiktaalik | Fram Formation, Nunavut, Canada | |||
References
- ^ McGhee, George R. Jr. (12 November 2013). When the Invasion of Land Failed: The Legacy of the Devonian Extinctions. Columbia University Press. pp. 110–11. ISBN 978-0-231-16057-5. Retrieved 21 April 2015.
- ^ Coen-Aubert, Marie; Boulvain, Frédéric (2006). "Frasnian". Geologica Belgica. 9 (1–2): 19–25. Retrieved 10 March 2013.
- ^ "Frasnian mudmounds from Belgium". University of Liège. Retrieved 2011-02-25.
- ^ Clement, A. & Long, J.A. 2010. Air-breathing adaptation in a marine Devonian lungfish. Biology Letters 6: 509–512.
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