Jump to content

Wordian

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Nemo bis (talk | contribs) at 07:56, 25 April 2021 (remove URL redundant with identifier in autolinked citation). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Wordian
268.8 ± 0.5 – 265.1 ± 0.4 Ma
↓
Chronology
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the Conodont Jinogondolella aserrata
Lower boundary GSSPGuadalupe Pass, Guadalupe Mountains, Texas, USA
31°51′57″N 104°49′58″W / 31.8658°N 104.8328°W / 31.8658; -104.8328
Lower GSSP ratified2001[2]
Upper boundary definitionFAD of the Conodont Jinogondolella postserrata
Upper boundary GSSPNipple Hill, Guadalupe Mountains, Texas, USA
31°54′33″N 104°47′21″W / 31.9091°N 104.7892°W / 31.9091; -104.7892
Upper GSSP ratified2001[2]

In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian epoch or series. The Wordian lasted between 266.9 and 264.28 million years ago (Ma). It was preceded by the Roadian and followed by the Capitanian.[3]

Stratigraphy

The Wordian stage was introduced into scientific literature by Johan August Udden in 1916 and was named after the Word Formation of the North American Permian Basin. The Wordian was first used as a stratigraphic subdivision of the Guadalupian in 1961,[4] when both names were still only used regionally in the southern US. The stage was added to the internationally used ISC timescale in 2001.[5]

The base of the Wordian stage is defined as the place in the stratigraphic record where fossils of conodont species Jinogondolella aserrata first appear. The global reference profile for this stratigraphic boundary is located at Getaway Ledge in the Guadalupe Mountains of Texas.

The top of the Wordian (the base of the Capitanian stage) is defined as the place in the stratigraphic record where the conodont species Jinogondolella postserrata first appears.

The Wordian stage was part of the time in which the Zechstein was deposited in Europe.

Biostratigraphy

The Wordian spans the entire conodont biozone of Jinogondolella aserrata. It contains two fusulinid biozones:

  • Zone of Afganella tereshkovae
  • Zone of Neoschwagerina tenuis

Biodiversity

Olson’s Extinction, a worldwide loss of terrestrial vertebrate life occurred during the Early Guadalupian (Roadian, Wordian).[6]

Wordian life

Chondrichthyans

Chondrichthyes of the Wordian
Taxa Presence Location Description Images
Carboniferous to Guadalupian Russia, United States A ctenacanthiform elasmobranch
Glikmanius

Actinopterygians

Actinopterygii of the Wordian
Taxa Presence Location Description Images
Carboniferous to Lopingian Russia A non-neopterygian
Platysomus
Permian Russia A non-neopterygian

Amphibia

Amphibia of the Wordian
Taxa Presence Location Description Images
Wordian - Wuchiapingian Brazil A stereospondyl temnospondyl amphibian, possibly a rhinesuchid.
Australerpeton
Kamacops acervalis
Tryphosuchus
Zygosaurus
268.0–265.0 Ma Russia A genus of dissorophoid temnospondyl amphibian of the family Dissorophidae.
268.0–265.0 Ma Perm Krai, Russia A genus of dissorophoid temnospondyl amphibian of the family Dissorophidae. It was very closely related to the earlier Cacops and its contemporary Zygosaurus..
268.0–265.0 Ma Isheevo Assemblage Zone and Amanakskaya Formation, European Russia An archegosaurid temnospondyl amphibian.
268.0–265.0 Ma Russia A genus of dissorophoid temnospondyl amphibian of the family Dissorophidae. It was very closely related to its contemporary Kamacops and the earlier Cacops .

Diapsids

Diapsida of the Wordian
Taxa Presence Location Description Images
Guadalupian Russia A neodiapsid
Lanthanolania

Parareptilia

Parareptiles of the Wordian
Taxa Presence Location Description Images
late Roadian to latest Wordian Russia A procolophonomorph parareptile.

Synapsids (non-therapsid)

Synapsida of the Wordian
Taxa Presence Location Description Images
Guadalupian Russia A caseasaurian
Ennatosaurus

Therapsids

Therapsida of the Wordian
Taxa Presence Location Description Images
Guadalupian Perm Krai, Russia A biarmosuchian therapsid
Biarmosuchus
Eodicynodon
Estemmenosuchus
Parabradysaurus
Guadalupian South Africa A dicynodont therapsid
Guadalupian Perm Krai, Russia A biarmosuchian therapsid
Guadalupian Russia A dinocephalian therapsid
Guadalupian Russia A biarmosuchian therapsid
Guadalupian Russia A biarmosuchian therapsid
Guadalupian Russia A dinocephalian therapsid
Guadalupian South Africa An anomodont therapsid
Guadalupian Russia A phthinosuchid therapsid
Guadalupian South Africa A dinocephalian therapsid

References

  1. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  2. ^ a b "GSSP for Roadian Stage". International Commission on Stratigraphy. International Commission on Stratigraphy. Retrieved 13 December 2020.
  3. ^ Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press
  4. ^ Glenister, B.F. & Furnish, W.M.; 1961: The Permian ammonoids of Australia, Journal of Paleontology 35(4), pp 673–736.
  5. ^ Glenister, B.F.; Wardlaw, B.R.; Lambert, L.L.; Spinosa, C.; Bowring, S.A.; Erwin, D.H.; Menning, M. & Wilde, G.L.; 1999: Proposal of Guadalupian and Component Roadian, Wordian and Capitanian Stages as International Standards for the Middle Permian Series, Permophiles 34: pp 3–11.
  6. ^ Sahney, S. & Benton, M.J. (2008). "Recovery from the most profound mass extinction of all time" (PDF). Proceedings of the Royal Society B: Biological Sciences. 275 (1636): 759–65. doi:10.1098/rspb.2007.1370. PMC 2596898. PMID 18198148.

Literature

Retrieved from "https://en.wikipedia.org/w/index.php?title=Wordian&oldid=1019762307"