Wordian

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 268.8 and 265.1 million years ago (Ma). It was preceded by the Roadian and followed by the Capitanian.[2]

Wordian
268.8 ± 0.5 – 265.1 ± 0.4 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Chronology
Key events in the Permian -300 — – -295 — – -290 — – -285 — – -280 — – -275 — – -270 — – -265 — – -260 — – -255 — – -250 — P a l e o z o i c M Z C P e r m i a n T P L P C i s u r a l i a n G u a d a l u p. L o p i n. E T Gzhelian Asselian Sakmarian Artinskian Kungurian Roadian Wordian Capitanian Wuchiapingian Changhsingian Induan         ← Permian-Triassic mass extinction event ← end-Capitanian extinction event ← Olson's Extinction An approximate timescale of key Permian events. 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 Jinogondolella aserrata
Lower boundary GSSP	Guadalupe Pass, Guadalupe Mountains, Texas, USA 31.8658°N 104.8328°W
GSSP ratified	2001[1]
Upper boundary definition	FAD of the Conodont Jinogondolella postserrata
Upper boundary GSSP	Nipple Hill, Guadalupe Mountains, Texas, USA 31.9091°N 104.7892°W
GSSP ratified	2001[1]

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,[3] when both names were still only used regionally in the southern US. The stage was added to the internationally used ISC timescale in 2001.[4]

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).[5]

Wordian life

Actinopterygians

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

Amphibia

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

Diapsids

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

Parareptilia

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

Synapsids (non-therapsid)

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

Therapsids

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

References

1. "GSSP for Roadian Stage". International Commission on Stratigraphy. International Commission on Stratigraphy. Retrieved 13 December 2020.
2. Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press
3. Glenister, B.F. & Furnish, W.M.; 1961: The Permian ammonoids of Australia, Journal of Paleontology 35(4), pp 673–736.
4. 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.
5. 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.

External links

• GeoWhen Database - Wordian
• Upper Paleozoic stratigraphic chart at the website of the subcommission for stratigraphic information of the ICS