| System (period) | Series | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Triassic | Lower | Induan | 251.902±0.024 | |
| Permian | Lopingian | Changhsingian |  254.14±0.07
| |
| Wuchiapingian | 259.51±0.21
| |||
| Guadalupian | Capitanian | 264.28±0.16
| ||
| Wordian | 266.9±0.4
| |||
| Roadian | 273.01±0.14
| |||
| Cisuralian | Kungurian | 283.5±0.6 | ||
| Artinskian | 290.1±0.26
| |||
| Sakmarian | 293.52±0.17
| |||
| Asselian | 298.9±0.15
| |||
| Carb. | Pen. | Upper | Gzhelian | older |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
The Wordian is a second stage in the Guadalupian, the second series of the Permian system. Its geochronologic equivalent is the Wordian age of the Guadalupian epoch of the Permian period. It lasted from approximately 266.9 Ma to around 264.28 Ma (million years ago). It was preceded by the Roadian and followed by the Capitanian. It was named after the Word Formation in USA.[2] A mass extinction called Olson's extinction occured during the Wordian, and the Stage before it, the Roadian.
Definition[]
The GSSP of the Givetian stage was ratified in 2001. The lower boundary is fixed in the Getaway Ledge outcrop Section of the Cherry Canyon Formation in Guadalupe Pass, Texas, USA, and related to the first appearance of the conodont species Jinogondolella aserrata.[3]
Climate[]
The Wordian and the rest of the Guadalupian had torrid summers and frigid winters, with constant monsoons.
Wordian life[]
Conodonts, a group of jawless vertebrae, were dominant during the Wordian age, especially Jinogondellola asserata and Jinogondellola postserrta. Therapsids were the dominant life forms during the Guadalupian. Therapsida is divided into four groups: Dinocephalia or the large bodied therapsids, the anomodonts (herbivores), biarmosuchians (carnivores), and the theriodonts (mostly carnivores but some were herbivores). All these groups evolved the sphenacodonts, a group of pelycosaurs. Titanophoneus was at the top of the food chain during the Wordian, and the whole Guadalupian.
The guadalupian
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ https://en.wikipedia.org/wiki/Wordian
- ↑ "GSSP Table - Paleozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=77.