Valanginian

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Valanginian
139.8 ± 3.0 – 132.6 ± 2.0 Ma
Chronology

In the

Ma and 132.6 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceous and precedes the Hauterivian Stage of the Lower Cretaceous.[3]

Stratigraphic definitions

The Valanginian was first described and named by Édouard Desor in 1853. It is named after Valangin, a small town north of Neuchâtel in the Jura Mountains of Switzerland.

The base of the Valanginian is at the first appearance of

GSSP
) had in 2009 not yet been appointed.

The top of the Valanginian (the base of the Hauterivian) is at the first appearance of the

]

Subdivision

The Valanginian is often subdivided in Lower and Upper substages. The Upper substage begins at the first appearance of ammonite species Saynoceras verrucosum and the major marine transgression Va3.

In the Tethys domain, the Valanginian stage contains five ammonite biozones:

Flora

The oldest fossils that can definitely be attributed to the clade

Angiospermae (flowering plants) are dated to the Late Valanginian.[4]

References

Notes

  1. ^ International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. . Retrieved 24 December 2020.
  3. ^ See Gradstein et al. (2004) for a detailed geologic timescale
  4. PMID 30681148
    .

Literature

External links