Valanginian

Valanginian
Valanginian
~139.8 – ~132.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Chronology
←	K-Pg mass; extinction
	Subdivision of the Cretaceous according to the ICS, as of 2022.; Vertical 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	Not formally defined
Lower boundary definition candidates	FAD of the Calpionellid Calpionellites darderi
Lower boundary GSSP candidate section(s)	Montbrun-les-Bains, Drôme, France; Cañada Luenga, Betic Cordillera, Spain;
Upper boundary definition	FAD of the Ammonite genus Acanthodiscus
Upper boundary GSSP	La Charce, Drôme, France; 44°28′10″N 5°26′37″E / 44.4694°N 5.4437°E
Upper GSSP ratified	December 2019

In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 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 calpionellid species Calpionellites darderi in the stratigraphic column. A global reference section (a 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 ammonite genus Acanthodiscus.

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:

Palaeontology

†Ankylosaurs

Ankylosauria of the Valanginian
Taxa	Presence	Location	Description	Images
Hylaeosaurus				Hylaeosaurus

Birds (avian theropods)

Birds of the Valanginian
Taxa	Presence	Location	Description	Images
Gallornis^[4]		France
Wyleyia^[4]

Crocodylomorphs

Crocodylomorphs of the Valanginian
Taxa	Presence	Location	Description	Images
Geosaurus lapparenti^[5]				Enaliosuchus
Enaliosuchus^[5]
Machimosaurus

†Ornithopods

Ornithopoda of the Valanginian
Taxa	Presence	Location	Description	Images
Fulgurotherium		Australia	May be a chimera based on multiple species of ornithopods.	Iguanodon Lanzhousaurus Valdosaurus
Iguanodon		Europe
Kangnasaurus		Cape Province, South Africa	Generally considered nomen dubium, it classified as a genus similar to Dryosaurus, i.e. an iguanodont.
Lanzhousaurus		Lanzhou, Gansu, China	Notable for its "astonishingly huge teeth", among the largest for any herbivorous creature ever, which indicate it is an iguanodont. The mandible, longer than one meter, suggests very large size for the animal.
Valdosaurus		Isle of Wight, England; Niger, Africa	A dryosaurid

†Pterosaurs

Pterosaurs of the Valanginian
Taxa	Presence	Location	Description	Images
Amblydectes	Berriasian-Albian	UK		Pterodaustro
Lonchodraco
Pterodaustro		Lagarcito Formation, San Luis Province, Argentina; Chile
Serradraco		Sussex, England

†Sauropods

Sauropods of the Valanginian
Taxa	Presence	Location	Description	Images
Algoasaurus^[4]
Xenoposeidon^[4]

†Stegosaurs

Stegosaurs of the Valanginian
Taxa	Presence	Location	Description	Images
Craterosaurus^[4]				Wuerhosaurus
Paranthodon
Wuerhosaurus

†Theropods (non-avian)

Non-Avian Theropods of the Valanginian
Taxa	Presence	Location	Description	Images
Kinnareemimus				Nqwebasaurus
Nqwebasaurus^[4]
Phaedrolosaurus^[4]
Siamotyrannus	Berriasian-Barremian	Sao Khua Formation, Thailand
Valdoraptor	Late Valanginian, 136 Ma	Tunbridge Wells Sand Formation, England	A possible senior synonym of Thecocoelurus.
Xinjiangovenator

References

Notes

^ International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.
^ Mutterlose, Jörg; Rawson, Peter; Reboulet, Stéphane; Baudin, François; Bulot, Luc; Emmanuel, Laurent; Gardin, Silvia; Martinez, Mathieu; Renard, Maurice (September 2020). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hauterivian Stage (Lower Cretaceous), La Charce, southeast France". Episodes. doi:10.18814/epiiugs/2020/020072. Retrieved 24 December 2020.
^ See Gradstein et al. (2004) for a detailed geologic timescale
^ ^a ^b ^c ^d ^e ^f ^g Dating uncertain.
^ ^a ^b Only known from this stage.

Literature

Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; (2004): A Geologic Time Scale 2004, Cambridge University Press.

External links

GeoWhen Database - Valanginian
Mid-Cretaceous timescale and ühttp://stratigraphy.science.purdue.edu/charts/Timeslices/5_JurCret.pdf Jurassic-Cretaceous timescale], at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Lower Cretaceous, at the website of Norges Network of offshore records of geology and stratigraphy

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[1] International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.

[2] Mutterlose, Jörg; Rawson, Peter; Reboulet, Stéphane; Baudin, François; Bulot, Luc; Emmanuel, Laurent; Gardin, Silvia; Martinez, Mathieu; Renard, Maurice (September 2020). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hauterivian Stage (Lower Cretaceous), La Charce, southeast France". Episodes. doi:10.18814/epiiugs/2020/020072. Retrieved 24 December 2020.

[3] See Gradstein et al. (2004) for a detailed geologic timescale

[doubtful-4] ^ ^a ^b ^c ^d ^e ^f ^g Dating uncertain.

[endemic-5] Only known from this stage.

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