Valanginian

Template:Cretaceous 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.

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:

• zone of Criosarasinella furcillata
• zone of Neocomites peregrinus
• zone of Saynoceras verrucosum
• zone of Busnardoites campylotoxus
• zone of Tirnovella pertransiens

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		France
Wyleyia

Crocodylomorphs

Crocodylomorphs of the Valanginian
Taxa	Presence	Location	Description	Images
Dakosaurus lapparenti				Dakosaurus Enaliosuchus
Enaliosuchus
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	First dinosaur ever found
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
Lonchodectes				Lonchodectes (left) Pterodaustro
Pterodaustro		Lagarcito Formation, San Luis Province, Argentina; Chile

†Sauropods

Sauropods of the Valanginian
Taxa	Presence	Location	Description	Images
Algoasaurus
Xenoposeidon

†Stegosaurs

Stegosaurs of the Valanginian
Taxa	Presence	Location	Description	Images
Craterosaurus				Wuerhosaurus
Paranthodon
Wuerhosaurus

†Theropods (non-avian)

Non-Avian Theropods of the Valanginian
Taxa	Presence	Location	Description	Images
"Ginnareemimus"
Nqwebasaurus
Phaedrolosaurus
Xinjiangovenator

References

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