Barremian

The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch (or Lower Cretaceous series). It is preceded by the Hauterivian and followed by the Aptian stage.^[1]

The Barremian falls in the Gallic epoch, a subdivision of the Cretaceous that is no longer used by the ICS. It overlaps the lower part of the Urgonian stage, which is sometimes used in western European stratigraphy. In North America, the late Coahulian and the early Comanchean correspond to the Barremian. In New Zealand, it falls within the Mokoiwian, and in Japan it corresponds to the late Aritan.^[1]

Stratigraphic definitions

The original type locality for the Barremian stage is in the vicinity of the village of Barrême, Alpes-de-Haute-Provence, France. Henri Coquand defined the stage and named it in 1873.

The base of the Barremian is determined by the first appearance of the ammonites Spitidiscus hugii and Spitidiscus vandeckii. The end of the Barremian is determined by the geomagnetic reversal at the start of the M0r chronozone, which is biologically near the first appearance of the ammonite Paradeshayesites oglanlensis.

Subdivision

The Barremian is often subdivided into two substages or subages, Lower/Early and Upper/Late Barremian.

In the Tethys domain, the Barremian stage contains eleven ammonite biozones:

• zone of Pseudocrioceras waagenoides
• zone of Colchidites sarasini
• zone of Imerites giraudi
• zone of Hemihoplites feraudianus
• zone of Gerhardtia sertousi
• zone of Ancyloceras vandenheckii
• zone of Coronites darsi
• zone of Kotetishvilia compressissima
• zone of Nicklesia pulchella
• zone of Nicklesia nicklesi
• zone of Spitidiscus hugii

Palaeontology

Much knowledge about the Barremian fauna—especially regarding birds, mammals and pterosaurs—derived from the famous Yixian Formation of China, part of which dates from this stage.

Cephalopods

†Ammonoidea

Annuloceras

Neocoleoids

†Belemnites

Belemnites of the Barremian
Taxa	Presence	Location	Description	Images
Curtohibolites				Belemnites
Neohibolites
Oxyteuthis

Nautiloidea

Nautiloids of the Barremian
Taxa	Presence	Location	Description	Images
Eucymatoceras				An illustration of a variety of fossil nautiloids.
Palelialia
Pseudaturoidea

Chondrichthyes

• Hexanchidae: Notidanodon lanceolatus, Notorynchus aptiensis

Squamata

• Iguania: Xianglong

Dinosaurs (including birds)

†Cerapoda

Cerapoda of the Barremian
Taxa	Presence	Location	Description	Images
Jinzhousaurus		China
Ponerosteus		Czech Republic
Fukuisaurus		Japan
Hypsilophodon		England, Spain, Portugal
Jeholosaurus		China
Cedrorestes		Utah, USA
Valdosaurus		Europe, Africa
Dakotadon		North America
Dollodon		Belgium, Germany, England
Iguanodon		Europe
Osmakasaurus		South Dakota, USA
Siluosaurus		Gansu, China
Hongshanosaurus		Liaoning, China
Psittacosaurus		China, Mongolia, Russia, possibly Thailand

†Other Cerapods

†Sauropoda

Theropoda

Theropods of the Barremian
Taxa	Presence	Location	Description	Images
Fukuiraptor		Japan
Concavenator		Spain	A sail-backed carcharodontosaurid
Longipteryx		Liaoning, China
"Proornis"		North Korea
Neovenator		Isle of Wight, England
Caudipteryx		Liaoning, China
Huaxiagnathus		Liaoning, China
Changchengornis		Liaoning, China
Microraptor		Liaoning, China
Sinornithosaurus		Liaoning, China
Utahraptor		Utah, USA
Concornis		Cuenca, Spain
Iberomesornis		Cuenca, Spain
Harpymimus		Gobi Desert, Mongolia
Yixianosaurus		Liaoning, China
Afrovenator		Niger, Africa
Sapeornis		Liaoning, China
Shenzhousaurus		Liaoning, China
Pelecanimimus		Cuenca, Spain
Incisivosaurus		Liaoning, China
Baryonyx		England, Spain, Portugal
Chilantaisaurus		China
Calamosaurus		Isle of Wight, England
Prodeinodon		China, Mongolia
Yaverlandia		Isle of Wight, England
Sinovenator		Liaoning, China
Falcarius		Utah, USA	A therizinosaur that is one of the few North American varieties of its clade.

†Thyreophora

Mammals

Mammals of the Barremian
Taxa	Presence	Location	Description	Images
Eobaatar	several species from Hauterivian to Albian	Spain, Mongolia		Skeleton of the primitive mammal Eomaia Repenomamus
Eomaia
Repenomamus

†Pterosaurs

Liaoningopterus

• Azhdarchoidea incertae sedis: Chaoyangopterus,^[4] Jidapterus
• Ctenochasmatidae: Beipiaopterus, Liaoxipterus
• Istiodactylidae: Hongshanopterus,Istiodactylus,Longchengpterus, Nurhachius
• Ornithocheiridae: Haopterus, Liaoningopterus
• Ornithocheiroidea incertae sedis: Boreopterus
• Pterodactyloidea incertae sedis: Feilongus
• Tapejaridae: Huaxiapterus, Sinopterus

References

Notes

Literature

• Cossmann, M. & Pelat, E. (1907): Le Barrémien supérieur à faciès Urgonien de Brouzet-lès-Alais (Gard). Mémoires de la Société Géologique de France, Paléontologie 15(37): 5-42. (French)
• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; (2004): A Geologic Time Scale 2004, Cambridge University Press.
• Guzhikov, A.Yu. & Baraboshkin, E.J. (2006): Assessment of diachronism of biostratigraphic boundaries by magnetochronological calibration of zonal scales for the Lower Cretaceous of the Tethyan and Boreal belts. Doklady Earth Sciences 409(6): 843-846. doi:10.1134/S1028334X06060018

External links

• GeoWhen Database - Barremian
• Mid-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