Rearuh

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.^[2]

Stratigraphic definitions

Barremian sedimentary rock layers, France

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.

Regional equivalents

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.^[2]

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
Cedrorestes		Utah, USA
Fukuisaurus		Japan
Hypsilophodon		England
Iguanodon		Europe
Jeholosaurus		China
Jinzhousaurus		China
Mantellisaurus		Europe
Planicoxa		Poison Stirp Sandstone Member, Cedar Mountain Formation, Utah, USA
Proplanicoxa		Wessex Formation, Isle of Wight
Psittacosaurus		China, Mongolia, Russia, possibly Thailand
Siluosaurus		Gansu, China
Stenopelix		Obernkirchen Sandstein Formation, Germany
Valdosaurus		Europe

†Sauropoda

Sauropods of the Barremian
Taxa	Presence	Location	Description	Images
Amargasaurus		Neuquén, Argentina		Amargasaurus
Amargatitanis		Neuquén, Argentina
Aragosaurus		Aragón, Spain
Cedarosaurus		Utah, USA
Chondrosteosaurus		Wessex Formation, Isle of Wight, England
Eucamerotus		Isle of Wight, England
Histriasaurus		Croatia
Ornithopsis
Oplosaurus		Isle of Wight, England
Phuwiangosaurus		Sao Khua Formation

Theropoda

Theropods of the Barremian
Taxa	Presence	Location	Description	Images
Aristosuchus		Wessex Formation, Isle of Wight England		Baryonyx Caudipteryx Changchengornis Falcarius Longipteryx Harpymimus Incisivosaurus Microraptor Neovenator Shenzhousaurus Siamosaurus Sinornithosaurus Utahraptor
Baryonyx		England, Spain, Portugal
Calamosaurus		Isle of Wight, England
Caudipteryx		Liaoning, China
Changchengornis		Liaoning, China
Concavenator		Spain	A sail-backed carcharodontosaurid
Concornis		Cuenca, Spain
Eoalulavis		Calizas de La Huérgina Formation Spain
Falcarius		Utah, USA	A therizinosaur that is one of the few North American varieties of its clade.
Fukuiraptor		Japan
Harpymimus		Gobi Desert, Mongolia
Huaxiagnathus		Liaoning, China
Iberomesornis		Cuenca, Spain
Incisivosaurus		Liaoning, China
Longipteryx		Liaoning, China
Microraptor		Liaoning, China
"Nanshiungosaurus" bohlini
Neovenator		Isle of Wight, England
Pelecanimimus		Cuenca, Spain
Prodeinodon		China, Mongolia
Sapeornis		Liaoning, China
Shenzhousaurus		Liaoning, China
Siamosaurus		Sao Khua Formation, Thailand
Sinornithosaurus		Liaoning, China
Sinovenator		Liaoning, China
Utahraptor		Utah, USA
Yaverlandia		Isle of Wight, England
Yixianosaurus		Liaoning, China

†Thyreophora

Thyreophora of the Barremian
Taxa	Presence	Location	Description	Images
Craterosaurus		England		Fossil of Gastonia Polacanthus
Gastonia		Utah, USA
Liaoningosaurus		Liaoning, China
Polacanthus		England
Sauroplites		Gansu, China

Mammals

Mammals of the Barremian
Taxa	Presence	Location	Description	Images
Crusafontia		EL Castellar Formation and La Huéguina Formation, Spain		Skeleton of the primitive mammal Eomaia Repenomamus
Eobaatar	several species from Hauterivian to Albian	Spain, Mongolia
Eomaia
Jeholodens		Yixian Formation
Repenomamus
Sinobaatar		Yixian Formation
Zhangheotherium		Yixian Formation

†Plesiosaurians

†Pterosaurs

Liaoningopterus

• 
  Azhdarchoidea incertae sedis: Chaoyangopterus,^[5]Jidapterus
  


• 
  Ctenochasmatidae: Beipiaopterus, Liaoxipterus
  


• 
  Istiodactylidae: Hongshanopterus,Istiodactylus,Longchengpterus, Nurhachius
  


• 
  Ornithocheiridae: Amblydectes, Haopterus, Liaoningopterus
  


• 
  Ornithocheiroidea incertae sedis: Boreopterus
  


• 
  Pterodactyloidea incertae sedis: Feilongus
  


• 
  Tapejaridae: Huaxiapterus, Sinopterus
  

References

Notes

Literature

• 
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  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. (in 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