World Library  
My Account |  Register |  Help  
  
Flag as Inappropriate
Email this Article
 

Berriasian

System/
Period 		Series/
Epoch 		Stage/
Age 		Age (Ma)
Paleogene Paleocene Danian younger
Cretaceous Upper/
Late 		Maastrichtian 66.0–72.1
Campanian 72.1–83.6
Santonian 83.6–86.3
Coniacian 86.3–89.8
Turonian 89.8–93.9
Cenomanian 93.9–100.5
Lower/
Early 		Albian 100.5–~113.0
Aptian ~113.0–~125.0
Barremian ~125.0–~129.4
Hauterivian ~129.4–~132.9
Valanginian ~132.9–~139.8
Berriasian ~139.8–~145.0
Jurassic Upper/
Late 		Tithonian older
Subdivision of the Cretaceous system
according to the IUGS, as of July 2012.

In the geological timescale, the Berriasian is an age or stage of the Early Cretaceous. It is the oldest, or lowest, subdivision in the entire Cretaceous. It spanned the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian.[1]

Contents

  • Stratigraphic definition 1
  • Palaeontology 2
    • Birds (avian theropods) 2.1
    • Crocodylomorphs (Non-Thalattosuchian) 2.2
    • Mammalia 2.3
    • †Ornithischians 2.4
    • †Pterosaurs 2.5
    • †Sauropods 2.6
    • †Thalattosuchia 2.7
    • †Theropods (non-avian) 2.8
  • References 3
    • Notes 3.1
    • Literature 3.2
  • External links 4

Stratigraphic definition

The Berriasian Stage was introduced in scientific literature by Henri Coquand in 1869. It is named after the village of Berrias in the Ardèche department of France. The largely non-marine English Purbeck Formation is in part of Berriasian age. In fact, the first rocks to be described of this age were the beds of the English Purbeck Formation, named as the Purbeckian by Alexandre Brongniart in 1829 following description by Henry De la Beche, William Buckland, Thomas Webster and William Henry Fitton.

The base of the Berriasian, which is also the base of the Cretaceous system, has traditionally been placed at the first appearance of fossils of the ammonite species Berriasella jacobi. But this is a species that has a stratigraphically problematic and geographically limited distribution. A global reference profile (a GSSP) for the Berriasian is under active consideration by the International Subcommission on Cretaceous Stratigraphy (ISCS) of IUGS. A range of contender GSSP localities currently being studied in detail by the ISCS's Berriasian Working Group include localities as far apart as Mexico, Ukraine, Tunisia, Iraq and the Russian Far East. Several markers are being employed to refine correlations and to work towards definition of a base for the Berriasian Stage. These include calcareous nannofossils, such as Nannoconus, calpionellids, ammonites, palynological data and magnetostratigraphy, notably magnetozone M19n. The calibration of these markers, especially Nannoconus steinmannii minor, N. kamptneri minor, and Calpionella alpina, within precisely fixed magnetozones gives greater precision in trying to identify the best position for a boundary.

In the Tethys Ocean, the Berriasian consists of four ammonite biozones, from top to bottom (latest to earliest):

The top of the Berriasian stage is defined by the base of the Valanginian, which is fixed at the first appearance of calpionellid species Calpionellites darderi. This is just a little below the first appearance of the ammonite species Thurmanniceras pertransiens.

Palaeontology

Birds (avian theropods)

Birds of the Berriasian
Taxa Presence Location Description Images

Crocodylomorphs (Non-Thalattosuchian)

Non-Thalattosuchian Crocodylomorphs of the Berriasian
Taxa Presence Location Description Images

Mammalia

Mammals of the Berriasian
Taxa Presence Location Description Images
Durlston Bay, Dorset, England
Durlston Bay, Dorset, England; Spain
Portugal
Durlston Bay, Dorset, England
Portugal

†Ornithischians

Ornithischians of the Berriasian
Taxa Presence Location Description Images
Swanage, England A bipedal herbivore, it was around 0.6 meters (2 ft) long. Unlike most ornithischians, Echinodon had one or two caniniform teeth in each maxilla.
Kirkwood Formation, Cape Province, South Africa A 4 meters long, 1.8 meters high stegosaurid with a skull similar to Kentrosaurus
Isle of Wight, England; Niger, Africa A dryosaurid

†Pterosaurs

Pterosaurs of the Berriasian
Taxa Presence Location Description Images
Purbeck Limestone, Dorset, England

†Sauropods

Sauropods of the Berriasian
Taxa Presence Location Description Images

†Thalattosuchia

†Thalattosuchians of the Berriasian
Taxa Presence Location Description Images
From Kimmeridgian to Valanginian Austria, England, Germany, Portugal and Switzerland
Attested since Toarcian England, France, Germany, Switzerland and Morocco

†Theropods (non-avian)

†Non-avian theropods of the Berriasian
Taxa Presence Location Description Images

References

Notes

  1. ^ See Gradstein et al. (2004) for a detailed geological timescale
  2. ^ a b Only known from this stage.
  3. ^ a b c d e f g h i Dating uncertain.

Literature

External links

  • GeoWhen Database - Berriasian
  • 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
 
 
kya = thousands years ago. Mya = millions years ago. * Not officially recognized by the I.C.S.
Source: (2015/01). International Commission on Stratigraphy. Retrieved 13 July 2015. Divisions of Geologic Time—Major Chronostratigraphic and Geochronologic Units USGS Retrieved 10 March 2013.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.