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 ICS, as of 2017.[1]

In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago), but recent work in Argentina by De Lena and colleagues suggests this is not the case[citation needed]. The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian.[2]

Stratigraphic definitionEdit

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 has been under active consideration by the International Subcommission on Cretaceous Stratigraphy (ISCS) of IUGS. A range of contender GSSP localities has been studied in detail by the ISCS's Berriasian Working Group including localities as far apart as Mexico, Ukraine, Tunisia, Iraq and the Russian Far East. Several markers have been employed to refine correlations and to work towards defining 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 give greater precision in trying to identify the best position for a boundary. In June 2016, the Berriasian Working Group voted to adopt Calpionella alpina as the primary marker for the base of the Berriasian Stage. In May 2019, a GSSP for the Berriasian was selected by a vote of the Berriasian WG of the ISCS: it is the profile of Tré Maroua in the Vocontian Basin (Hautes Alpes, France)

In the western part of the ocean of Tethys, 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.

PalaeontologyEdit

Birds (avian theropods)Edit

Birds of the Berriasian
Taxa Presence Location Description Images

Crocodylomorphs (Non-Thalattosuchian)Edit

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

MammaliaEdit

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

†OrnithischiansEdit

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
England A dryosaurid

†PterosaursEdit

Pterosaurs of the Berriasian
Taxa Presence Location Description Images
Berriasian-Albian UK
Romania
Purbeck Limestone, Dorset, England

†SauropodsEdit

Sauropods of the Berriasian
Taxa Presence Location Description Images
South Africa

†ThalattosuchiaEdit

Thalattosuchians of the Berriasian
Taxa Presence Location Description Images
From Kimmeridgian to Valanginian
From Tithonian to Valanginian
From Kimmeridgian to Hauterivian Austria, England, Germany, Portugal and Switzerland

†Theropods (non-avian)Edit

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

Berriasian-Barremian

Sao Khua Formation, Thailand

ReferencesEdit

NotesEdit

  1. ^ Super User. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. ^ See Gradstein et al. (2012) for a detailed geological timescale
  3. ^ a b c d e f g h i Dating uncertain.
  4. ^ Only known from this stage.

LiteratureEdit

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

External linksEdit