Pliensbachian

System/
Period		 Series/
Epoch		 Stage/
Age		 Age (Ma)
Cretaceous Lower/
Early		 Berriasian younger
Jurassic Upper/
Late		 Tithonian ~145.0 152.1
Kimmeridgian 152.1 157.3
Oxfordian 157.3 163.5
Middle Callovian 163.5 166.1
Bathonian 166.1 168.3
Bajocian 168.3 170.3
Aalenian 170.3 174.1
Lower/
Early		 Toarcian 174.1 182.7
Pliensbachian 182.7 190.8
Sinemurian 190.8 199.3
Hettangian 199.3 201.3
Triassic Upper/
Late		 Rhaetian older
Subdivision of the Jurassic system
according to the ICS, as of 2017.[1]

The Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the Early or Lower Jurassic epoch or series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago).[2] The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.[3]

Example of a Pliensbachian ecosystem, the Drzewica Formation of Szydłowiec in Poland, characterised by a very damp ecosystem, populated by dinosaur megafauna

The Pliensbachian ended with the extinction event called the Toarcian turnover. During the Pliensbachian, the middle part of the Lias was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of North America.

Stratigraphic definitions

The Pliensbachian takes its name from the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, some 30 km east of Stuttgart in Germany. The name was introduced into scientific literature by German palaeontologist Albert Oppel in 1858.

The base of the Pliensbachian is at the first appearances of the ammonite species Bifericeras donovani and genera Apoderoceras and Gleviceras. The Wine Haven profile near Robin Hood's Bay (Yorkshire, England) has been appointed as global reference profile for the base (GSSP).[4]

The top of the Pliensbachian (the base of the Toarcian stage) is at the first appearance of ammonite genus Eodactylites.

Biostratigraphy

Pleuroceras spinatum Museum of Toulouse

The Pliensbachian contains five ammonite biozones in the boreal domain:

In the Tethys domain, the Pliensbachian contains six biozones:

Palaeontology

Amphibians

Amphibians of the Pliensbachian
Taxa Presence Location Description Images
Pliensbachian-Toarcian Evergreen Formation, Australia

Ichthyosaurs

Ichthyosaurs of the Pliensbachian
Taxa Presence Location Description Images
Europe
Hettangian to Toarcian All over Europe An ichthyosaur that exceeded 12 metres (39 ft) in length

†Ornithischians

Ornithischians of the Pliensbachian
Taxa Presence Location Description Images
Lower Lufeng Formation, Yunnan, China A dubious basal thyreophoran.

Theropods

Theropods of the Pliensbachian
Taxa Presence Location Description Images
Hanson Formation, Antarctica A dilophosaurid. About 7 meters (23 feet) long with a high, narrow skull and a peculiar nasal crest just over the eyes.
Sinemurian to Pliensbachian Arizona, USA Measured around six meters (20 ft) long and may have weighed half a ton. The most distinctive characteristic of Dilophosaurus is the pair of rounded crests on its skull, possibly used for display.

References

Notes

  1. ↑ http://www.stratigraphy.org/index.php/ics-chart-timescale
  2. ↑ Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. pp. 44–45. ISBN 978-0-7566-9910-9.
  3. ↑ See Gradstein et al. (2004) for a detailed geologic timescale
  4. ↑ Meister et al. (2006)

Literature

  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
  • Howart, M.K.; 2002: The Lower Lias of Robin Hood's Bay, Yorkshire, and the work of Leslie Bairstow, Bulletin of the Natural History Museum. Geology Series 58, p. 81–152, Cambridge University Press, The Natural History Museum, (abstract)
  • Meister, C.; Aberhan, M.; Blau, J.; Dommergues, J.-L.; Feist-Burkhardt, S.; Hailwood, E.A.; Hart, M.; Hesselbo, S.P.; Hounslow, M.W.; Hylton, M.; Morton, N.; Page, K & Price, G.D.; 2006: The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK, Episodes 29(2), pp. 93–106.
  • Oppel, C.A.; 1856-1858: Die Juraformation Englands, Frankreichs und des südwestlichen Deutschlands: nach ihren einzelnen Gliedern engetheilt und verglichen, 857 pp., Ebner & Seubert, Stuttgart. (in German)
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