The
Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the
Early or Lower JurassicThe Early Jurassic epoch The Early Jurassic epoch The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series is the earliest of three epochs of the Jurassic period...
epoch or
seriesSeries are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...
and spans the time between 189.6 ± 1.5
MaAnnum is a form of the Latin noun annus meaning year, from which are derived words such as annual and annuity. Annum is the accusative singular of the 2nd declension masculine noun annus , anni...
and 183 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the
SinemurianIn the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...
and followed by the
ToarcianThe Toarcian is, in the ICS' geologic timescale, an age or stage in the Early or Lower Jurassic. It spans the time between 183.0 Ma and 175.6 Ma...
.
The Pliensbachian ended with the
extinction eventAn extinction event is a sharp decrease in the number of species in a relatively short period of time. Mass extinctions affect most major taxonomic groups present at the time — birds, mammals, reptiles, amphibians, fish, invertebrates and other simpler life forms...
called the
Toarcian turnoverThe term Toarcian turnover, alternatively the Toarcian extinction, the Pliensbachian-Toarcian extinction, or the Early Jurassic extinction, refers to the wave of extinctions that marked the end of the Pliensbachian stage and the start of the Toarcian stage of the Early Jurassic period, c...
. During the Pliensbachian, the middle part of the
LiasLias may refer to:* Lias , a troll drummer in the book Soul Music by Terry Pratchett* Lias Group, a stratigraphic group found in large parts of Europe, formed during the Early Jurassic epoch* Lias, Gers, a commune of the Gers département, in France...
was deposited in Europe.
The
Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the
Early or Lower JurassicThe Early Jurassic epoch The Early Jurassic epoch The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series is the earliest of three epochs of the Jurassic period...
epoch or
seriesSeries are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...
and spans the time between 189.6 ± 1.5
MaAnnum is a form of the Latin noun annus meaning year, from which are derived words such as annual and annuity. Annum is the accusative singular of the 2nd declension masculine noun annus , anni...
and 183 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the
SinemurianIn the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...
and followed by the
ToarcianThe Toarcian is, in the ICS' geologic timescale, an age or stage in the Early or Lower Jurassic. It spans the time between 183.0 Ma and 175.6 Ma...
.
The Pliensbachian ended with the
extinction eventAn extinction event is a sharp decrease in the number of species in a relatively short period of time. Mass extinctions affect most major taxonomic groups present at the time — birds, mammals, reptiles, amphibians, fish, invertebrates and other simpler life forms...
called the
Toarcian turnoverThe term Toarcian turnover, alternatively the Toarcian extinction, the Pliensbachian-Toarcian extinction, or the Early Jurassic extinction, refers to the wave of extinctions that marked the end of the Pliensbachian stage and the start of the Toarcian stage of the Early Jurassic period, c...
. During the Pliensbachian, the middle part of the
LiasLias may refer to:* Lias , a troll drummer in the book Soul Music by Terry Pratchett* Lias Group, a stratigraphic group found in large parts of Europe, formed during the Early Jurassic epoch* Lias, Gers, a commune of the Gers département, in France...
was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
.
Stratigraphic definitions
The Pliensbachian takes its name from the hamlet of Pliensbach in the community of
Zell unter AichelbergZell unter Aichelberg is a town in the district of Göppingen in Baden-Württemberg in southern Germany....
in the
Swabian AlbThe Swabian Alb or Swabian Jura is a low mountain range in Baden-Württemberg, Germany, extending 220 km from southwest to northeast and 40 to 70 km in width. It is named after the region of Swabia....
, some 30 km east of
StuttgartStuttgart is the capital of the state of Baden-Württemberg in southern Germany. The sixth-largest city in Germany, Stuttgart has a population of 600,038 while the metropolitan area has a population of 5.3 million ....
in
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
. The name was introduced into scientific literature by German palaeontologist
Albert OppelCarl Albert Oppel was a German paleontologist.-History:He was born at Hohenheim in Wurttemberg, on December 19th, 1831. He first went to the University of Tubingen, where he graduated with a Ph.D. in 1853. The results of his work was published in Die Juraformation Englands, Frankreichs and des...
in 1858.
The base of the Pliensbachian is at the first appearances of the ammonite species
Bifericeras donovaniBifericeras is an extinct genus of cephalopod belonging to the Ammonite subclass....
and
generaIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
ApoderocerasApoderoceras is an extinct genus of cephalopod belonging to the Ammonite subclass....
and
GlevicerasGleviceras is an extinct genus of cephalopod belonging to the Ammonite subclass....
. The Wine Haven profile near
Robin Hood's BayRobin Hood’s Bay is a small fishing town or village located five miles south of Whitby on the coast of North Yorkshire, England. Bay Town, as it is known to the locals, is in the ancient parish of Fylingdales and in the wapentake of Whitby Strand....
(
YorkshireYorkshire is a historic county of northern England and the largest in the British Isles. Because of its great size, functions were increasingly undertaken over time by its subdivisions, which have been subject to periodic reform. Throughout these changes, Yorkshire has continued to be recognised as...
,
EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
) has been appointed as global reference profile for the base (GSSP).
The top of the Pliensbachian (the base of the Toarcian stage) is at the first appearance of ammonite genus
Eodactylites.
Biostratigraphy
The Pliensbachian contains five ammonite
biozoneBiostratigraphic units or Biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa....
s in the boreal domain:
- zone of Pleuroceras spinatum
Pleuroceras is a genus of fungi in the family Gnomoniaceae.-External links:* at Index Fungorum...
- zone of Amaltheus margaritatus
Amaltheus is an extinct genus of cephalopod belonging to the Ammonite subclass....
- zone of Prodactylioceras davoei
- zone of Tragophylloceras ibex
- zone of Uptonia jamesoni
Uptonia is an extinct genus of cephalopod belonging to the Ammonite subclass....
In the
Tethys domainThe Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:...
, the Pliensbachian contains six biozones:
- zone of Emaciaticeras emaciatum
- zone of Arieticeras algovianum
Arieticeras is an extinct genus of cephalopod belonging to the Ammonite subclass....
- zone of Fuciniceras lavinianum
Fuciniceras is an extinct genus of cephalopod belonging to the Ammonite subclass....
- zone of Prodactylioceras davoei
- zone of Tragophylloceras ibex
- zone of Uptonia jamesoni
Ornithischians
| Ornithischians of the Pliensbachian |
| Taxa |
Presence |
Location |
Description |
Images |
- Bienosaurus
Bienosaurus was a dinosaur from the Early Jurassic. The genus was an armored dinosaur from the Lower Lufeng Formation in Yunnan Province in China.-Discovery and species:...
|
|
Lower Lufeng Formation, Yunnan, China |
A dubious basal thyreophoranThe Thyreophora were a subgroup of the ornithischian dinosaurs...
|
|
|
Tatisaurus Tatisaurus is a genus of dinosaur from the Early Jurassic from the Lower Lufeng Formation in Yunnan Province in China. Little is known as the remains are fragmentary.-Discovery and species:...
|
|
Lower Lufeng Formation, Yunnan, China |
Description based on only a partial left mandible with teeth, a dubious basal thyreophoranThe Thyreophora were a subgroup of the ornithischian dinosaurs...
|
Theropoda
| Theropods of the Pliensbachian |
| Taxa |
Presence |
Location |
Description |
Images |
- Cryolophosaurus
Cryolophosaurus was a large theropod dinosaur, with a bizarre crest on its head that looked like a Spanish comb...
|
|
Hanson Formation, Antarctica |
The earliest known tetanuran. About 6 to 8 meters (20 to 26 feet) long with a high, narrow skull and a peculiar nasal crest just over the eyes |
|
- Dilophosaurus
Dilophosaurus was a theropod dinosaur from the Pliensbachian stage of the Early Jurassic Period. The name means 'two-crested lizard', from the two crests of the animal...
|
SinemurianIn the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...
to Pliensbachian |
ArizonaThe State of Arizona is a state located in the southwestern region of the United States. The capital and largest city is Phoenix. The second largest city is Tucson, followed in size by the four Phoenix metropolitan area cities of Mesa, Glendale, Chandler, and Scottsdale.Arizona was the 48th and...
, USA; YunnanYunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately 394,000 square kilometers . The capital of the province is Kunming...
, China |
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. |
Literature
;
2004:
A Geologic Time Scale 2004,
Cambridge University PressCambridge University Press is a printer and publisher granted a Royal Letters Patent by Henry VIII in 1534. It is the world's oldest continually operating book publisher...
.;
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);
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.;
1856-1858:
Die Juraformation Englands, Frankreichs und des südwestlichen Deutschlands: nach ihren einzelnen Gliedern engetheilt und verglichen, 857 pp., Ebner & Seubert, Stuttgart.
External links