In the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic

Early Jurassic

The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...

 epoch

Epoch (geology)

An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

 or series

Series (stratigraphy)

Series 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...

. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian

Hettangian

The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...

 and is followed by the Pliensbachian

Pliensbachian

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 189.6 ± 1.5 Ma and 183 ± 1.5 Ma . The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.The...

.

In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias

Lias Group

The Lias Group or Lias is a lithostratigraphic unit found in a large area of western Europe, including the British Isles, the North Sea, the low countries and the north of Germany...

, in Great Britain known as the Blue Lias

Blue Lias

The Blue Lias is a geologic formation in southern, eastern and western England and parts of South Wales, part of the Lias Group. The Blue Lias consists of a sequence of limestone and shale layers, laid down in latest Triassic and early Jurassic times, between 195 and 200 million years ago...

.

Stratigraphic definitions

The Sinemurian stage was defined and introduced into scientific literature by French palaeontologist Alcide d'Orbigny

Alcide d'Orbigny

Alcide Charles Victor Marie Dessalines d'Orbigny was a French naturalist who made major contributions in many areas, including zoology , palaeontology, geology, archaeology and anthropology....

 in 1842. It takes its name from the French town of Semur-en-Auxois

Semur-en-Auxois

Semur-en-Auxois is a commune of the Côte-d'Or department in eastern France.Semur-en-Auxois has a medieval core, built on a pink granite bluff more than half-encircled by the River Armançon...

, near Dijon

Dijon

Dijon is a city in eastern France, the capital of the Côte-d'Or département and of the Burgundy region.Dijon is the historical capital of the region of Burgundy. Population : 151,576 within the city limits; 250,516 for the greater Dijon area....

. The calcareous

Calcareous

Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...

 soil formed from the Jurassic limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 of the region is in part responsible for the character of the classic Sancerre wines

Sancerre (wine)

Sancerre is a French wine Appellation d'origine contrôlée for wine produced in the environs of Sancerre in the eastern part of the Loire valley, southeast of Orléans. Almost all of the appellation lies on the left bank of the Loire, opposite Pouilly-Fumé. It is well regarded for and primarily...

.

The base of the Sinemurian stage is at the first appearance of the ammonite

Ammonite

Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...

 genera

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Vermiceras and Metophioceras in the stratigraphic record. A global reference profile (GSSP or golden spike) for the Sinemurian stage is located in a cliff north of the hamlet of East Quantoxhead

East Quantoxhead

East Quantoxhead is a village in West Somerset, from West Quantoxhead, east of Williton, and west of Bridgwater, within the Quantock Hills Area of Outstanding Natural Beauty in Somerset, England.-History:...

, 6 kilometres east of Watchet

Watchet

Watchet is a harbour town and civil parish in the English county of Somerset, with an approximate population of 4,400. It is situated west of Bridgwater, north-west of Taunton, and east of Minehead. The parish includes the hamlet of Beggearn Huish...

, Somerset

Somerset

The ceremonial and non-metropolitan county of Somerset in South West England borders Bristol and Gloucestershire to the north, Wiltshire to the east, Dorset to the south-east, and Devon to the south-west. It is partly bounded to the north and west by the Bristol Channel and the estuary of the...

, England

England

England 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, with the North Sea to the east and the English Channel to the south separating it from continental...

.

The top of the Sinemurian (the base of the Pliensbachian) is at the first appearances of the ammonite species Bifericeras donovani

Bifericeras

Bifericeras is a Lower Jurassic ammonite beloning to the family Eoderoceratidae, and sometimes placed in the subfamily Xipherceratinae. Whorls are strongly depressed, but still evolute in coiling...

and ammonite genus Apoderoceras

Apoderoceras

Apoderoceras is an extinct genus of cephalopod belonging to the Ammonite subclass....

.

The Sinemurian contains six ammonite biozone

Biozone

Biostratigraphic units or Biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa....

s in the Tethys domain

Tethys Ocean

The 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:...

:

• zone of Echioceras raricostatum
  Echioceras
  Echioceras is an extinct genus of ammonite from the Early Jurassic of Europe and North America.-References:* Fossils by David Ward* Dinosaur Encyclopedia by Jayne Parsons-External links:...
  
  
• zone of Oxynotoceras oxynotum
• zone of Caenisites turneri
• zone of Arnioceras semicostatum
  Arnioceras
  Arnioceras is an extinct genus of cephalopod belonging to the Ammonite subclass....
  
  
• zone of Arietites bucklandi
  Arietites
  Arietites is a genus of massive, giant evolute, psiloceratacean ammonites in the family Arietitidae in which whorls are subquadrate and transversely ribbed and low keels in tripicate, separated by a pair of longitudinal grooves, run along the venter...
  
  

†Ichthyosaurs

Ichthyosauria of the Sinemurian
Taxa	Presence	Location	Description	Images
Ichthyosaurus Ichthyosaurus Ichthyosaurus is an extinct genus of ichthyosaur from the Early Jurassic of Europe . It is among the best known ichthyosaur genera, with the Order Ichthyosauria being named after it...	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Belgium, England, Germany	Among the best known ichthyosaur genera, was smaller than most of its relatives, measuring 2 m (6 ft 8 inches) in length.

Mammaliaformes

Mammaliaformes Mammaliaformes Mammaliaformes is a clade that contains the mammals and their closest extinct relatives. Phylogenetically, it is defined as a clade including the most recent common ancestor of Sinoconodon, morganuconodonts, docodonts, Monotremata, Marsupialia, Placentalia, extinct members of this clade, and all...  of the Sinemurian
Taxa	Presence	Location	Description	Images
Hadrocodium Hadrocodium Hadrocodium wui is an extinct basal mammal species that lived during the Lower Jurassic in what is now the Yunnan province of China...		Yunnan, China	The earliest known example of several features distinctive to mammals, including mammal-like mandible and middle-ear structures and a relatively large brain cavity.
Kuehneotherium Kuehneotherium Kuehneotherium was an early symmetrodont whose fossils have been found in Greenland, France and Luxembourg. It is known only from an upper molar as well as nine additional teeth and four dentary fragments.-Further reading:...	From Norian Norian The Norian is a division of the Triassic geological period. It has the rank of an age or stage . The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.-Stratigraphic definitions:The Norian was named after the Noric Alps in...  to Sinemurian	Greenland and Western Europe	A Late Triassic-Early Jurassic symmetrodonta Symmetrodonta Symmetrodonta is a basal group of Mesozoic mammals characterized by the triangular aspect of the molars when viewed from above and the absence of a well-developed talonid. The traditional group of symmetrodonts ranges in age from the latest Triassic to the Late Cretaceous. One species,... n.

†Ornithischians

Ornithischians of the Sinemurian
Taxa	Presence	Location	Description	Images
Abrictosaurus Abrictosaurus Abrictosaurus is a genus of heterodontosaurid dinosaur from the Early Jurassic Period of what is now southern Africa. It was a small bipedal herbivore or omnivore, approximately 1.2 meters long, and weighing less than 45 kilograms .This dinosaur is known from the fossil remains of only...	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Upper Elliot Formation Upper Elliot Formation The Upper Elliot Formation is a geological formation dating to roughly between 200 to 190 million years ago and covering the Hettangian to Sinemurian stages. The Upper Elliot Formation is found in South Africa and Lesotho and is a member of the Stormberg Group. It consists mainly of limestone,... , Lesotho and Cape Province, South Africa	Considered the most basal member of the family Heterodontosauridae
Fabrosaurus Fabrosaurus Fabrosaurus ) was a genus of herbivorous dinosaur which lived during the Early Jurassic . As the only fossil known of it is a partial jawbone with three teeth, Fabrosaurus is a nomen dubium and may in fact be the same as Lesothosaurus.Fabrosaurus was around 1 meter long...	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Lesotho	As the only fossil known of it is a partial jawbone with three teeth, Fabrosaurus is a nomen dubium and may in fact be the same as Lesothosaurus.
Geranosaurus Geranosaurus Geranosaurus is a genus of ornithischian dinosaur from the Early Jurassic. It is known only from a jaw bone and limb elements discovered in South Africa. Because of the limited remains, it is considered a nomen dubium...		Clarence Formation, Cape Province, South Africa	With few remains, it is considered a nomen dubium. It is classified as an ornithischian based on the jaw.
Lanasaurus	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Upper Elliot Formation Upper Elliot Formation The Upper Elliot Formation is a geological formation dating to roughly between 200 to 190 million years ago and covering the Hettangian to Sinemurian stages. The Upper Elliot Formation is found in South Africa and Lesotho and is a member of the Stormberg Group. It consists mainly of limestone,... , Orange Free State, South Africa	A heterodontosaurid ornithischian
Lusitanosaurus Lusitanosaurus Lusitanosaurus is a genus of basal thyreophoran dinosaur from the Early Jurassic of Portugal.The genus was first described by Albert-Félix de Lapparent and Georges Zbyszewski in 1957. The type species is Lusitanosaurus liasicus. The generic name is derived from Lusitania, the ancient Latin name...	Dated disputed	Unknown location in Portugal Portugal Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...	Only known from a partial snout with teeth
Lycorhinus Lycorhinus Lycorhinus is a genus of heterodontosaurid ornithischian dinosaur hailing from the Early Jurassic strata of the Elliot Formation located in the Cape Province, South Africa....	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Upper Elliot Formation Upper Elliot Formation The Upper Elliot Formation is a geological formation dating to roughly between 200 to 190 million years ago and covering the Hettangian to Sinemurian stages. The Upper Elliot Formation is found in South Africa and Lesotho and is a member of the Stormberg Group. It consists mainly of limestone,... , Cape Province, South Africa	A small herbivore dinosaur despite long canines it sported in its jaws; due to this unique characteristic it is very clearly allied to Heterodontosaurus
Merosaurus Merosaurus "Merosaurus" is the informal name given to an as yet undescribed genus of dinosaur from the Early Jurassic ....		England	Disputed, considered by some to be a tetanuran theropod
Scelidosaurus Scelidosaurus Scelidosaurus is a genus of quadrupedal, lightly plated, herbivorous dinosaur about long. It lived during the Early Jurassic Period, during the Hettangian to Sinemurian stages around 199.6 to 194 million years ago. Its fossils have been found in both England and in Arizona, in the United...	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Charmouth Charmouth Charmouth is a village at the mouth of the River Char in West Dorset, England, with a population of 1,687 according to the 2001 census.-The village:... , West Dorset, England; Kayenta Formation Kayenta Formation The Kayenta Formation is a geologic layer in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. This rock formation is particularly prominent in southeastern Utah, where it is seen in the... , Arizona, USA	A genus of quadrupedal, lightly plated, herbivorous dinosaur about 4 meters long (13 ft)
Stormbergia Stormbergia Stormbergia is a genus of early ornithischian dinosaur known from the upper Elliot Formation of South Africa and Lesotho, named by Richard Butler in 2005...	From Hettangian Hettangian The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...  to Sinemurian	Stormberg Series Formations, South Africa, Lesotho	A primitive ornithischian, about 2 meters (6 ft 6 in) long. The proportions of the posterior limbs show differences with those of Lesothosaurus Lesothosaurus Lesothosaurus is an herbivorous ornithischian dinosaur. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from Lesotho". The genus is monotypic, having only one valid species, Lesothosaurus diagnosticus, within the genus.... , and reveal a lower ability to run

†Plesiosaurs

Plesiosauria Plesiosauria Plesiosauria is an order of Mesozoic marine reptiles. Plesiosaurs first appeared in the Early Jurassic Period and became especially common during the Jurassic Period, thriving until the K-T extinction at the end of the Cretaceous Period.The name "plesiosaur" is used to refer to the order...  of the Sinemurian
Taxa	Presence	Location	Description	Images
Eretmosaurus Eretmosaurus Eretmosaurus is an extinct genus of plesiosaur....		Granby Granby, Nottinghamshire Granby is a small village in the Rushcliffe district of Nottinghamshire. It lies in the Vale of Belvoir.-Population and facilities:The parish has a population of about 300 people and is situated about 14 miles east of Nottingham. Census returns suggest a peak population of 439 in the 1891 census... , Leicestershire, England	May have been a rhomaleosaurid Rhomaleosaurus Rhomaleosaurus is an extinct genus of Early Jurassic rhomaleosaurid pliosauroid known from Northamptonshire and from Yorkshire of the United Kingdom. It was first named by Harry Seeley in 1874 and the type species is Rhomaleosaurus cramptoni... , pliosaurid or elasmosaurid
Plesiosaurus Plesiosaurus Plesiosaurus was a genus of large marine sauropterygian reptile that lived during the early part of the Jurassic Period, and is known by nearly complete skeletons from the Lias of England...  dolichodeirus	Sinemurian and Toarcian Toarcian The 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...	Lyme Regis Lyme Regis Lyme Regis is a coastal town in West Dorset, England, situated 25 miles west of Dorchester and east of Exeter. The town lies in Lyme Bay, on the English Channel coast at the Dorset-Devon border... , Dorset, England	A large (about 3 to 5 meters long), marine sauropterygian reptile, it was distinguished by its small head, long and slender neck, broad turtle like body, a short tail, and two pairs of large, elongated paddles

Theropoda

Theropods of the Sinemurian
Taxa	Presence	Location	Description	Images
Dilophosaurus Dilophosaurus Dilophosaurus was a theropod dinosaur from the Sinemurian stage of the Early Jurassic Period, about 193 million years ago. The first specimens were described in 1954, but it was not until over a decade later that the genus received its current name...	Sinemurian to Pliensbachian Pliensbachian 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 189.6 ± 1.5 Ma and 183 ± 1.5 Ma . The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.The...	Arizona Arizona Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix... , USA; Yunnan Yunnan Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with... , 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.
Sarcosaurus Sarcosaurus Sarcosaurus is a genus of theropod dinosaur, either a coelophysoid or a basal ceratosaur, roughly 3.5 meters long. It lived during the Sinemurian stage of the Early Jurassic, about 194 million years ago....	Sinemurian	Leicestershire Leicestershire Leicestershire is a landlocked county in the English Midlands. It takes its name from the heavily populated City of Leicester, traditionally its administrative centre, although the City of Leicester unitary authority is today administered separately from the rest of Leicestershire... , England	Measured around 3.5 meters (12 ft) long. The most distinctive characteristic of Sarcosaurus is its pelvis which is remarkably similar to the later Ceratosaurus Ceratosaurus Ceratosaurus meaning "horned lizard", in reference to the horn on its nose , was a large predatory theropod dinosaur from the Late Jurassic Period , found in the Morrison Formation of North America, in Tanzania and Portugal... .
Saltriosaurus Saltriosaurus Saltriosaurus is the informal name for a theropod dinosaur that lived during the Jurassic period. It was found in 1996, when Angelo Zanella discovered its remains in a quarry in Saltrio, in northern Italy. Very little is known about the dinosaur...	Sinemurian	Saltrio Saltrio Saltrio is a comune in the Province of Varese in the Italian region Lombardy, located about 50 km northwest of Milan and about 9 km northeast of Varese, on the border with Switzerland... , Northern Italy

Literature

; 2001: Global Stratotype Section and Point for base of the Sinemurian Stage (Lower Jurassic), Episodes 25(1), pp. 22-28, PDF; 2004: A Geologic Time Scale 2004, Cambridge University Press

Cambridge University Press

Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...

.; 1842: Paléontologie française. 1. Terrains oolitiques ou jurassiques, Bertrand, Paris.

External links

• GeoWhen Database - Sinemurian
• Lower Jurassic timescale, at the website of the subcommission for stratigraphic information of the ICS
• Stratigraphic chart of the Lower Jurassic, at the website of Norges Network of offshore records of geology and stratigraphy