Kimmeridgian

System	Series	Stage	Age (Ma)
Cretaceous	Lower	Berriasian	younger
Jurassic	Upper	Tithonian	145.5–150.8
		Kimmeridgian	150.8–155.7
		Oxfordian	155.7–161.2
	Middle	Callovian	161.2–164.7
		Bathonian	164.7–167.7
		Bajocian	167.7–171.6
		Aalenian	171.6–175.6
	Lower	Toarcian	175.6–183.0
		Pliensbachian	183.0–189.6
		Sinemurian	189.6–196.5
		Hettangian	196.5–199.6
Triassic	Upper	Rhaetian	older
Subdivision of the Jurassic system according to the IUGS, as of July 2009.

In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma (million years ago). The Kimmeridgian follows the Oxfordian and precedes the Tithonian.^[1]

1 Stratigraphic definition
- 1.1 Subdivision
2 Palaeontology
3 References

Stratigraphic definition

The Kimmeridgian stage takes its name from the village of Kimmeridge on the Dorset coast, England. The name was introduced in literature by Swiss geologist Jules Thurmann in 1832. The Kimmeridge Clay Formation has its name from the same type location. It is the source for about 95% of the petroleum in the North Sea.

Historically the term Kimmeridgian has been used in two different ways. The base of the interval is the same but the top was defined by British stratigraphers as the base of the Portlandian (sensu anglico) whereas in France the top was defined as the base of the Tithonian (sensu gallico). The differences have not yet been fully resolved, but Tithonian is now seen as the uppermost stage of the Jurassic in the timescale of the ICS.^[2]

The base of the Kimmeridgian is at the first appearance of ammonite species Pictonia baylei in the stratigraphic column. A global reference profile for the base (the GSSP of the Kimmeridgian stage) had in 2009 not yet been assigned. The top of the Kimmeridgian (the base of the Tithonian) is at the first appearance of ammonite species Hybonoticeras hybonotum. It also coincides with the top of magnetic anomaly M22An.

Subdivision

The Kimmeridgian is sometimes subdivided into Upper and Lower substages. In the Tethys domain, the Kimmeridgian contains seven ammonite biozones:

zone of Hybonoticeras beckeri
zone of Aulacostephanus eudoxus
zone of Aspidoceras acanthicum
zone of Crussoliceras divisum
zone of Ataxioceras hypselocyclum
zone of Sutneria platynota
zone of Idoceras planula

Palaeontology

†Ankylosaurs

Ankylosaurs of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Gargoyleosaurus		Morrison Formation, Wyoming, USA	The smallest and the earliest well-known ankylosaur. Its skull measures only 29 cm in length, and its total body length is an estimated three to four meters.
Mymoorapelta Mymoorapelta maysi		Morrison Formation, Colorado, USA	A poorly known early ankylosaurian.

Birds

Birds of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Archaeopteryx Archaeopteryx lithographica

†Ornithopods

Ornithopoda of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Camptosaurus	Kimmeridgian to ?Berriasian	Wyoming, USA; England; France	Camptosaurus could be more than 7.9 meters long (26 ft), and 2.0 meters tall (6.7 ft) at the hips. It had heavy bodies but, as well as walking on four legs (quadrupedal), they could rear up to walk on two legs (bipedal). This genus is probably closely related to the ancestor of the later iguanodontid and hadrosaurid dinosaurs. It probably ate cycads with its parrot-like beak.
Drinker
Dryosaurus
Othnielia
Othnielosaurus
Phyllodon

†Plesiosaurs

Plesiosaurs of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Liopleurodon
Pliosaurus
Colymbosaurus
Kimmerosaurus

†Sauropods

†Sauropods of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Amphicoelias Amphicoelias fragillimus?
Apatosaurus
Brachiosaurus
Camarasaurus
Dicraeosaurus
Diplodocus
Dystrophaeus
Eobrontosaurus
Europasaurus Europasaurus holgeri

†Stegosaurs

Stegosaurs of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Dacentrurus		England, France, Spain, Portugal	A large stegosaurid
Gigantspinosaurus		Upper Shaximiao Formation, Sichuan, China	Had relatively small dorsal plates and greatly enlarged shoulder spines, twice the length of the shoulder blades. Estimated to have been about 4 metres long.
Hesperosaurus		Morrison Formation, Wyoming, USA	Had alternating plates on its back and four spikes on its tail. Appears more closely related to Dacentrurus than Stegosaurus.
Kentrosaurus		Tanzania	A 4 meter long stegosaurian with spikes on its flanks. The length of the thigh bone compared with the rest of the leg indicates that Kentrosaurus was a slow and inactive dinosaur.
Monkonosaurus		Loe-ein Formation, Tibet, China	The fragmentary condition of the only known skeleton places doubt on the validity of this genus
Stegosaurus	Kimmeridgian to Early Tithonian	Morrison Formation, Colorado, Utah, Wyoming, USA	Averaging around 9 metres (30 ft) long and 4 metres (14 ft) tall, the quadrupedal Stegosaurus is one of the most easily identifiable dinosaurs, due to the distinctive double row of kite-shaped plates rising vertically along its arched back and the two pairs of long spikes extending horizontally near the end of its tail.

†Thalattosuchians

Thalattosuchians of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Dakosaurus D. maximus		Germany	type species of the genus, is known from Western Europe (England, France, Switzerland and Germany) of the Late Jurassic (Late Kimmeridgian-Early Tithonian).
Geosaurus G. suevicus		Germany	A relatively small metriorhynchid genus. No known species of Geosaurus attained lengths in excess of 3 meters (10 feet).
Machimosaurus
Metriorhynchus M. acutus M. geoffroyii M. hastifer M. palpebrosus		England, France and Switzerland	An opportunistic carnivore that fed on fish, belemnites and other marine animals and possible carrion. Metriorhynchus grew to an average adult length of 3 meters (9.6 feet).
Steneosaurus

†Theropods (non-avian)

†Non-avian theropods of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Aviatyrannis Aviatyrannis jurassica
Ceratosaurus
Coelurus Coelurus fragilis		Morrison Formation, Wyoming	Small theropod about 2 metres in length
Elaphrosaurus Elaphrosaurus bambergi		Tendaguru Beds, Tanzania	Probably a ceratosaur about 6 meters long
Stokesosaurus Stokesosaurus clevelandi
Torvosaurus Torvosaurus tanneri
Allosaurus

Nautiloids

Nautiloids of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Somalinautilus

†Ammonites

Ammonites of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Lithacosphinctes

†Belemnites

Belemnites of the Kimmeridgian
Taxa	Presence	Location	Description	Images
Produvalia

Palaeontological sites

Guimarota

References

Notes

^ For a detailed version of the ICS' timescale, see Gradstein et al. (2004)
^ INTERNATIONAL SUBCOMMISSION ON JURASSIC STRATIGRAPHY, Newsletter 31, Edited by Nicol Morton and Paul Bown, August 2004

Literature

Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
Thurmann, J.; 1832: Sur Les Soulèvemens Jurassiques Du Porrentruy: Description Géognostique de la Série Jurassique et Théorie Orographique du Soulèvement, Mémoires de la Société d'histoire naturelle de Strasbourg 1: pp 1–84, F. G. Levrault, Paris.(French)

External links

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

Jurassic Period
Lower/Early Jurassic	Middle Jurassic	Upper/Late Jurassic
Hettangian \| Sinemurian Pliensbachian \| Toarcian	Aalenian \| Bajocian Bathonian \| Callovian	Oxfordian \| Kimmeridgian Tithonian

Geologic history of Earth

Precambrian (4.57 Gya – 542 Mya)

In left column are eons; right column: bold are eras; not bold are periods:

Hadean (4.57 – 4 Gya)	(informal)

Archean (4 – 2.5 Gya)	Eoarchean (4 – 3.6 Gya) Paleoarchean (3.6 – 3.2 Gya) Mesoarchean (3.2 – 2.8 Gya) Neoarchean (2.8 – 2.5 Gya)

Proterozoic (2.5 Gya – 542 Mya)	Paleoproterozoic (2.5 – 1.6 Gya): Siderian (2.5 – 2.3 Gya) · Rhyacian (2.3 – 2.05 Gya) · Orosirian (2.05 – 1.8 Gya) · Statherian (1.8 – 1.6 Gya) Mesoproterozoic (1.6 – 1 Gya): Calymmian (1.6 – 1.4 Gya) · Ectasian (1.4 – 1.2 Gya) · Stenian (1.2 – 1 Gya) Neoproterozoic (1 Gya – 542 Mya): Tonian (1 Gya – 850 Mya) · Cryogenian (850 – 635 Mya) · Ediacaran (635 – 542 Mya)

Mya = millions years ago. Gya = billions years ago.

Phanerozoic (542 – 0 Mya)

In horizontal bars are eras; in left column are periods; right column: bold are epochs; not bold not italic are ages; italic are chrons:

Paleozoic (542 – 251 Mya)

Cambrian (542 – 488.3 Mya)	Terreneuvian (542 – 521 Mya) (de): Fortunian (542 – 528 Mya) (de) · Age 2* (528 – 521 Mya) *Epoch 2 (521 – 510 Mya)*: Age 3 (521 – 515 Mya) · Age 4* (515 – 510 Mya) *Epoch 3 (510 – 499 Mya)*: Age 5 (510 – 506.5 Mya) · Drumian (506.5 – 503 Mya) (de) · Guzhangian (503 – 499 Mya) (de) Furongian (499 – 488.3 Mya): Paibian (499 – 496 Mya) · Jiangshanian (496 – 492 Mya) (de) · Age 10* (492 – 488.3 Mya)

Ordovician (488.3 – 443.7 Mya)	Early Ordovician (488.3 – 471.8 Mya): Tremadocian (488.3 – 478.6 Mya) · Floian (478.6 – 471.8 Mya) Middle Ordovician (471.8 – 460.9 Mya): Dapingian (471.8 – 468.1 Mya) · Darriwilian (468.1 – 460.9 Mya) Late Ordovician (460.9 – 443.7 Mya): Sandbian (460.9 – 455.8 Mya) · Katian (455.8 – 445.6 Mya) · Hirnantian (445.6 – 443.7 Mya)

Silurian (443.7 – 416 Mya)	Llandovery (443.7 – 428.2 Mya): Rhuddanian (443.7 – 439 Mya) · Aeronian (439 – 436 Mya) · Telychian (436 – 428.2 Mya) Wenlock (428.2 – 422.9 Mya): Sheinwoodian (428.2 – 426.2 Mya) · Homerian (426.2 – 422.9 Mya) Ludlow (422.9 – 418.7 Mya): Gorstian (422.9 – 421.3 Mya) · Ludfordian (421.3 – 418.7 Mya) Pridoli (418.7 – 416 Mya)

Devonian (416 – 359.2 Mya)	Early Devonian (416 – 397.5 Mya): Lochkovian (416 – 411.2 Mya) · Pragian (411.2 – 407 Mya) · Emsian (407 – 397.5 Mya) Middle Devonian (397.5 – 385.3 Mya): Eifelian (397.5 – 391.8 Mya) · Givetian (391.8 – 385.3 Mya) Late Devonian (385.3 – 359.2 Mya): Frasnian (385.3 – 374.5 Mya) · Famennian (374.5 – 359.2 Mya)

Carboniferous (359.2 – 299 Mya)	Mississippian (359.2 – 318.1 Mya): Tournaisian / Early Mississippian (359.2 – 345.3 Mya) · Viséan / Middle Mississippian (345.3 – 328.3 Mya) · Serpukhovian / Late Mississippian (328.3 – 318.1 Mya) Pennsylvanian (318.1 – 299 Mya): Bashkirian / Early Pennsylvanian (318.1 – 311.7 Mya) · Moscovian / Middle Pennsylvanian (311.7 – 307.2 Mya) · Late Pennsylvanian (307.2 – 299 Mya): Kasimovian (307.2 – 303.4 Mya) · Gzhelian (303.4 – 299 Mya)

Permian (299 – 251 Mya)	Cisuralian (299 – 270.6 Mya): Asselian (299 – 294.6 Mya) · Sakmarian (294.6 – 284.4 Mya) · Artinskian (284.4 – 275.6 Mya) · Kungurian (275.6 – 270.6 Mya) Guadalupian (270.6 – 260.4 Mya): Roadian (270.6 – 268 Mya) · Wordian (268 – 265.8 Mya) · Capitanian (265.8 – 260.4 Mya) Lopingian (260.4 – 251 Mya): Wuchiapingian (260.4 – 253.8 Mya) · Changhsingian (253.8 – 251 Mya)

Mesozoic (251 – 65.5 Mya)

Triassic (251 – 199.6 Mya)	Early Triassic (251 – 245.9 Mya): Induan (251 – 249.5 Mya) · Olenekian (249.5 – 245.9 Mya) Middle Triassic (245.9 – 228.7 Mya): Anisian (245.9 – 237 Mya) · Ladinian (237 – 228.7 Mya) Late Triassic (228.7 – 199.6 Mya): Carnian (228.7 – 216.5 Mya) · Norian (216.5 – 203.6 Mya) · Rhaetian (203.6 – 199.6 Mya)

Jurassic (199.6 – 145.5 Mya)	Early Jurassic (199.6 – 175.6 Mya): Hettangian (199.6 – 196.5 Mya) · Sinemurian (196.5 – 189.6 Mya) · Pliensbachian (189.6 – 183 Mya) · Toarcian (183 – 175.6 Mya) Middle Jurassic (175.6 – 161.2 Mya): Aalenian (175.6 – 171.6 Mya) · Bajocian (171.6 – 167.7 Mya) · Bathonian (167.7 – 164.7 Mya) · Callovian (164.7 – 161.2 Mya) Late Jurassic (161.2 – 145.5 Mya): Oxfordian (161.2 – 155.6 Mya) · Kimmeridgian (155.6 – 150.8 Mya) · Tithonian (150.8 – 145.5 Mya)

Cretaceous (145.5 – 65.5 Mya)	Early Cretaceous (145.5 – 99.6 Mya): Berriasian (145.5 – 140.2 Mya) · Valanginian (140.2 – 133.9 Mya) · Hauterivian (133.9 – 130 Mya) · Barremian (130 – 125 Mya) · Aptian (125 – 112 Mya) · Albian (112 – 99.6 Mya) Late Cretaceous (99.6 – 65.5 Mya): Cenomanian (99.6 – 93.6 Mya) · Turonian (93.6 – 88.6 Mya) · Coniacian (88.6 – 85.8 Mya) · Santonian (85.8 – 83.5 Mya) · Campanian (83.5 – 70.6 Mya) · Maastrichtian (70.6 – 65.5 Mya)

Cenozoic (65.5 – 0 Mya)

Paleogene, Neogene and early Pleistocene comprise former Tertiary* (65.5 – 1.8 Mya) period. Gelasian and Calabrian comprise Early Pleistocene (2.588 Mya – 781 kya) subepoch.

Paleogene (65.5 – 23.03 Mya)	Paleocene (65.5 – 55.8 Mya): Danian (65.5 – 61.1 Mya) · Selandian (61.1 – 58.7 Mya) · Thanetian (58.7 – 55.8 Mya) Eocene (55.8 – 33.9 Mya): Ypresian (55.8 – 48.6 Mya) · Lutetian (48.6 – 40.4 Mya) · Bartonian (40.4 – 37.2 Mya) · Priabonian (37.2 – 33.9 Mya) Oligocene (33.9 – 23.03 Mya): Rupelian (33.9 – 28.4 Mya) · Chattian (28.4 – 23.03 Mya)

Neogene (23.03 – 2.588 Mya)	Miocene (23.03 – 5.332 Mya): Aquitanian (23.03 – 20.43 Mya) · Burdigalian (20.43 – 15.97 Mya) · Langhian (15.97 – 13.82 Mya) · Serravallian (13.82 – 11.608 Mya) · Tortonian (11.608 – 7.246 Mya) · Messinian (7.246 – 5.332 Mya) Pliocene (5.332 – 2.588 Mya): Piacenzian (5.332 – 3.6 Mya) · Zanclean (3.6 – 2.588 Mya)

Quaternary (2.588 – 0 Mya)	Pleistocene (2.588 Mya – 11.4 kya): Gelasian (2.588 – 1.806 Mya) · Calabrian (1.806 Mya – 781 kya) · Middle Pleistocene / Ionian (781 – 126 kya) · Late Pleistocene / Tarantian (126 – 11.4 kya): Oldest Dryas (18 – 14.67 kya) · Bølling* (14.67 – 14 kya) · Older Dryas* (14 – 13.7 kya) · Allerød* (13.7 – 12.8 kya) · Younger Dryas* (12.8 – 11.4 kya)* Holocene (11.4 – 0 kya): Preboreal (11.4 – 9 kya) · Boreal* (9 – 8 kya) · Atlantic* (8 – 5 kya) · Subboreal* (5 – 2.5 kya) · Subatlantic* (2.5 – 0 kya)*

kya = thousands years ago. Mya = millions years ago. * Not officially recognized by the I.C.S.

Source: International Stratigraphic Chart. International Commission on Stratigraphy. Retrieved 8 February 2008.