The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by the Cenomanian stage and underlies the Coniacian stage.[3]

93.9 – 89.8 ± 0.3 Ma
Paleogeography of the late Turonian (90 Ma), showing the high sea level at the time
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the Ammonite Watinoceras devonense
Lower boundary GSSPRock Canyon, Colorado, USA
38°16′56″N 104°43′39″W / 38.2822°N 104.7275°W / 38.2822; -104.7275
GSSP ratifiedSeptember 2003[2]
Upper boundary definitionNot formally defined
Upper boundary definition candidatesFAD of the Inoceramid Bivalve Cremnoceramus rotundatus
Upper boundary GSSP candidate section(s)

At the beginning of the Turonian an oceanic anoxic event (OAE 2) took place, also referred to as the Cenomanian-Turonian boundary event or the "Bonarelli Event".

Stratigraphic definitionEdit

Lithographic limestone from the Gerofit Formation (Turonian) north of Makhtesh Ramon, southern Israel; a variety of Jerusalem stone (meleke).

The Turonian (French: Turonien) was defined by the French paleontologist Alcide d'Orbigny (1802–1857) in 1842. Orbigny named it after the French city of Tours in the region of Touraine (department Indre-et-Loire), which is the original type locality.

The base of the Turonian stage is defined as the place where the ammonite species Wutinoceras devonense first appears in the stratigraphic column. The official reference profile (the GSSP) for the base of the Turonian is located in the Rock Canyon anticline near Pueblo, Colorado (United States, coordinates: 38° 16' 56" N, 104° 43' 39" W).[4]

The top of the Turonian stage (the base of the Coniacian) is defined as the place in the stratigraphic column where the inoceramid bivalve species Cremnoceramus rotundatus first appears.


The Turonian is sometimes subdivided in Lower/Early, Middle and Upper/Late substages or subages. In the Tethys domain, it contains the following ammonite biozones:

Other important index fossils are species of the inoceramid genus Inoceramus (I. schloenbachi, I. lamarcki and I. labiatus). Inoceramids are bivalve Mollusca related to today's mussels.



Ankylosaurs of the Turonian
Taxa Presence Location Description Images
Bayan Shireh Formation, Mongolia


Avialans of the Turonian
Taxa Presence Location Description Images


Bissekty Formation, Uzbekistan A mid-sized enantiornithine, perhaps 20–25 cm long in life


Bissekty Formation, Uzbekistan


Turonian - Campanian Alberta and Saskatchewan, Canada; Alabama, Kansas, New Mexico and Texas, USA; Argentina; Central Asia The Cretaceous ecological equivalent of modern seabirds such as gulls, petrels, and skimmers. At 60 cm (2.0 ft), it was the size of a gull. Although the wings and breastbone are very modern in appearance (suggesting strong flight ability), the jaws retained numerous small, sharp teeth


Ceratopsia of the Turonian
Taxa Presence Location Description Images


Moreno Hill Formation, New Mexico, USA The earliest-known ceratopsian to have eyebrow horns and the oldest-known ceratopsian from North America, appears to have been roughly 3 to 3.5 meters (9.8 to 11.5 ft) long and 1 meter (3.3 feet) tall at the hips.


Crocodylomorpha of the Turonian
Taxa Presence Location Description Images




Turonian to Santonian Adamantina Formation, São Paulo, Brazil A terrestrial peirosaurid




Fergana Basin, Tajikistan; Bissekty Formation, Dzharakhuduk, Uzbekistan An early alligatoroid very similar to Diplocynodon from the Cenozoic.


Mammalia of the Turonian
Taxa Presence Location Description Images


Straight Cliffs Formation of Utah, US. Smaller than a mouse, thought to behave somewhat similar.


Ornithopoda of the Turonian
Taxa Presence Location Description Images


Cerro Lisandro Formation, Neuquén Province, Patagonia, Argentina A 2 metres (6.6 ft) long elasmarian


Turonian to Coniacian Gobi Desert, Mongolia and China Would have been 6 m (20 ft) long[1] and 2 m (6.6 ft) high when in the quadrupedal stance, and weighed 1,100–1,500 kg (2,400–3,300 lb). Like many hadrosaurs, it could switch between bipedal and quadrupedal stances, but unusually it had large spines protruding from the vertebrae.
Jeyawati Turonian Moreno Hill Formation, New Mexico A basal hadrosauroid


Turonian to early Coniacian Portezuelo Formation, Argentina A genus of basal iguanodont, a large bipedal herbivore


Cenomanian-Turonian Bajo Barreal Formation, Chubut, Argentina A hypsilophodontid or other basal ornithopod, Notohypsilophodon would have been a bipedal herbivore. Its size has not been estimated


Cenomanian-Turonian China A poorly known iguanodont


Plesiosauria of the Turonian
Taxa Presence Location Description Images


Ottawa County, Kansas Brachauchenius represents the last known occurrence of a pliosaur in North America.


Britton Formation (Cedar Hill), Texas, USA A 7–14 m (23–46 ft) long creature, was very similar to the related Elasmosaurus. It had a compact body with a short tail and large flippers. Its small skull had long, forward-facing teeth ideal for catching slippery fish and squid that came together outside of its mouth when the mouth was closed, and was placed atop a very long neck.


Morocco A genus of polycotylid plesiosaur


Carlile Shale, Russell County, Kansas

Polyptychodon hudsoni

Texas, USA A 10 metres (33 ft) long Brachaucheniin pliosaurid


High Atlas, Morocco A genus of polycotylid plesiosaur, the estimated total length of Thililua is 5.5 to 6 metres.


Pterosaurs of the Turonian
Taxa Presence Location Description Images


Upper Chalk, Kent, England


Albian-Turonian Chalk Formation, Kent and Cambridge Greensand, England


Squamata of the Turonian
Taxa Presence Location Description Images


Arcadia Park Shale, Texas, USA A basal, small, plesiopedal mososauroid


Arcadia Park Shale, Texas, USA A basal, small, lightly built mosasaur

Theropods (non-avialan)Edit

Theropods of the Turonian
Taxa Presence Location Description Images
Neuquén, Argentina An informally named abelisauroid ceratosaur.
Khara Khutul, Mongolia A therizinosaur.
Bayan Shireh Formation of Mongolia A therizinosaur.
Huincul Formation, Argentina A gigantic carcharodontosaurid carnosaur.
New Mexico, USA A therizinosaur.
Khan-Bogdsomona, Mongolia A large therizinosaur and one of the first described.
Kyzylkum Desert, Uzbekistan A small (250 kg) tyrannosauroid.
Uzbekistan A troodontid.
Bajo Barreal Formation, Chubut Province, Argentina A medium-sized abelisaurid ceratosaur.
New Mexico A small basal tyrannosauroid.


  1. ^ Super User. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. ^ Kennedy, W. J.; I. Walaszczyk; W. A. Cobban (2005). "The Global Boundary Stratotype Section and Point for the base of the Turonian Stage of the Cretaceous: Pueblo, Colorado, U.S.A." (PDF). Episodes. 28 (2): 93–104. doi:10.18814/epiiugs/2005/v28i2/003.
  3. ^ See Gradstein et al. (2004) for a detailed description of the ICS' timescale
  4. ^ The GSSP was established by Kennedy et al. (2005)


  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
  • Kennedy, W.J.; Walaszczyk, I. & Cobban, W.A.; 2005: The Global Boundary Stratotype Section and Point for the base of the Turonian Stage of the Cretaceous: Pueblo, Colorado, U.S.A., Episodes 28(2): pp 93–104.

External linksEdit