Turonian

From Wikipedia, the free encyclopedia
Jump to: navigation, search
System/
Period
Series/
Epoch
Stage/
Age
Age (Ma)
Paleogene Paleocene Danian younger
Cretaceous Upper/
Late
Maastrichtian 66.0–72.1
Campanian 72.1–83.6
Santonian 83.6–86.3
Coniacian 86.3–89.8
Turonian 89.8–93.9
Cenomanian 93.9–100.5
Lower/
Early
Albian 100.5–~113.0
Aptian ~113.0–~125.0
Barremian ~125.0–~129.4
Hauterivian ~129.4–~132.9
Valanginian ~132.9–~139.8
Berriasian ~139.8–~145.0
Jurassic Upper/
Late
Tithonian older
Subdivision of the Cretaceous system
according to the IUGS, as of July 2012.

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 93.5 ± 0.8 Ma and 89.3 ± 1 Ma (million years ago). The Turonian is preceded by the Cenomanian stage and underlies the Coniacian stage.[1]

At the beginning of the Turonian an anoxic event took place which is called the Cenomanian-Turonian boundary event or the "Bonarelli Event".

Stratigraphic definition[edit]

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

The Turonian (French: Turonien) was definied 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 Watinoceras 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 (USA, coordinates: 38° 16' 56" N, 104° 43' 39" W).[2]

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.

Subdivision[edit]

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.

Palaeontology[edit]

†Ankylosaurs[edit]

Ankylosaurs of the Turonian
Taxa Presence Location Description Images
Bayn Shire Formation, Mongolia

Birds (avian theropods)[edit]

Aves of the Turonian
Taxa Presence Location Description Images

Catenoleimus

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

Explorornis

Bissekty Formation, Uzbekistan

Ichthyornis

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 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

†Ceratopsians[edit]

Ceratopsia of the Turonian
Taxa Presence Location Description Images

Zuniceratops

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 long (10–11 ft) and 1 meter (3 ft) tall at the hips.

Crocodylomorphs[edit]

Crocodylomorpha of the Turonian
Taxa Presence Location Description Images

Baurusuchus

Montealtosuchus

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

Stratiosuchus

Mammals[edit]

Mammalia of the Turonian
Taxa Presence Location Description Images

Bryceomys

†Ornithopods[edit]

Ornithopoda of the Turonian
Taxa Presence Location Description Images

Bactrosaurus

Turonian to Coniacian Gobi Desert, Mongolia and China Would have been 6 m (20 ft) long[1] and 2 m (7 ft) high when in the quadrupedal stance, and weighed 1100 – 1500 kg (2400 - 3300 lb). Like many hadrosaurs, it could switch between bipedal and quadrupedal stances, but unusually it had large spines protruding from the vertebrae.

Macrogryphosaurus

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

Notohypsilophodon

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

Shuangmiaosaurus

Cenomanian-Turonian China A poorly known iguanodont

†Plesiosaurs[edit]

Plesiosauria of the Turonian
Taxa Presence Location Description Images

Libonectes

Britton Formation (Cedar Hill), Texas, USA A 7–14 m (23–47 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.

Manemergus

Morocco A genus of polycotylid plesiosaur

Polyptychodon hudsoni

Texas, USA

Thililua

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

Squamats[edit]

Squamata of the Turonian
Taxa Presence Location Description Images

Dallasaurus

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

Russellosaurus

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

†Theropods (non-avian)[edit]

Theropods of the Turonian
Taxa Presence Location Description Images
Rio Limay, Argentina

References[edit]

Notes[edit]

  1. ^ See Gradstein et al. (2004) for a detailed description of the ICS' timescale
  2. ^ The GSSP was established by Kennedy et al. (2005)

Literature[edit]

  • 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 links[edit]

Cretaceous Period
Lower/Early Cretaceous Upper/Late Cretaceous
Berriasian | Valanginian | Hauterivian
Barremian| Aptian | Albian
Cenomanian | Turonian | Coniacian
Santonian |Campanian | Maastrichtian