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.[2]

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

Age (Ma)
Paleogene Paleocene Danian younger
Cretaceous Upper/
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
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/
Tithonian older
Subdivision of the Cretaceous system
according to the ICS, as of 2017.[1]

Stratigraphic definition

Turonian Jerusalem Stone 031612
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).[3]

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.







Mammalia of the Turonian
Taxa Presence Location Description Images


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




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


Sauropods of the Turonian
Taxa Presence Location Description Images



Theropods (non-avialan)


  1. ^ Super User. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. ^ See Gradstein et al. (2004) for a detailed description of the ICS' timescale
  3. ^ 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 links


Baalsaurus (named after the dinosaur fossil site Baal in Argentina, which in turn is named after the ancient Phoenician god Baal) is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Neuquén Province, Patagonia, Argentina. The type and only known species is B. mansillai, with the specific name honoring the discoverer Juan Eduardo Mansilla, a museum technician at the Geology and Paleontology Museum of the National University of Comahue.

The holotype specimen, MUCPv-1460, is a mostly complete right dentary that was found in rocks of the upper Portezuelo Formation. The dentary is squared-off instead of curved when viewed from above or below, with the teeth crowded into the front of the jaw, making it similar to the jaw of Antarctosaurus, Brasilotitan, and to a lesser extent Bonitasaura. The specimen is currently held at the Geology and Paleontology Museum of the National University of Comahue, Parque Natural Geo-Paleontológico Proyecto Dino, Barreales Lake.


Carcharodontosaurids (from the Greek καρχαροδοντόσαυρος, carcharodontósauros: "shark-toothed lizards") were a group of carnivorous theropod dinosaurs. In 1931 Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids included some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled or slightly exceeded Tyrannosaurus in length. A 2015 paper by Christophe Hendrickx and colleagues gives a maximum length estimate of 14 meters (46 feet) for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have been at least 6 meters (20 feet) long.


Carnosauria is a large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs and their closest kin. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as Giganotosaurus and Tyrannotitan which are among the largest known predatory dinosaurs.

Distinctive characteristics of carnosaurs include large eyes, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia).

Carnosaurs first appeared in the Middle Jurassic, around 176 mya. The last definite known carnosaurs, the carcharodontosaurs, became extinct in the Turonian epoch of the Cretaceous, roughly 90 mya; reportedly later remains of carcharodontosaurids, from the Campanian and Maastrichtian epochs, are possibly misidentified remains of abelisaurids. The phylogenetically problematic megaraptorans, which may not be carnosaurs, became extinct around 84 mya. Remains probably belonging to carcharodontosaurids have been found from the late Maastrichtian

(70-66 Ma ago) in Brazil.


The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name.

As a unit of geologic time measure, the Cenomanian age spans the time between 100.5 ± 0.9 Ma and 93.9 ± 0.8 Ma (million years ago). In the geologic timescale it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts approximately at 95 M.a.

The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States.

At the end of the Cenomanian an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli Event", that is associated with a minor extinction event for marine species.

Cenomanian-Turonian boundary event

The Cenomanian-Turonian boundary event, or the Cenomanian-Turonian extinction event, the Cenomanian-Turonian anoxic event (OAE 2), and referred also as the Bonarelli Event, was one of two anoxic extinction events in the Cretaceous period. (The other being the earlier Selli Event, or OAE 1a, in the Aptian.) The OAE 2 occurred approximately 91.5 ± 8.6 Ma, though other estimates are given as 93–94 Ma. The Cenomanian-Turonian boundary has recently been refined to 93.9 ± 0.15 Ma There was a large carbon disturbance during this time period. However, apart from the carbon cycle disturbance, there were also large disturbances in the oxygen and sulfur cycles of the ocean.

The event brought about the extinction of the Pliosauridae, and most Ichthyosauria. Coracoids of Maastrichtian age were once interpreted by some authors as belonging to ichthyosaurs, but these have since been interpreted as plesiosaur elements instead. Although the cause is still uncertain, the result starved the Earth's oceans of oxygen for nearly half a million years, causing the extinction of approximately 27 percent of marine invertebrates, including certain planktic and benthic foraminifera, mollusks, bivalves, dinoflagellates and calcareous nannofossils. The global environmental disturbance that resulted in these conditions increased atmospheric and oceanic temperatures. Boundary sediments show an enrichment of trace elements, and contain elevated δ13C values.The Cenomanian and Turonian stages were first noted by D'Orbigny between 1843 and 1852. The global type section for this boundary is located in the Bridge Creek Limestone Member of the Greenhorn formation near Pueblo, Colorado, which are bedded with the Milankovitch orbital signature. Here, a positive carbon-isotope event is clearly shown, although none of the characteristic, organic-rich black shale is present. It has been estimated that the isotope shift lasted approximately 850 kyrs longer than the black shale event, which may be the cause of this anomaly in the Colorado type-section. A significantly expanded OAE2 interval from southern Tibet documents a complete, more detailed, and finer-scale structures of the positive carbon isotope excursion that contains multiple shorter-term carbon isotope stages amounting to a total duration of 820±25 kyrs.The boundary is also known as the Bonarelli event because of 1- to 2-meter layer of thick black shale that marks the boundary and was first studied by Guido Bonarelli in 1891. It is characterized by interbedded black shale, chert and radiolarian sands is estimated to span a 400,000-year interval. Planktic foraminifera do not exist in this Bonarelli level, and the presence of radiolarians in this section indicates relatively high productivity and an availability of nutrients.

One possible cause of this event is sub-oceanic volcanism, possibly the Caribbean large igneous province, with increased activity approximately 500,000 years earlier. During that period, the rate of crustal production reached its highest level for 100 million years. This was largely caused by the widespread melting of hot mantle plumes under the oceans at the base of the lithosphere. This resulted in the thickening of the oceanic crust in the Pacific and Indian Oceans. This volcanism would have sent large quantities of carbon dioxide into the atmosphere, leading to global warming. Within the oceans, the emission of SO2, H2S, CO2, and halogens would have increased the acidity of the water, causing the dissolution of carbonate, and a further release of carbon dioxide. When the volcanic activity declined, this run-away greenhouse effect would have likely been put into reverse. The increased CO2 content of the oceans could have increased organic productivity in the ocean surface waters. The consumption of this newly abundant organic life by aerobic bacteria would produce anoxia and mass extinction. The resulting elevated levels of carbon burial would account for the black shale deposition in the ocean basins.


The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by the Turonian and followed by the Santonian.


Elaltitan is an extinct genus of large lithostrotian titanosaur sauropod known from the Late Cretaceous (mid Cenomanian to Turonian stage) of Chubut Province, southern Argentina. It contains a single species, Elaltitan lilloi.


Ichthyopterygia ("fish flippers") was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle Triassic ancestors.Basal ichthyopterygians (prior to and ancestral to true Ichthyosauria) were mostly small (a meter or less in length) with elongated bodies and long, spool-shaped vertebrae, indicating that they swam in a sinuous, eel-like manner. This allowed for quick movements and maneuverability that were advantages in shallow-water hunting. Even at this early stage, they were already very specialised animals with proper flippers, and would have been incapable of movement on land.

These animals seem to have been widely distributed around the coast of the northern half of Pangea, as they are known the Late Olenekian and Early Anisian (early part of the Triassic period) of Japan, China, Canada, and Spitsbergen (Norway). By the later part of the Middle Triassic, they were extinct, having been replaced by their descendants, the true ichthyosaurs.


The Ichthyosauromorpha are an extinct clade of marine reptiles consisting of the Ichthyosauriformes and the Hupehsuchia, living during the Mesozoic.

The node clade Ichthyosauromorpha was first defined by Ryosuke Motani et. al. in 2014 as the group consisting of the last common ancestor of Ichthyosaurus communis and Hupehsuchus nanchangensis, and all its descendants. Their synapomorphies, unique derived traits, include: the presence of an anterior flange on the humerus and radius; the lower end of the ulna being as wide as or wider than the upper end, the forelimb being as long as or longer than the hindlimb, the hand having at least three quarters of the length of the upper arm and lower arm combined, the fibula extending behind the level of the thighbone, and the transverse process of the vertebral neural arch being reduced or absent.The Ichthyosauromorpha probably originated in China during the upper Lower Triassic period, about 248 million years ago. One branch consisted of the Hupehsuchia, and the other of the Ichthyosauriformes, of which Cartorhynchus was a basal member. Other ichthyosauriforms were the Ichthyopterygia, containing the Ichthyosauria and allies. The last ichthyosaurs probably became extinct in the middle Cretaceous.


Khunnuchelys was a genus of trionychine turtle from the Late Cretaceous of Asia. Three species are known, K. erinhotensis, the type species, K. kizylkumensis, and K. lophorhothon. K. erinhotensis lived in China from the late Turonian until the middle Campanian. K. kizylkumensis existed during the late Turonian of Uzbekistan. The third species, described in 2013 by Danilov et al., persisted from the early to middle Campanian of Kazakhstan.


Malarguesaurus is a genus of titanosauriform sauropod dinosaur from the Late Cretaceous of Mendoza Province, Argentina. Its fossils, consisting of tail vertebrae, chevrons, ribs, and limb bones, were found in the late Turonian-early Coniacian-age (~89 million years old) Portezuelo Formation of the Neuquén Group. The type species, described by González Riga et al. in 2008, is M. florenciae.


Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and in soil, rotting wood, under stones, or in trees.


Ornithomimidae (meaning "bird-mimics") is a group of theropod dinosaurs which bore a superficial resemblance to modern ostriches. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia and North America), though they have also been reported from the Wonthaggi Formation of Australia. The group first appeared in the Early Cretaceous.


Pliosauridae is a family of plesiosaurian marine reptiles from the Earliest Jurassic to the early Late Cretaceous (Hettangian to Turonian stages) of Australia, Europe, North America and South America. Past the Turonian, they may have been replaced by the mosasaurs. It was formally named by Harry G. Seeley in 1874.


Ponerinae is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including Dinoponera gigantea - one of the world's largest species of ant. Mated workers have replaced the queen as the functional egg-layers in several species of ponerine ants. In such queenless species, the reproductive status of workers can only be determined through ovarian dissections.

They are most easily identified from other subfamilies by a constricted gaster (abdomen). They are rare examples of stinging ants.


Prochelidella is an extinct genus of Early to Late Cretaceous chelid turtles from the Bajo Barreal, Candeleros, Cerro Barcino and Portezuelo Formations of the Cañadón Asfalto, Golfo San Jorge and Neuquén Basins in Patagonia, Argentina. It includes the following species:

P. argentinae Lapparent de Broin & de la Fuente 2001

P. cerrobarcinae De la Fuente et al. 2011

P. portezuelae De la Fuente 2003


Thalassophonea is an extinct clade of pliosaurids from the Middle Jurassic to the early Late Cretaceous (Callovian - Turonian) of Australia, Europe, North America and South America. Thalassophonea was erected by Roger Benson and Patrick Druckenmiller in 2013. The name is derived from Greek thalassa (θάλασσα), "sea", and phoneus (φονεύς), "murderer". It is a stem-based taxon defined as "all taxa more closely related to Pliosaurus brachydeirus than to Marmornectes candrewi".The following cladogram follows an analysis by Benson & Druckenmiller (2014).


Yaguarasaurus is an extinct genus of mosasauroid from the Late Cretaceous (Turonian) period of Colombia, South America. The remains discovered (an articulated skull, some vertebrae and ribs) were defined as a new genus and species of mosasaurid, Yaguarasaurus columbianus, by the Colombian paleontologist María Páramo, former director of the Museo de Geología José Royo y Gómez of INGEOMINAS in Bogotá. The first fossils remains of this animal suggested a cranial length of 47 centimetres (19 in) and a total length of 5 metres (16 ft); an additional skull that measures 87 centimetres (34 in) long implies a larger size.This reptile is a member of the family of marine lizards Mosasauridae characteristic of Middle and Upper Cretaceous, with global distribution, but in South America known only through isolated remains (Price, 1957, Pierce and Welles, 1959 ; Bonaparte, 1978; Ameghino, 1918). This mosasaur discovered in Yaguará, was at the moment of discovery the most complete material known in South America.


Zuniceratops ('Zuni-horned face') was a ceratopsian dinosaur from the mid Turonian of the Late Cretaceous Period of what is now New Mexico, United States. It lived about 10 million years earlier than the more familiar horned Ceratopsidae and provides an important window on their ancestry.

Cenozoic era
(present–66.0 Mya)
Mesozoic era
(66.0–251.902 Mya)
Paleozoic era
(251.902–541.0 Mya)
Proterozoic eon
(541.0 Mya–2.5 Gya)
Archean eon (2.5–4 Gya)
Hadean eon (4–4.6 Gya)


This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.