In the geological timescale, the Berriasian is an age or stage of the Early Cretaceous. It is the oldest, or lowest, subdivision in the entire Cretaceous. It spanned the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian.
|Subdivision of the Cretaceous system|
according to the ICS, as of 2017.
The Berriasian Stage was introduced in scientific literature by Henri Coquand in 1869. It is named after the village of Berrias in the Ardèche department of France. The largely non-marine English Purbeck Formation is in part of Berriasian age. In fact, the first rocks to be described of this age were the beds of the English Purbeck Formation, named as the Purbeckian by Alexandre Brongniart in 1829 following description by Henry De la Beche, William Buckland, Thomas Webster and William Henry Fitton.
The base of the Berriasian, which is also the base of the Cretaceous system, has traditionally been placed at the first appearance of fossils of the ammonite species Berriasella jacobi. But this is a species that has a stratigraphically problematic and geographically limited distribution. A global reference profile (a GSSP) for the Berriasian has been under active consideration by the International Subcommission on Cretaceous Stratigraphy (ISCS) of IUGS. A range of contender GSSP localities has been studied in detail by the ISCS's Berriasian Working Group including localities as far apart as Mexico, Ukraine, Tunisia, Iraq and the Russian Far East. Several markers have been employed to refine correlations and to work towards defining a base for the Berriasian Stage. These include calcareous nannofossils, such as Nannoconus, calpionellids, ammonites, palynological data and magnetostratigraphy, notably magnetozone M19n. The calibration of these markers, especially Nannoconus steinmannii minor, N. kamptneri minor, and Calpionella alpina, within precisely fixed magnetozones give greater precision in trying to identify the best position for a boundary. In June 2016, the Berriasian Working Group voted to adopt Calpionella alpina as the primary marker for the base of the Berriasian Stage.
The top of the Berriasian stage is defined by the base of the Valanginian, which is fixed at the first appearance of calpionellid species Calpionellites darderi. This is just a little below the first appearance of the ammonite species Thurmanniceras pertransiens.
|Birds of the Berriasian|
|Mammals of the Berriasian|
|Durlston Bay, Dorset, England|
|Durlston Bay, Dorset, England; Spain|
|Durlston Bay, Dorset, England|
The Arcabuco Formation (Spanish: Formación Arcabuco, Jar, JKa) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of thick beds of light-coloured quartzitic sandstones and conglomerates with occasional shales and dates to the Late Jurassic and Early Cretaceous periods; Tithonian to Berriasian epochs. Dinosaur footprints have been found in the Arcabuco Formation near the Iguaque anticlinal outside Chíquiza, Boyacá.Azhdarchidae
Azhdarchidae (from Persian word azhdar (اژدر), a serpentine creature equivalent to a dragon in Persian mythology) is a family of pterosaurs known primarily from the late Cretaceous Period, though an isolated vertebra apparently from an azhdarchid is known from the early Cretaceous as well (late Berriasian age, about 140 million years ago). Azhdarchids included some of the largest-known flying animals of all time, but members no larger than a cat have also been found. Originally considered a sub-family of Pteranodontidae, Nesov (1984) named the azhdarchinae to include the pterosaurs Azhdarcho, Quetzalcoatlus, and "Titanopteryx" (now known as Arambourgiania). They were among the last known surviving members of the pterosaurs, and were a rather successful group with a worldwide distribution. By the time of the end-Cretaceous mass extinction, most pterosaur families except for the Azhdarchidae disappear from the fossil record, but recent studies indicate a wealth in pterosaurian faunas, including pteranodontids, nyctosaurids, tapejarids and several indeterminate forms. Some taxa like Navajodactylus, Bakonydraco and Montanazhdarcho were moved from Azhdarchidae to other clades.Baños del Flaco Formation
The Baños del Flaco Formation is a Late Jurassic to Early Cretaceous (Tithonian to Berriasian geologic formation in central Chile. The formation comprises limestones and sandstones deposited in a shallow marine to fluvial environment. Fossil ornithopod tracks have been reported from the formation.Camarasauridae
Camarasauridae (meaning "chambered lizards") is a family of neosauropod dinosaurs within the clade Macronaria, the sister group to Titanosauriformes. Among sauropods, camarasaurids are small to medium-sized, with relatively short necks. They are visually identifiable by a short skull with large nares, and broad, spatulate teeth filling a thick jaw. Based on cervical vertebrae and cervical rib biomechanics, camarasaurids most likely moved their necks in a vertical, rather than horizontal, sweeping motion, in contrast to most diplodocids. Cladistically, they are defined to be all sauropods more closely related to Camarasaurus supremus than to Saltasaurus loricatus.Caypullisaurus
Caypullisaurus is an extinct genus of large platypterygiine ophthalmosaurid ichthyosaur from the Late Jurassic to the Early Cretaceous (Tithonian and Berriasian stages) of Argentina. Its holotype was collected from the Vaca Muerta Formation of Cerro Lotena, Neuquen, dating to the early Tithonian stage of the Late Jurassic, about 150 million years ago. Caypullisaurus was first named by Marta Fernández in 1997 and the type species is Caypullisaurus bonapartei. It is a member of the family Ophthalmosauridae, and closely related to Platypterygius and Brachypterygius. In 2012, Caypullisaurus was found to be most closely related to Athabascasaurus and "Platypterygius" australis, and to nest within the subfamily Platypterygiinae.Cryptoclididae
Cryptoclididae is a family of medium-sized plesiosaurs that existed from the middle Jurassic to the early Cretaceous period. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and crustaceans.Goniopholididae
Goniopholididae is an extinct family of moderate-sized semi-aquatic crocodyliforms superficially similar to living crocodiles (but see below). They lived between the Early Jurassic and the Late Cretaceous.Guavio Formation
The Guavio Formation (Spanish: Calizas del Guavio, Kicg) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of conglomerates, shales and limestones, dates to the Late Jurassic and Early Cretaceous periods; Tithonian to Berriasian epochs and has a maximum thickness of 1,000 metres (3,300 ft).Leptocleididae
Leptocleididae is a family of small-sized plesiosaurs that lived during the Early Cretaceous period (early Berriasian to early Albian stage). Leptocleidus and Umoonasaurus had round bodies and triangle-shaped heads. Hilary F. Ketchum and Roger B. J. Benson (2010), transferred Brancasaurus, Kaiwhekea, Nichollssaura and Thililua to this family. However, Ketchum and Benson (2011) reassigned Kaiwhekea and Thililua to their original positions, as an elasmosaurid and a polycotylid, respectively.Nodosauridae
Nodosauridae is a family of ankylosaurian dinosaurs, from the Late Jurassic to the Late Cretaceous period of what are now North America, Europe, Asia, Africa, and Antarctica.Pholidosauridae
Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe (Denmark, England, France, Germany, Spain and Sweden), Africa (Algeria, Niger, Mali, Morocco and Tunisia), North America (Canada and the United States) and South America (Brazil and Uruguay). The pholidosaurids first appeared in the fossil record during the Bathonian stage of the Middle Jurassic and became extinct during the Late Turonian stage of the Late Cretaceous.Sarcosuchus is one of the best known pholidosaurs. It is believed to have attained lengths of up to 12 metres (39 ft 4 in) and weighed up to 8 tonnes (7.9 long tons; 8.8 short tons). One genus, Suchosaurus, once thought to be a pholidosaur, has since been shown to be a spinosaurid theropod dinosaur.Protosuchidae
Protosuchidae was a family of crocodylmorph reptiles from the Late Triassic, Jurassic, and Cretaceous time periods. They were closely related to the Gobiosuchidae.Purbeck Group
The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in the cliffs west of Swanage.
The Purbeck Group is famous for its fossils of reptiles and early mammals. This sequence of rocks has gone by various names in the past including amongst others the Purbeck Beds, Purbeck Formation, Purbeck Limestone Formation and Purbeck Stone.Rocks of this age have in the past been called the Purbeckian stage by European geologists. The Purbeckian corresponds with the Tithonian to Berriasian stages of the internationally used geologic timescale.Shartegosuchidae
Shartegosuchidae is an extinct family of Late Jurassic and Early Cretaceous crocodylomorphs. The family is named after the Late Jurassic Shar Teeg Beds in southwestern Mongolia, from which most shartegosuchid remains have been found. Five genera are currently assigned to Shartegosuchidae: Shartegosuchus, Nominosuchus, Kyasuchus, Adzhosuchus, and Fruitachampsa. Shartegosuchus, Nominosuchus, and Adzhosuchus all come from Shar Teeg, while Kyasuchus is known from the Early Cretaceous of Russia. Fruitachampsa is known from the Late Jurassic Morrison Formation of the western United States.Teleosauridae
The teleosaurids were marine crocodyliforms similar to the modern gharial that lived from the Early Jurassic to the Early Cretaceous. They had long snouts, indicative of piscivory (fish eating) and were the closest relatives to the Metriorhynchidae, the Mesozoic crocodilians that returned to the sea and evolved paddle-like forelimbs and a shark-like tail.Tithonian
In the geological timescale, the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. It spans the time between 152.1 ± 4 Ma and 145.0 ± 4 Ma (million years ago). It is preceded by the Kimmeridgian and followed by the Berriasian stage (part of the Cretaceous).Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian stage succeeds the Berriasian stage of the Lower Cretaceous and precedes the Hauterivian stage of the Lower Cretaceous.Wealden Group
The Wealden Group is a group (a sequence of rock strata) in the lithostratigraphy of southern England. The Wealden group consists of paralic to continental (freshwater) facies sedimentary rocks of Berriasian to Aptian age and thus forms part of the English Lower Cretaceous. It is composed of alternating sands and clays. The sandy units were deposited in a flood plain of braided rivers, the clays mostly in a lagoonal coastal plain.The Wealden Group can be found in almost all Early Cretaceous basins of England: its outcrops curve from the Wessex Basin in the south to the Cleveland Basin in the northeast. It is not found in northwest England and Wales, areas which were at the time tectonic highs where no deposition took place. The same is true for the London Platform around London and Essex. Offshore, the Wealden Group can reach a thickness of 700 metres.Zapata Formation
Zapata Formation (Spanish: Formación Zapata) is a sedimentary formation of Lower Cretaceous age in the Magallanes or Austral Basin of Argentina and Chile. Much of the formation is folded and faulted as consequence of the Andean orogeny. In outcrops of the Zapata Formation near Torres del Paine, the southernmost fossil of the ichthyosaur genus Platypterygius has been found.
(541.0 Mya–2.5 Gya)
|Archean eon (2.5–4 Gya)|
|Hadean eon (4–4.6 Gya)|