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.
|Subdivision of the Cretaceous system|
according to the ICS, as of 2017.
The base of the Valanginian is at the first appearance of calpionellid species Calpionellites darderi in the stratigraphic column. A global reference section (a GSSP) had in 2009 not yet been appointed.
The Valanginian is often subdivided in Lower and Upper substages. The Upper substage begins at the first appearance of ammonite species Saynoceras verrucosum and the major marine transgression Va3.
|Birds of the Valanginian|
|Sauropods of the Valanginian|
Bajadasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch (late Berriasian to Valanginian stages) of northern Patagonia, Argentina. It was first described in 2019 based on a single specimen found in 2010 that includes a largely complete skull and parts of the neck. The only species is Bajadasaurus pronuspinax. The genus is classified as a member of the Dicraeosauridae, a group of comparatively small and short-necked sauropods that lived from the Early or Middle Jurassic to the end of the Early Cretaceous.
Bajadasaurus sported bifurcated, extremely elongated neural spines extending from the neck vertebrae. Similar elongated spines are known from the closely related and more completely known Amargasaurus. Various possible functions have been proposed for these spines in Amargasaurus, with the 2019 description of Bajadasaurus suggesting that they could have served as passive defense against predators in both genera. The skull was gracile and equipped with around 44 teeth that were pencil-shaped and restricted to the front of the jaws. The eye openings of Bajadasaurus were exposed in top view of the skull, possibly allowing the animal to look forwards while feeding. Bajadasaurus was discovered in sedimentary rocks of the Bajada Colorada Formation, and its environment resembled a braided river system. It shared its environment with other dinosaurs including the sauropod Leinkupal and different theropods.Berriasian
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.Blackborough End Pit
Blackborough End Pit is a 13.2-hectare (33-acre) geological Site of Special Scientific Interest south-east of King's Lynn in Norfolk. It is a Geological Conservation Review site.This site is important as a demonstration of erosion during the Lower Cretaceous. The Carstone Formation, which dates to the Albian around 110 million years ago, rests unconformably on the Leziate Beds, which date to the Valanginian, over 130 million years ago, and the normally intervening Dersingham Beds are missing.The site is private land with no public access.Brachyphyllum
Brachyphyllum is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They are known from around the globe from the Late Carboniferous to the Late Cretaceous periods.Carcharodontosauridae
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.Craterosaurus
Craterosaurus (meaning krater reptile or bowl reptile) was a genus of stegosaurid dinosaur. It lived during the Early Cretaceous (Valanginian to Barremian stages) around 145-136 million years ago. Its fossils were found in the Woburn Sands Formation of England. Craterosaurus may actually be a junior synonym of Regnosaurus, but only one fossil, a partial vertebra, was recovered.
The type (and only known) species is Craterosaurus pottonensis, described in 1874 by Harry Seeley. The specific name refers to the Potton bonebed. Seeley mistook the fossil, holotype SMC B.28814, for the base of a cranium. Franz Nopcsa in 1912 correctly identified it as the front part of a neural arch. Craterosaurus was placed in Stegosauria by Galton, although subsequent authors did not recognize Craterosaurus as a distinct, valid taxon.Desmoceratidae
Desmoceratidae is a family belonging to the ammonite superfamily Desmoceratoidea. They are an extinct group of ammonoids, shelled cephalopods related to squid, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids, that lived between the Lower Cretaceous (Upper Valanginian) and Upper
Cretaceous (Upper Maastrichtian).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.Hastanectes
Hastanectes is an extinct genus of a plesiosaurian with possible pliosaurid affinities known from the Early Cretaceous Wadhurst Clay Formation (Valanginian stage) of the United Kingdom. It contains a single species, Hastanectes valdensis, which was originally thought to be a species of Cimoliasaurus.Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.Hermit crab
Hermit crabs are decapod crustaceans of the superfamily Paguroidea.Most of the approximately 1,110 species possess an asymmetric abdomen concealed in a scavenged mollusc shell.Hypselospinus
Hypselospinus is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon (I. fittoni) by Richard Lydekker in 1889, the specific name honouring William Henry Fitton.In May 2010 the fossils comprising Hypselospinus were by David Norman reclassified as a separate genus, among them the holotype BMNH R1635, consisting of a left ilium, a sacrum, tail vertebrae and teeth. The generic name is derived from Greek hypselos, "high" and Latin spina, "thorn", in reference to the high vertebral spines. Later that same year, a second group of scientists independently re-classified I. fittoni into a new genus they named Wadhurstia, which thus is a junior objective synonym of Hypselospinus. Hypselospinus lived during the lower Valanginian stage, around 140 million years ago. A contemporary of Barilium (also once thought to be a species of Iguanodon), Hypselospinus was a lightly built iguanodontian estimated at 6 metres (19.7 ft) long. The species Iguanodon fittoni was described from the lower Valanginian-age Lower Cretaceous Wadhurst Clay of East Sussex, England. Remains from Spain may also pertain to it. Norman (2004) wrote that three partial skeletons are known for it, but this is an error.Hypselospinus is separated from Barilium on the basis of vertebral and pelvic characters, size, and build. For example, Barilium was more robust than Hypselospinus, with large Camptosaurus-like vertebrae featuring short neural spines, whereas Hypselospinus is known for its "long, narrow, and steeply inclined neural spines".Leinkupal
Leinkupal is a genus of diplodocine sauropod known from the Early Cretaceous (Late Berriasian to Early Valanginian stage) of the Bajada Colorada Formation, southeastern Neuquén Basin in the Neuquén Province of Argentina. It contains a single species, Leinkupal laticauda.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.Requiem shark
Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas (sometimes of brackish or fresh water) such as the spinner shark, the blacknose shark, the blacktip shark, the grey reef shark, the blacktip reef shark, and the Oceanic whitetip shark.
The name may be related to the French word for shark, requin, which is itself of disputed etymology. One derivation of the latter is from Latin requiem ("rest"), which would thereby create a cyclic etymology (requiem-requin-requiem), but other sources derive it from the verb reschignier ("to grimace while baring teeth").
Family members have the usual carcharhiniform characteristics. Their eyes are round, and one or two gill slits fall over the pectoral fin base. Most species are viviparous, the young being born fully developed. They vary widely in size, from as small as 69 cm (2.26 ft) adult length in the Australian sharpnose shark, up to 5.5 m (18 ft) adult length in the tiger shark.Requiem sharks are involved in a large proportion of attacks on humans, among the top five species; however, due to the difficulty in identifying individual species, a degree of inaccuracy exists in attack records.Rosablanca Formation
The Rosablanca Formation (Spanish: Formación Rosablanca, Kir) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes and the Middle Magdalena Basin. The formation consists of grey limestones, dolomites and shales with at the upper part sandstones. The formation dates to the Early Cretaceous period; Valanginian epoch and has a thickness of 425 metres (1,394 ft) in the valley of the Sogamoso River.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.
(541.0 Mya–2.5 Gya)
|Archean eon (2.5–4 Gya)|
|Hadean eon (4–4.6 Gya)|