Wessex Formation - AbsoluteAstronomy.com

The Wessex Formation is an English fossil site and geological formation that dates to the Barremian

Barremian

The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...

stage (about 130 million years ago) of the Early Cretaceous

Early Cretaceous

The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

. It is part of the Wealden Group

Wealden Group

The Wealden Group is a group in the lithostratigraphy of southern England. The Wealden group consists of paralic to continental facies sedimentary rocks of Valanginian to Barremian age and thus forms part of the English Lower Cretaceous. It is composed of alternating sands and clays...

and underlies the younger Vectis Formation

Vectis Formation

The Vectis Formation is a geological formation on the Isle of Wight, England whose strata date back to the Early Cretaceous . The Vectis Formation is composed of three geological members: the Shepherds Chine member, the Barnes High Sandstone member, and the Cowleaze Chine member...

Invertebrates

Invertebrate

An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s are commonly preserved in the Wessex Formation. Freshwater bivalves can be found including unionoids

Unionoida

Unionoida is an order of freshwater mussels, aquatic bivalve mollusks. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels...

such as Margaritifera

Margaritifera

Margaritifera is a genus of freshwater mussels, aquatic bivalve molluscs in the family Margaritiferidae, the freshwater pearl mussels.-Species:Species within the genus Margaritifera include:...

, Nippononaia, and Unio

Unio

Unio can refer to:* Unio, a genus in the family Unionidae * UNIO Satu Mare, machine building company from Romania* Utdanningsgruppenes Hovedorganisasjon , a national trade union center in Norway....

. These bivalves are helpful in reconstructing what the freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

paleoenvironment

Paleoecology

Paleoecology uses data from fossils and subfossils to reconstruct the ecosystems of the past. It involves the study of fossil organisms and their associated remains, including their life cycle, living interactions, natural environment, and manner of death and burial to reconstruct the...

may have been like during the formation's deposition. Specimens of Viviparus

Viviparus

Viviparus, common name river snails, is a genus of large, freshwater snails with an operculum, aquatic gastropod mollusks. They are primitive members of the superorder Caenogastropoda.-Distribution:This genus is palaearctic in distribution....

, a genus of freshwater snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

, have also been found. Cretamygale chasei, a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

of Mygalomorph

Mygalomorphae

The Mygalomorphae, , are an infraorder of spiders. The latter name comes from the orientation of the fangs which point straight down and do not cross each other .-Description:...

spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

, has been described from a specimen found in amber

Amber

Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...

. It is believed to be the oldest known Nemesiid

Nemesiidae

The Nemesiidae are a spider family of the infraorder Mygalomorphae, and the only member of the superfamily Nemesioidea. They were formerly considered part of the Dipluridae family.-Description:...

and the second oldest Mygalomorph.

Cartilaginous fishes

Cartilaginous fishes of the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Hybodus Hybodus Hybodus is an extinct genus of once-common, widespread and long lived sharks, first appearing towards the end of the Permian period, and disappearing at the beginning of the Cretaceous. During the Triassic, Jurassic, and Cretaceous periods the hybodonts were especially successful and could be...	H. basanus
Hylaeobatis	H. problematica
Palaeoscyllium	Indeterminate
Vectiselachos	V. ornatus

Ray-finned fish

Ray-finned fishes of the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Caturus	Indeterminate
Coelodus Coelodus Coelodus is an extinct genus of prehistoric bony fish.-See also:* Prehistoric fish* List of prehistoric bony fish...	Indeterminate
Lepidotes Lepidotes Lepidotes is an extinct genus of neopterygian ray-finned fish from the Jurassic and Cretaceous periods. Fossils have been found worldwide....	Indeterminate

Turtles

Turtles of the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Abundance	Notes
Helochelydra	H. anglica
Plesiochelys	P. planiceps
Tretosternum	T. ambiguum

Crurotarsans

Crurotarsans of the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Bernissartia Bernissartia Bernissartia is an extinct genus of crocodyliform that lived in the Early Cretaceous, around 130 million years ago.At only in length, Bernissartia is one of the smallest crocodyliforms that ever lived. It resembled modern species in many respects, and was probably semi-aquatic...	B. fagesii
Goniopholis Goniopholis Goniopholis is an extinct genus of crocodyliform that lived in North America, Europe and Asia during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles...	G. cressidens
Oweniasuchus Oweniasuchus Oweniasuchus is an extinct genus of goniopholidid mesoeucrocodylian. Remains have been found from England and Portugal that are Cretaceous in age....	Indeterminate
Pholidosaurus Pholidosaurus Pholidosaurus is an extinct genus of neosuchian crocodylomorph. It is the type genus of the family Pholidosauridae. Fossils have been found from Germany and England. The genus is known to have existed during the Berriasian stage of the Early Cretaceous...	P. meyeri
Theriosuchus Theriosuchus Theriosuchus is an extinct genus of atoposaurid mesoeucrocodylian from the Late Jurassic of Europe, the Early Cretaceous of Asia and the Late Cretaceous of Romania. The five species are T. pusillus from England , T. ibericus from Spain , T. guimarotae from Portugal , T. sympiestodon from Romania...	Indeterminate
Vectisuchus Vectisuchus Vectisuchus is a genus of goniopholidid mesoeucrocodylian, known from the Early Cretaceous-age Wealden Group of the Isle of Wight, England. It was a small, piscivorous crocodylomorph with a narrow, elongate snout, and relatively long forearms. The type specimen, SMNS 50984, was found in 1977...	V. leptognathus

Pterosaurs

Pterosaurs of the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Abundance	Notes	Images
Caulkicephalus Caulkicephalus Caulkicephalus is a genus of pterosaur, belonging to the Pterodactyloidea, from the Isle of Wight off the coast of England.Between 1995 and 2003 bone fragments of an unknown pterosaur were found at the Yaverland locality near Sandown...	C. trimicrodon
Istiodactylus Istiodactylus Istiodactylus was a medium sized pterosaur from the Early Cretaceous period.-History and species:In 1887 Harry Govier Seeley named the remains of a fossil pelvis discovered on the Isle of Wight, Ornithodesmus cluniculus, thinking it was a bird. In 1901 he considered that it might have been a...	I. latidens
Ornithocheirus Ornithocheirus Ornithocheirus was a pterosaur from the Cretaceous period of Europe and South America...	Indeterminate

Ornithischians

Ornithischians reported from the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Dollodon Dollodon Dollodon is a genus of ornithopod dinosaur that lived in the Barremian and possibly the early Aptian ages of the Early Cretaceous Period of Europe. Its remains are known from Belgium , England and possibly Germany...	D. seelyi
Hypsilophodon Hypsilophodon Hypsilophodon is an ornithopod dinosaur genus from the Early Cretaceous period of Europe. It was a small bipedal animal with an herbivorous or possibly omnivorous diet...	H. foxii
Iguanodon Iguanodon Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...	I. atherfieldensis				Reclassified as Dollodon seelyi or Mantellisaurus atherfieldensis
	I. seelyi				Reclassified as Dollodon seelyi
	I. bernissartensis				Specimens classified as Dollodon seelyi were sometimes considered to belong to this species
Polacanthoides	P. ponderosus			"Tibia."
Polacanthus Polacanthus Polacanthus, deriving its name from the Ancient Greek poly-/πολυ- "many" and acantha/ακανθα "thorn" or "prickle", was an early armored, spiked, plant-eating ankylosaur from the early Cretaceous period. Early depictions often gave it a very vague head as it was only known from the rear half of the...	P. foxii
	P. rudgwickensis
Regnosaurus Regnosaurus Regnosaurus is a genus of herbivorous stegosaurian dinosaur that lived during the Early Cretaceous Period in what is now England.-Discovery and species:...	R. northamptoni			"Partial dentary, pubis, osteoderms."
Valdosaurus Valdosaurus Valdosaurus is a genus of bipedal herbivorous iguanodont ornithopod dinosaur found on the Isle of Wight and elsewhere in England. It lived during the Early Cretaceous.-Discovery and naming:...	V. canaliculatus
Yaverlandia Yaverlandia Yaverlandia is a genus of theropod dinosaur. Known from a partial fossil skull found in Lower Cretaceous strata on the Isle of Wight, it was described as the earliest known member of the pachycephalosaurid family, but recent research by Darren Naish shows it to have actually been a theropod,...	Y. bitholus			"Skull fragment."

Sauropods

Indeterminate diplodicoid and rebbachisaurid remains are known from the formation.

Sauropods reported from the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
"Angloposeidon Angloposeidon "Angloposeidon" is the informal name given to a dinosaur from the Early Cretaceous of southern England. It was a possible brachiosaurid but has not been formally named. Darren Naish, a notable vertebrate palaeontologist, has worked with the specimen and has recommended that this name only be used... "
Bothriospondylus Bothriospondylus Bothriospondylus is an dubious genus of sauropod dinosaur. It lived during the Late Jurassic.The type species, Bothriospondylus suffossus, was described by Richard Owen in 1875. The specific epithet suffossus means "undermined" in Latin, a reference to the fact that pleurocoels had hollowed out...	B. magnus			"Vertebra."
Chondrosteosaurus Chondrosteosaurus Chondrosteosaurus was a sauropod from Early Cretaceous England.The type species, Chondrosteosaurus gigas, was described and named by Richard Owen in 1876. The fossils of Chondrosteosaurus were discovered in the Wessex Formation on the Isle of Wight. C...	C. gigas			"Several cervical vertebrae."
Eucamerotus Eucamerotus Eucamerotus was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is known from vertebral remains, and a partial skeleton has been referred, although this has not been accepted...	E. foxi			"Dorsal vertebra."
Iuticosaurus Iuticosaurus Iuticosaurus is the name given to a genus of dinosaur from the Early Cretaceous of the Isle of Wight. Iuticosaurus was a sauropod, specifically a titanosaur....	I. valdensis
Oplosaurus Oplosaurus Oplosaurus was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England...	O. armatus			"Tooth."
Ornithopsis Ornithopsis Ornithopsis was a medium-sized Early Cretaceous sauropod dinosaur, from England. It has been considered a synonym of the wastebasket taxon Pelorosaurus, but recent research suggests that this is not as clear-cut as supposed...	O. eucamerotus			"Ischia and pubis."
	O. hulkei			"[Two] dorsal vertebrae."
Pelorosaurus Pelorosaurus Pelorosaurus was a huge plant-eating dinosaur. Pelorosaurus was one of the first sauropod dinosaurs ever discovered. Pelorosaurus lived during the Early Cretaceous period, about 138-112 million years ago. Fossils referred to Pelorosaurus have been found in England and Portugal...	P. humerocristatus
Pleurocoelus	P. altus
Pleurocoelus	P. valdensis			"Vertebrae and teeth."
Titanosaurus Titanosaurus Titanosaurus is a genus of sauropod dinosaur, first described by Lydekker in 1877. It is known from the Maastrichtian Lameta Formation of India...	T. lydekkeri			"Caudal vertebra."
	T. valdensis			"Several caudal vertebrae."

Theropods

Indeterminate velociraptorine remains have been recovered from the Wessex Formation.

Theropods reported from the Wessex Formation
Genus	Species	Location	Stratigraphic Position	Material	Notes	Images
Altispinax Altispinax Altispinax is a genus of theropod dinosaur from the Early Cretaceous Obernkirchen Sandstein of Niedersachsen, Germany. Material has also been referred to it from the Hastings Beds , Purbeck Beds , and Lower Greensand of England, and the Weald Clay of England and Belgium, but this material...	A. dunkeri			"Isolated teeth."
Aristosuchus Aristosuchus Aristosuchus was a small coelurosaurian dinosaur, whose name was derived from the Greek ἄριστος and σουχος, the Ancient Greek corruption of the name of the Egyptian crocodile-headed god Sobek. It shared many characteristics with birds.Aristosuchus was a bipedal, meat-eating theropod dinosaur...	A. pussilis			"Sacrum and pubes."
Baryonyx Baryonyx Baryonyx is a genus of carnivorous saurischian dinosaur first discovered in clay pits just south of Dorking, England, and later reported from fossils found in northern Spain and Portugal. It is known to contain only one species, Baryonyx walkeri...	B. walkeri				A spinosaurid possibly synonymous with Suchosaurus cultridens
Calamosaurus Calamosaurus Calamosaurus was a genus of small theropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England...	C. foxi			"Vertebrae."
	C. oweni			"Vertebrae, pubes, phalanx."
Calamospondylus Calamospondylus Calamospondylus was a theropod dinosaur genus. It lived during the Early Cretaceous, and its fossils were found in England. The type species, Calamospondylus oweni, was described by amateur paleontologist Reverend William D. Fox in 1866, but is based on fragmentary material...	C. oweni			"Vertebrae."
Eotyrannus Eotyrannus Eotyrannus was a genus of tyrannosauroid theropod dinosaur hailing from the Early Cretaceous Wessex Formation beds, included in Wealden Group, located in the southwest coast of the Isle of Wight, United Kingdom...	E. lengi			"Partial skull and skeleton."
Neovenator Neovenator Neovenator is a genus of allosauroid dinosaur. Since its discovery on the Isle of Wight, UK, it has become one of the best-known large carnivorous dinosaurs in Europe. Neovenator was at first considered possibly a new species of Megalosaurus. It measured approximately 7.5 meters in length,...	N. salerii			"Partial skull and skeleton."
Ornithodesmus Ornithodesmus Ornithodesmus is a genus of small, deinonychosaurian dinosaur from the Isle of Wight in England, dating to about 125 million years ago. The name was originally assigned to a bird-like sacrum , initially believed to come from a pterosaur...	O. cluniculus				A dromaeosaurid
Suchosaurus Suchosaurus Suchosaurus is as a spinosaurid theropod dinosaur from Cretaceous England, originally believed to be a genus of crocodile. The type material consists of teeth. Two species, S. cultridens and S. girardi have been named, though the S. girardi material was reclassified by Buffetaut as Baryonyx...	S. cultridens				A spinosaurid
Thecocoelurus Thecocoelurus Thecocoelurus is a genus of theropod dinosaur from the early Cretaceous period of England.Thecocoelurus is known only from half of a single cervical vertebra, discovered by the Rev. William Darwin Fox on the Isle of Wight during the 19th century. After his death the Fox Collection was acquired by...	T. daviesi			"Cervical vertebrae."
Thecospondylus Thecospondylus Thecospondylus is a dubious genus of dinosaur from the Early Cretaceous of EnglandDr. A.C. Horner, an amateur geologist living at Tonbridge, in the nineteenth century acquired a fossil found in the quarry of Southborough...	T. daviesi			"Cervical vertebrae."
Yaverlandia Yaverlandia Yaverlandia is a genus of theropod dinosaur. Known from a partial fossil skull found in Lower Cretaceous strata on the Isle of Wight, it was described as the earliest known member of the pachycephalosaurid family, but recent research by Darren Naish shows it to have actually been a theropod,...	Y. bitholus

External links

Discovery of shark teeth

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