Valdosaurus
Encyclopedia
Valdosaurus is a genus
of biped
al herbivorous iguanodont
ornithopod
dinosaur
found on the Isle of Wight
and elsewhere in England
. It lived during the Early Cretaceous
.
collected two small thighbones near Cowleaze Chine
on the southwest coast of the Isle of Wight. In 1868 he incorrectly suggested these may have come from the same individual that had in 1848 been uncovered for Gideon Mantell
as a fossil of Iguanodon
, and which in 1869 would be named as the new genus Hypsilophodon
. Regardless, both femora, made part of the collection of the British Museum of Natural History as specimens BMNH R184 and BMNH R185, would be commonly referred to the latter genus.
However, in 1975 Peter Galton
named them as a new species of Dryosaurus
: Dryosaurus canaliculatus. The specific name means "with a small channel" in Latin
, referring to a distinct groove between the condyles of the lower thighbone. In 1977 Galton named a new genus for them: Valdosaurus, the name being derived from Latin Valdus, "Wealden
", a reference to the Wealden Group
. Its type species
, D. canaliculatus, was thus renamed V. canaliculatus. A second species, V. nigeriensis, was described by Galton and Philippe Taquet
from younger rocks from Niger
in 1982; this has since been transferred to its own genus, Elrhazosaurus
.
In 1998 William Blows inadvertently named another species, Valdosaurus dextrapoda, by including this name in a fauna list, but this was an error, and the species has never been supported. Lacking description, it is a nomen nudum
.
(the Wessex Formation
of the Isle of Wight
and the Hastings Beds
of West Sussex
) but also in Romania
(the Cornet Bauxite of Bihor
) and Spain
. These rock units were deposited between the Berriasian
and Barremian
stages, between approximately 145 and 125 million years ago. V. canaliculatus would then be known from thigh bones
, extensive additional postcrania
l elements, partial lower jaws, and teeth.
In 2009 however, Galton critically reviewed the Valdosaurus material. He concluded that no fossils from outside of England could be reliably referred to the genus. He thus gave V. nigeriensis its own genus: Elrhazosaurus
. Even of many of the English specimens it was uncertain whether they belonged to Valdosaurus, including all cranial elements and teeth. Some hindlimb and pelvis bones from the Upper Wealden Clay Formation (late Barremian) were referable to V. canaliculatus. Some material from the earlier Hastings Beds (Valanginian
) were referred to a Valdosaurus sp. Galton established that Richard Owen
had in 1842 been the first to describe Valdosaurus thighbones, specimens BMB 004297-004300, assigning them to Iguanodon. Galton emphasized that though the type femora were very small, fourteen centimetres long (which has led to estimates of a length of 1.2 metres and a weight of ten kilograms), these were from a juvenile individual and that an adult would have been a "medium-sized euornithopod", with some thighbones reaching a length of half a metre.
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of biped
Biped
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs, or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning "two feet"...
al herbivorous iguanodont
Iguanodont
Iguanodonts were herbivorous dinosaurs that lived from the mid-Jurassic to Late Cretaceous. Some members include Camptosaurus, Callovosaurus, Iguanodon, Ouranosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodonts were one of the first groups of dinosaurs to be found...
ornithopod
Ornithopod
Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American...
dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
found on the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
and elsewhere in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. It lived during 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...
.
Discovery and naming
In the nineteenth century Reverend William Darwin FoxWilliam Darwin Fox
The Reverend William Darwin Fox was an English clergyman, naturalist, and a 2nd cousin of Charles Robert Darwin.- Early life :...
collected two small thighbones near Cowleaze Chine
Cowleaze Chine
Cowleaze Chine is a geological feature on the south west coast of the Isle of Wight, England. It lies to the west of the village of Little Atherfield.This chine is just to the west of the larger Shepherd's Chine...
on the southwest coast of the Isle of Wight. In 1868 he incorrectly suggested these may have come from the same individual that had in 1848 been uncovered for Gideon Mantell
Gideon Mantell
Gideon Algernon Mantell MRCS FRS was an English obstetrician, geologist and palaeontologist...
as a fossil of 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...
, and which in 1869 would be named as the new genus 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...
. Regardless, both femora, made part of the collection of the British Museum of Natural History as specimens BMNH R184 and BMNH R185, would be commonly referred to the latter genus.
However, in 1975 Peter Galton
Peter Galton
Peter M. Galton is a British vertebrate paleontologist working in America, who has to date written or co-written about a hundred papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosauropod dinosaurs.With Robert Bakker in a joint article...
named them as a new species of Dryosaurus
Dryosaurus
Dryosaurus is a genus of an ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont . Fossils have been found in the western United States, and were first discovered in the late 19th century...
: Dryosaurus canaliculatus. The specific name means "with a small channel" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, referring to a distinct groove between the condyles of the lower thighbone. In 1977 Galton named a new genus for them: Valdosaurus, the name being derived from Latin Valdus, "Wealden
Wealden
For the stone, see Wealden GroupWealden is a local government district in East Sussex, England: its name comes from the Weald, the area of high land which occupies the centre of its area.-History:...
", a reference to 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...
. Its type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
, D. canaliculatus, was thus renamed V. canaliculatus. A second species, V. nigeriensis, was described by Galton and Philippe Taquet
Philippe Taquet
Philippe Taquet is a French paleontologist who specializes in dinosaur systematics of finds primarily in northern Africa.He is a member of the French Academy of Sciences since November 30, 2004...
from younger rocks from Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
in 1982; this has since been transferred to its own genus, Elrhazosaurus
Elrhazosaurus
Elrhazosaurus is a genus of basal iguanodontian dinosaur, known from isolated bones found in Lower Cretaceous rocks of Niger. These bones were initially thought to belong to a species of the related dryosaurid Valdosaurus, but have since been reclassified.-Discovery and history:Elrhazosaurus is...
.
In 1998 William Blows inadvertently named another species, Valdosaurus dextrapoda, by including this name in a fauna list, but this was an error, and the species has never been supported. Lacking description, it is a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
.
Distribution and material
Having a close European relative of the American form Dryosaurus named led to most of the dryosaurid fossil material of Europe being referred to Valdosaurus. Valdosaurus was seen as not only present in EnglandEngland
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
(the Wessex Formation
Wessex Formation
The Wessex Formation is an English fossil site and geological formation that dates to the Barremian stage of the Early Cretaceous. It is part of the Wealden Group and underlies the younger Vectis Formation.-Invertebrates:...
of the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
and the Hastings Beds
Hastings Beds
The Hastings Beds is a geological formation in southeast England whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Ornithischians:-Saurischians:-References:...
of West Sussex
West Sussex
West Sussex is a county in the south of England, bordering onto East Sussex , Hampshire and Surrey. The county of Sussex has been divided into East and West since the 12th century, and obtained separate county councils in 1888, but it remained a single ceremonial county until 1974 and the coming...
) but also in Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
(the Cornet Bauxite of Bihor
Bihor County
Bihor is a county of Romania, in Crişana, with capital city at Oradea. Together with Hajdú-Bihar County in Hungary it constitutes the Biharia Euroregion.-Demographics:...
) and Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. These rock units were deposited between the Berriasian
Berriasian
In the geological timescale, the Berriasian is an age or stage of the Early or Lower Creteceous. It is the oldest or lowest subdivision in the entire Cretaceous. It spanned between 145.5 ± 4.0 Ma and 140.2 ± 3.0 Ma...
and 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...
stages, between approximately 145 and 125 million years ago. V. canaliculatus would then be known from thigh bones
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
, extensive additional postcrania
Postcrania
Postcrania[p] in zoology and vertebrate paleontology refers to all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g...
l elements, partial lower jaws, and teeth.
In 2009 however, Galton critically reviewed the Valdosaurus material. He concluded that no fossils from outside of England could be reliably referred to the genus. He thus gave V. nigeriensis its own genus: Elrhazosaurus
Elrhazosaurus
Elrhazosaurus is a genus of basal iguanodontian dinosaur, known from isolated bones found in Lower Cretaceous rocks of Niger. These bones were initially thought to belong to a species of the related dryosaurid Valdosaurus, but have since been reclassified.-Discovery and history:Elrhazosaurus is...
. Even of many of the English specimens it was uncertain whether they belonged to Valdosaurus, including all cranial elements and teeth. Some hindlimb and pelvis bones from the Upper Wealden Clay Formation (late Barremian) were referable to V. canaliculatus. Some material from the earlier Hastings Beds (Valanginian
Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 140.2 ± 3.0 Ma and 136.4 ± 2.0 Ma...
) were referred to a Valdosaurus sp. Galton established that Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
had in 1842 been the first to describe Valdosaurus thighbones, specimens BMB 004297-004300, assigning them to Iguanodon. Galton emphasized that though the type femora were very small, fourteen centimetres long (which has led to estimates of a length of 1.2 metres and a weight of ten kilograms), these were from a juvenile individual and that an adult would have been a "medium-sized euornithopod", with some thighbones reaching a length of half a metre.
Phylogeny
Galton assigned Valdosaurus to the Hypsilophodontidae, but this paraphyletic unnatural group has largely been abandoned. Today Valdosaurus is generally considered a member of the DryosauridaeDryosauridae
Dryosaurids were primitive iguanodonts. They are known from Middle Jurassic to Early Cretaceous rocks of Africa, Europe, and North America.-Phylogeny:...
.