Ornithopsis (meaning "bird-likeness") was a medium-sized Early Cretaceous sauropod dinosaur, from England.

Temporal range: Early Cretaceous, 125 Ma
Ornithopsis hulkei lectotype.jpeg
Lectotype vertebra NHMUK R28632
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Sauropodomorpha
Clade: Sauropoda
Clade: Titanosauriformes
Genus: Ornithopsis
Seeley, 1870
O. hulkei
Binomial name
Ornithopsis hulkei
Seeley, 1870

History of discovery

Lectotype dorsal vertebra in anterior view, as illustrated in 1875

The type species, Ornithopsis hulkei, was named and described by Harry Govier Seeley in 1870. The type consisted of two dorsal vertebrae: NHMUK R.2239, found in the Hastings Group of East Sussex, and NHMUK R.28632 found on the Isle of Wight in the Wessex Formation dating from the Barremian. The genus name is derived from Greek ὄρνις (ornis), "bird", en ὄψις (opsis), "face" or "likeness", a reference to the fact that Seeley considered the animal to be an intermediate form bridging the gap between pterosaurs, birds and dinosaurs. The specific name honours John Whitaker Hulke.[1]

Seeley's creation of the genus was, however, not accepted by Richard Owen, who rejected the evolutionary interpretation of the material. Disregarding priority, he therefore in 1875 split it, making NHMUK R2239, that he had in 1841 described as the quadrate of Iguanodon, the holotype of Bothriospondylus elongatus, and making NHMUK R.28632 the holotype of Bothriospondylus magnus.

As a result of the split both vertebrae now went their separate nomenclatural way. BMNH R28632 was in 1876 by Owen made the type of Chondrosteosaurus magnus.[2] John Whitaker Hulke made NHMUK R.28632 the lectotype of O. hulkei, rendering Bothriospondylus magnus a junior objective synonym.[3] By 1882, Hulke grouped all vertebrae of Ornithopsis and Eucamerotus under the new name Ornithopsis eucamerotus along with a set of three pelvic bones (NHMUK R.97, R.97a), and recognized the Bothriospondylus elongatus holotype as being distinct from NHMUK R.28632 in proportion.[4] In 1995 William Blows restricted Ornithopsis to NHMUK R.28632, assigning other vertebrae referred to the genus to Eucamerotus and agreeing with Hulke (1879) the Bothriospondylus elongatus holotype was older than the Ornithopsis lectotype and not conspecific.[5]

Cetiosaurus leedsi anterior caudal
Anterior caudal (NHMUK R1894) of Ornithopsis leedsi

In 1887 Hulke named Ornithopsis leedsii for NHMUK R1984-1988, vertebrae and partial remains of a pelvis found by Alfred Nicholson Leeds near Peterborough.[6] Specimen NHMUK R1984, some vertebrae, was thought to belong to the syntype series but is actually a different individual.[7] This species would be renamed Cetiosaurus leedsi and later Cetiosauriscus leedsii, both today seen as incorrect identifications.

The Ornithopsis hulkei holotype is basically a centrum lacking the neural spine. The vertebra is heavily pneumatised, filled with large cavities, camellae. It is narrow, tall, has a ridge on the underside, is opisthocoelous and has a posteriorly placed deep subtriangular pleurocoel over two thirds of its length. These features are compatible with a placement within the Titanosauriformes.[8]


Ornithopsis hulkei
Referred vertebrae

Ornithopsis is currently restricted to the type species, O. hulkei and the possible second species, O. leedsi, being a nomen dubium and indeterminate beyond Eusauropoda.[9]

  • O. hulkei Seeley 1870 (type)
  • O. eucamerotus Hulke 1882 - nomen dubium
  • O. leedsii Hulke 1887 = Cetiosaurus leedsi (Hulke 1887) Woodward 1905 = Cetiosauriscus leedsii (Hulke 1887) von Huene 1927 = nomen dubium

Misassigned species

  • O. greppini von Huene 1922 = requires its own genus in Eusauropoda


  1. ^ Seeley, H.G., 1870, "Ornithopsis, a gigantic animal of the Pterodacyle kind from the Wealden", Annals and Magazine of Natural History, 4th series 4(5): 305-318
  2. ^ Owen, R. 1876. "Monograph on the fossil Reptilia of the Wealden and Purbeck Formations. Supplement 7. Crocodilia (Poikilopleuron) and Dinosauria? (Chondrosteosaurus)", Palaeontographical Society Monographs 30 : 1-7
  3. ^ Hulke, J. W. (1879). "Note (3rd) on (Eucamerotus, Hulke) Ornithopsis, H. G. Seeley, = Bothrospondylus magnus, Owen, = Chondrosteous magnus, Owen". Quarterly Journal of the Geological Society. 35: 752–762. doi:10.1144/GSL.JGS.1879.035.01-04.55.
  4. ^ Hulke, J. W. (1882). "Note on the Os Pubis and Ischium of Ornithopsis eucamerotus". Quarterly Journal of the Geological Society. 38 (1–4): 372–376. doi:10.1144/GSL.JGS.1882.038.01-04.41.
  5. ^ Blows, W.T. (1995). "The Early Cretaceous brachiosaurid dinosaurs Ornithopsis and Eucamerotus from the Isle of Wight, England" (PDF). Palaeontology. 38 (1): 187–197.
  6. ^ Hulke, J.W. (1887). "Note on some Dinosaurian Remains in the Collection of A. Leeds, Esq. Part I. Ornithopsis leedsii, nov. sp, from the Kimmeridge Clay of Northamptonshire". Geological Magazine. 4 (8): 375–376. doi:10.1017/S0016756800194014.
  7. ^ Noè, L.F., Liston, J.J., and Sandra D. Chapman, 2010, "'Old bones, dry subject': the dinosaurs and pterosaur collected by Alfred Nicholson Leeds of Peterborough, England". In: Moody, R.T.J., Buffetaut, E., Naish, D.W. and Martill, D.M. (eds.) Dinosaurs and Other Extinct Saurians: a Historical Perspective. Series: Geological Society Special Publication (343). The Geological Society, pp. 49-77
  8. ^ * Upchurch, P., Mannion, P. D. & Barrett, P. M. 2011. Sauropod dinosaurs. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 476-525.
  9. ^ ^ Mannion, Philip D.; Upchurch, Paul; Barnes, Rosie N.; Mateus, Octávio (2013). "Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms". Zoological Journal of the Linnean Society. 168: 98-206. doi:10.1111/zoj.12029.
  • Upchurch, P. & Martin, J. 2003. The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England. Journal of Vertebrate Paleontology, 23, 208–231.

External links


Bothriospondylus ("excavated vertebra") is a dubious genus of sauropod dinosaur. It lived during the Late Jurassic.


In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian.


Cetiosauriscus ( SEE-tee-oh-SOR-iss-kəs) is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian (Middle Jurassic Period) in what is now England. A herbivore, Cetiosauriscus had—for sauropod standards—a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. It has been estimated as about 15 m (49 ft) long and between 4 and 10 t (3.9 and 9.8 long tons; 4.4 and 11.0 short tons) in weight.

The only known fossil that was later named Cetiosauriscus includes most of the rear half of a skeleton as well as a hindlimb (NHMUK R3078). Found in Cambridgeshire in the 1890s, it was described by Arthur Smith Woodward in 1905 as a new specimen of the species Cetiosaurus leedsi. This was changed in 1927, when Friedrich von Huene found NHMUK R3078 and the C. leedsi type specimen to be too different from Cetiosaurus, warranting its own genus, which he named Cetiosauriscus, meaning "Cetiosaurus-like". Cetiosauriscus leedsi was referred to the sauropod family Diplodocidae because of similarities in the tail and foot, and had the dubious or intermediate species "Cetiosauriscus" greppini, "C." longus, and "C." glymptonensis assigned to it. In 1980, Alan Charig named a new species of Cetiosauriscus for NHMUK R3078 because of the lack of comparable material to the type of C. leedsi; this species was named Cetiosauriscus stewarti. Because of the poor state of preservation of the Cetiosauriscus leedsi fossil, Charig sent a petition to the International Commission on Zoological Nomenclature to instead make C. stewarti the type species. Cetiosauriscus stewarti became the oldest confirmed diplodocid until a phylogenetic analysis published in 2003 instead found the species to belong to Mamenchisauridae, and followed by studies in 2005 and 2015 that found it outside Neosauropoda, while not a mamenchisaurid proper.

Cetiosauriscus was found in the marine deposits of the Oxford Clay Formation alongside many different invertebrate groups, marine ichthyosaurs, plesiosaurs and crocodylians, a single pterosaur, and various dinosaurs: the ankylosaur Sarcolestes, the stegosaurs Lexovisaurus and Loricatosaurus, the ornithopod Callovosaurus, as well as some unnamed taxa. The theropods Eustreptospondylus, Metriacanthosaurus and Megalosaurus are known from the formation, although probably not from the same level as Cetiosauriscus.


Cetiosaurus () meaning 'whale lizard', from the Greek keteios/κήτειος meaning 'sea monster' (later, 'whale') and sauros/σαυρος meaning 'lizard', is a herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 167 million years ago in what is now Europe and Africa.

Cetiosaurus was in 1842 the first sauropod from which bones were described and is the most complete sauropod found in England. It was so named because its describer, Sir Richard Owen, supposed it was a marine creature, initially an extremely large crocodile, and did not recognise it for a land-dwelling dinosaur. Because of the early description many species would be named in the genus, eventually eighteen of them. Most of these have now been placed in other genera or are understood to be dubious names, based on poor fossil material. The last is true also of the original type species, Cetiosaurus medius, and so C. oxoniensis was officially made the new type species in 2014. C. oxoniensis is based on three more or less complete specimens, discovered from 1868 onwards. Together they contain most of the bones, with the exception of the skull.

Cetiosaurus oxoniensis was a "primitive", quadrupedal, long-necked, small-headed herbivore. It had a shorter tail and neck than most sauropods. The forelimbs on the other hand, were relatively long. C. oxoniensis is estimated to have been about 16 metres (52 ft) long and to have weighed roughly 11 tonnes (12 short tons).

Chimera (paleontology)

In paleontology, a chimera is a fossil that was reconstructed with elements coming from more than a single species (or genus) of animal. A now classic example of chimera is Protoavis.


Chondrosteosaurus (meaning "cartilage and bone lizard") 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. gigas is known only from two neck vertebrae (specimens BMNH 46869, the holotype, and BMNH 46870), with distinctive hollows and internal passages now interpreted as evidence of pneumatic air sacs. Paleontologist Harry Seeley had interpreted similar structures as pneumatic in his specimen of Ornithopsis. Owen disagreed with Seeley's concept of a giant creature bridging the gap between birds or pterosaurs (Owen considered sauropods to be whale-like marine reptiles), and while he acknowledged that the external cavities on the vertebrae may have been connected to the lungs, he interpreted the internal passages as having been filled with cartilage (hence his name for the genus, Chondrosteosaurus or "cartilage and bone lizard").Owen also named a second species, Chondrosteosaurus magnus, that today no longer is considered to belong to Chondrosteosaurus.


Duriatitan is a genus of titanosauriform sauropod dinosaur that lived in the Late Jurassic in what is now England. The holotype specimen of Duriatitan, BMNH 44635, is a partial left upper arm bone which was found by R.I. Smith near Sandsfoot in the lower Kimmeridge Clay from Dorset. The type species, D. humerocristatus, was described in 1874 by John Hulke as a species of Cetiosaurus. The specific name refers to the deltopectoral crest, crista, on the upper arm bone, humerus. The specimen was assigned to its own genus by Paul M. Barrett, Roger B.J. Benson and Paul Upchurch in 2010. The generic name is derived from the Latin name for Dorset, Duria, and Greek Titan.


Eucamerotus (meaning "well-chambered" in reference to the hollows of the vertebrae) was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation (Wealden) of the Isle of Wight, England.


Ferganasaurus was a genus of dinosaur first formally described in 2003 by Alifanov and Averianov. The type species is Ferganasaurus verzilini. It was a sauropod similar to Rhoetosaurus. The fossils were discovered in 1966 in Kyrgyzstan from the Balabansai Formation and date to the Callovian stage of the Middle Jurassic.


Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae.


Gigantosaurus (from the Greek "Γίγας" and "σαυρος", meaning "giant lizard") is a sauropod dinosaur genus from the Late Jurassic Kimmeridge Clay Formation of England. The type species, Gigantosaurus megalonyx, was named and described by Harry Govier Seeley in 1869. Its syntype series consists of several separately discovered sauropod bones found in Cambridgeshire, including two caudal (tail) vertebrae (CAMSM J.29477 and CAMSM J.29478), the distal end of a tibia (CAMSM J.29483), a cast of the right radius (CAMSM J.29482), a cast of phalanx (CAMSM J.29479) and an osteoderm (CAMSM J.29481). It was synonymised to Ornithopsis humerocristatus by Richard Lydekker in 1888 and to Pelorosaurus by Friedrich von Huene in 1909. Today it is considered a nomen dubium.

Because of these references Eberhard Fraas incorrectly assumed in 1908 the name was available for other species and he used it, despite it being preoccupied, for African material totally unrelated to the British finds. As a result, the name Gigantosaurus factored into the convoluted taxonomic history of the African dinosaurs Barosaurus, Tornieria, and Janenschia. A discussion of this can be found in the main Tornieria article.


Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.


Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.


"Ischyrosaurus" (meaning "strong lizard", for its large humerus; name in quotation marks because it is preoccupied) was a genus of sauropod dinosaur from the Kimmeridgian-age Upper Jurassic Kimmeridge Clay of Dorset, England. It was once synonymized with the Early Cretaceous-age Pelorosaurus.


Iuticosaurus (meaning "Jute lizard") 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.

In 1887 Richard Lydekker described two sauropod tail vertebrae found by William D. Fox near Brook Bay on Wight, BMNH R146a and BMNH 151, and referred them to the genus Ornithopsis, despite indicating their similarity to Titanosaurus, because the tail of Ornithopsis was unknown. On reading the paper to the Geological Society of London, Lydekker was criticised by Harry Govier Seeley and John Hulke for his choice and in 1888 he referred to the fossils as Titanosaurus sp. a, Titanosaurus sp. b being a third vertebra, BMNH 32390.In 1929 Friedrich von Huene named both taxa as full species. The first became Titanosaurus Valdensis, the specific name referring to the Wealden, the second Titanosaurus Lydekkeri, its specific name honouring Lydekker. By present convention both specific names would be spelled as T. valdensis and T. lydekkeri respectively.

In 1993 Jean le Loeuff redescribed the material and named a separate genus: Iuticosaurus, the generic name referring to the Jutes who settled the island in the fifth century and established a Jute dynasty in the sixth century. Le Loeuff made Iuticosaurus valdensis the type species, and chose BMNH 151 as the lectotype. Another vertebra, BMNH R 1886, was referred by him to this species. The second species, though formally named by him as Iuticosaurus lydekkeri, he considered a nomen dubium.I. valdensis was found in the Wessex Formation and I. lydekkeri in the younger Upper Greensand.

Iuticosaurus was probably similar to Titanosaurus. It measured 15 to 20 metres (49–65 feet) long.

Most researchers have concluded that I. valdensis cannot be distinguished from other titanosaurs and is therefore a nomen dubium also.

Kellaways Formation

The Kellaways Formation is a geological formation of the Callovian Series from the Jurassic. It is found in the British Isles, immediately above the Great Oolite Series: below the Oxford Clay Formation and above the Cornbrash. It consists of two layers, the Kellaways Sand, a light green-grey clayish silt and sand with layers of sand concretions, overlying the Kellaways Clay, a dark grey plastic fissile clay.They were laid down during the Callovian, offshore from the London-Brabant Island, between 165 and 160 million years ago, in the latitude of the modern Mediterranean Sea, when the structure of Britain was still taking shape. At this stage, the coal swamps of the north-western shore of the island had subsided below the sea so that the Kellaways clay was formed in fairly deep water and the Kellaways sand was blown and washed from what had become the hot desert land.

The holotype of the indeterminate eusauropod "Ornithopsis" leedsii has been recovered from this formation.


Pelorosaurus ( pə-LORR-oh-SOR-əs; meaning "monstrous lizard") is a genus of titanosauriform sauropod dinosaur. Remains referred to Pelorosaurus date from the Early Cretaceous period, about 140-125 million years ago, and have been found in England and Portugal.

The name Pelorosaurus was one of the first to be given to any sauropod. Many species have been assigned to the genus historically, but most are currently considered to belong to other genera. Problematically, the first named species of Pelorosaurus, P. conybeari, is a junior synonym of Cetiosaurus brevis.


Tambatitanis is an extinct genus of titanosauriform dinosaur from the Early Cretaceous (probably early Albian) of Japan. It is known from a single type species, Tambatitanis amicitiae. It was probably around 14 meters long and its mass was estimated at some 4 tonnes. It was a basal titanosauriform and possibly belonged to the Euhelopodidae.


Tornieria ("for Tornier") is a genus of diplodocid sauropod dinosaur from Late Jurassic of Tanzania. It has a convoluted taxonomic history.


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