Ornithopsis

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Ornithopsis
Temporal range:
Early Cretaceous, Barremian
↓
Lectotype vertebra NHMUK R28632
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: †Sauropodomorpha
Clade: †Sauropoda
Clade: †Macronaria
Clade: †
Titanosauriformes
Genus: †Ornithopsis
Seeley, 1870[1]
Species:
†O. hulkei
Binomial name
†Ornithopsis hulkei
Seeley, 1870[1]
Synonyms[4]
  • Bothriospondylus magnus
    Owen, 1875[2]
  • Chondrosteosaurus magnus
    (Owen, 1875) Owen, 1876[3]

Ornithopsis (meaning "bird-likeness") is a genus of

sauropod dinosaur, from the Early Cretaceous of England. The type species, which is the only species seen as valid today, is O. hulkei, which is only known from fragmentary remains, and has been regarded by many authors as dubious.[5]

History of discovery

Vertebra BMNH R28632 in anterior view showing internal texture

British Museum of Natural History R2239, having been purchased from Mantell in 1838.[9]

BMNH R28632, a similar bone to BMNH R2239 was described in

John Whitaker Hulke, considering the taxon to be between pterosaurs and birds, and possibly allied with dinosaurs.[1] The genus name is derived from Greek ὄρνις, "bird" and ὄψις, "likeness".[4]

Owen revisisted the material in

Chondrosteosaurus gigas from the Wealden.[3]

Hulke described additional sauropod material from the Wealden in 1879, and reevaluated the designations used by Owen and Seeley. Hulke identified BMNH R28632 as the type of O. hulkei, rendering Bothriospondylus magnus and Chondrosteosaurus magnus as junior objective synonyms. As well, Hulke noted that the comment of Owen that the name Ornithopsis was misleading was false, as the vertebrae were lightly-constructed regardless of their relationships. Hulke also referred the genus Eucamerotus, named earlier by him in 1870, and the genus Chondrosteusaurus to Ornithopsis as junior synonyms, with other fossils found in the Wealden beds showing that they all shared the unique internal structure of Ornithopsis.[4] Though William Blows identified in 1995 that most of the Wealden sauropod material has been designated as dubious or intermediate, the type vertebra of Ornithopsis shows unique features in its lateral compression and a ventral ridge, and represents a diagnostic titanosauriform.[10][11]

Additional species

Hulke described pelvis material, BMNH R97, from the Wealden in 1882, found associated with a few vertebrae, as the new species Ornithopsis eucamerotus. He retained Eucamerotus and Chondrosteosaurus as synonyms of Ornithopsis, but suggested that O. hulkei should only contain the original vertebra BMNH R2239.[12][9] The designation by Hulke of BMNH R2239 as type conflicted with his earlier assertion that BMNH R28632 was the type, so Lydekker corrected this in 1888 by formally designated BMNH R28632 as the only type with the consultation of Seeley.[9]

Pelvis of Ornithopsis leedsii

Hulke described more material as Ornithopsis in 1887, for some vertebrae, ribs, a pelvis, and fragments collected in the Eyesbury Jurassic deposits of

Cetiosaurus oxoniensis.[13] The specimens named as Ornithopsis leedsii are stored as specimens BMNH R1985-1988, having been collected in May of 1892, and possibly being the first sauropod collected by Leeds and his brothers. Unlike the other specimens, O. leedsii came from the lower Callovian deposits of the Kellaways Formation below the Oxford Clay where most specimens were derived from.[14]

Hulke described a

Harry Govier Seeley, a proposal that was not endorsed at the time by Lydekker,[18] who also suggested that O. leedsii and O. humerocristatus were possibly distinct based on a difference in age, but that Chondrosteosaurus and Ornithopsis eucamerotus were synonyms of O. hulkei.[9] Ornithopsis leedsii was referred to as the species Pelorosaurus leedsi by Lydekker in 1895,[19] and as the taxon Cetiosaurus leedsi by Arthur Smith Woodward in the 1905,[20] which are incorrect spellings of the species name.[14]

Cetiosauriscus stewarti

Cetiosaurus leedsii (spelled as "leedsi") had additional remains referred to it by Woodward in 1905, including the anterior caudal vertebrae BMNH R1984, the distal caudals BMNH R1967, and the posterior skeleton BMNH R3078, which preserved most of the arm, leg, pelvis, and vertebrae behind the shoulders. They species was assigned to Cetiosaurus as the vertebrae were differently textured, so Woodward considered an assignment to Cetiosaurus more proper.

brevis.[22] Later in the same year, Huene revised his classification, naming the new genus Cetiosauriscus for O. leedsi as described by Woodward, and O. (?) greppini.[23]

Humerus of O. manseli

As the holotype material of Ornithopsis/Cetiosauriscus leedsii was not considered diagnostic, the more complete specimen BMNH R3078 was referred to the new taxon Cetiosauriscus stewarti, which was then designated as the type species of Cetiosauriscus as it contained the material Huene had originally named the new genus for.

eusauropod.[29] Ornithopsis greppini was given the new genus name Amanzia in a 2020 redescription of the original material.[27]

As Ischyrosaurus was used earlier by

Titanosauriformes, but lacked features to nail down its exact phylogenetic position.[34]

Description

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

Titanosauriformes.[11]

References

  1. ^ a b c d Seeley, H.G. (1870). "Ornithopsis, a gigantic animal of the Pterodacyle kind from the Wealden". Annals and Magazine of Natural History. 5 (4): 305–318.
  2. ^ a b Owen, R. (1875). "Monographs on the British Fossil Reptilia of the Mesozoic Formations. Part II. (Genera Bothriospondylus, Cetiosaurus, Omosaurus)". Monographs of the Palaeontographical Society: 15–93.
  3. ^ a b Owen, R. (1876). "Monograph on the Fossil Reptilia of the Wealden and Purbeck Formations. Supplement No. VII. Crocodilia (Poikilopleuron) and Dinosauria? (Chondrosteosaurus) [Wealden]". Monographs of the Palaeontographical Society: 1–7.
  4. ^
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  6. ^ Mantell, G.A. (1833). "Description of the Organic Remains of the Wealden, and particularly of those of the Strata of Tilgate Forest". The Geology of the South East of England. Cambridge University Press. pp. 232–288.
  7. ^ Mantell, G.A. (1833). "Observations on the Fossil Remains of the Hylaeosaurus, and other Saurian Reptiles, discovered in the Strata of Tilgate Forest, in Sussex". The Geology of the South East of England. Cambridge University Press. pp. 232–288.
  8. ^ Owen, R. (1854). "Monograph on the Fossil Reptilia of the Wealden Formations. Part II. Dinosauria". Monographs of the Palaeontographical Society: 1–54.
  9. ^ a b c d e Lydekker, R. (1888). Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. British Museum (Natural History). Department of Geology. pp. 1–309.
  10. ^ Blows, W.T. (1995). "The Early Cretaceous brachiosaurid dinosaurs Ornithopsis and Eucamerotus from the Isle of Wight, England". Palaeontology. 38 (1): 187–197.
  11. ^ a b Upchurch, P.; Mannion, P.D.; Barrett, P.M. (2011). "Sauropod dinosaurs". In Batten, D.J. (ed.). English Wealden Fossils. The Palaeontological Association. pp. 476–525.
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  20. ^ a b Woodward, A.S. (1905). "On parts of the skeleton of Cetiosaurus Leedsi, a sauropodous dinosaur from the Oxford Clay of Peterborough". Proceedings of the Zoological Society of London. 1 (January–April): 232–243.
  21. ^ Huene, F. (1921). "Ueber einen Sauropoden im obern Malm des Berner Jura". Eclogae Geologicae Helvetiae. 17: 80–94.
  22. ^ Huene, F. (1927). "Sichtung der Grundlagen der jetzigen Kenntnis der Sauropoden". Eclogae Geologicae Helvetiae. 20: 444–470.
  23. ^ von Huene, F. (1927). "Short review of the present knowledge of the Sauropoda" (PDF). Memoirs of the Queensland Museum. 8: 121–126.
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  26. ^ International Commission on Zoological Nomenclature (1995). "Opinion 1801. Cetiosauriscus Huene, 1927 (Reptilia, Sauropodomorpha): Cetiosauriscus stewarti Charig, 1980 designated as type species". The Bulletin of Zoological Nomenclature. 52: 113.
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  29. doi:10.1111/zoj.12029
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  30. ^ Martill, D.M.; Earland, S.; Naish, D. (2006). "Dinosaurs in marine strata: evidence from the British Jurassic, including a review of the allochthonous vertebrate assemblage from the marine Kimmeridge Clay Formation (Upper Jurassic) of Great Britain". ColectivoArqueológico-Paleontológico Salense. Actas de las III Jornadas sobre Dinosaurios y su Entorno. pp. 1–31.
  31. ^ von Huene, F. (1909). Skizze zu einer Systematik und Stammesgeschichte der Dinosaurier. Centralblatt für Mineralogie, Geologie und Paläontologie 1909:12-22. [German]
  32. ISBN 0-89464-985-X
  33. ^ Steel, R. (1970). Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Part 14. Gustav Fischer Verlag:Stuttgart p. 1-87.
  34. ^ Paul M. Barrett, Roger B.J. Benson and Paul Upchurch (2010). "Dinosaurs of Dorset: Part II, the sauropod dinosaurs (Saurischia, Sauropoda) with additional comments on the theropods". Proceedings of the Dorset Natural History and Archaeological Society 131: 113–126.

External links

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