Oplosaurus

Last updated

Oplosaurus
Temporal range: Early Cretaceous 130–125  Ma
O
S
D
C
P
T
J
K
Pg
N
Oplosaurus.png
Illustration of the holotype tooth in multiple views
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Macronaria
Genus: Oplosaurus
Gervais, 1852
Species:
O. armatus
Binomial name
Oplosaurus armatus
Gervais, 1852

Oplosaurus (meaning "armed or weapon lizard" or "armoured lizard"; see below for discussion) was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is known from a single tooth usually referred to the contemporaneous "wastebasket taxon" Pelorosaurus , although there is no solid evidence for this.

Contents

History and taxonomy

In 1852 geologist Thomas Wright reported the find of a large reptilian tooth from the Wealden Clay near Brixton Bay on Wight. Wright had presented the find to several experts, among them Richard Owen, David Forbes, George Robert Waterhouse and Samuel Pickworth Woodward but only Gideon Mantell came with a useful suggestion pointing to a similarity with the teeth of the dinosaur Hylaeosaurus . Not convinced by this, Wright concluded that the tooth, in view of its sharpness, belonged to a carnivorous reptile of unknown affinities. [1]

Wright had also asked the French paleontologist Paul Gervais for his opinion on the fossil. Gervais in 1852 based the type species Oplosaurus armatus on it. The generic name would normally read as "armoured lizard" from the Greek hoplon, "body armour". The usual story about the — given the fact that Oplosaurus is not known to be armoured — odd choice of name is that Gervais named this large, well-preserved tooth (holotype BMNH R964) under the mistaken belief that its owner was an armoured dinosaur like Hylaeosaurus following Mantell's suggestion. [2] However, recent research by Ben Creisler shows that Gervais compared it to Mosasaurus , not Hylaeosaurus, and that the name may have been intended as "armed lizard", with the teeth as the weapons of a carnivore, as hoplon can also mean "weapon" (although this would make the specific name redundant, as armatus too means "armed" in Latin). [3]

Richard Lydekker (1888) suggested that a maxilla with a tooth (BMNH R751), also from the Isle of Wight, was another exemplar of this animal, but this opinion has not been substantiated. [4] Lydekker also used the improved spelling "Hoplosaurus" but the original Oplosaurus has priority.

The tooth is large, 85 mm (3.35 in) tall in total, with a spatulate crown 52 mm (2.05 in) tall, comparable to Brachiosaurus ; it has a pointed tip, a slightly compressed form "cheek" to tongue, a slight convexity to the base of the tongue-facing side, and wear facets. [2] [3] It is vaguely like a Brachiosaurus tooth, which is why the genus has for a time been referred to the Brachiosauridae. [5] Earlier, Oplosaurus was typically referred to Pelorosaurus following an opinion of Friedrich von Huene in 1909, although Pelorosaurus is based on fragmentary remains that do not include teeth, making it impossible to prove the identity. (See Naish and Martill (2001) for a good review of Oplosaurus and Wealden sauropods in general; here is a more recent informal summation of the state of work.)

Given how poor the Pelorosaurus holotype material is, and that it doesn't include teeth, recent reviews have retained Oplosaurus as a potentially valid but poorly known genus. [6] Darren Naish, a British palaeontologist familiar with Wealden sauropods, has suggested informally that the genus may be a turiasaur but also co-authored an article concluding it was a member of the Camarasauridae. [7] In any case, it likely belongs to the more general Macronaria. [8] A 2022 review considered it to be a potential turiasaur, echoing Naish's suggestion. [9]

Paleobiology

As Naish and Martill point out, the tooth is comparable in size to that of Brachiosaurus , indicating that the owner was a large sauropod; [2] as a possible turiasaur, the size should not change drastically. It would have been a quadrupedal herbivore, possibly around 25 m (82 ft) long. [2]

Related Research Articles

<i>Hypsilophodon</i> Extinct genus of dinosaurs

Hypsilophodon is a neornithischian dinosaur genus from the Early Cretaceous period of England. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this into question.

<i>Hylaeosaurus</i> Ankylosaurian dinosaur genus from Early Cretaceous Period

Hylaeosaurus is a herbivorous ankylosaurian dinosaur that lived about 136 million years ago, in the late Valanginian stage of the early Cretaceous period of England. It was found in the Grinstead Clay Formation.

The Isle of Wight is one of the richest dinosaur localities in Europe, with over 20 species of dinosaur having been recognised from the early Cretaceous Period, some of which were first identified on the island, as well as the contemporary non-dinosaurian species of crocodile, turtle and pterosaur.

<i>Valdosaurus</i> Extinct genus of dinosaurs

Valdosaurus is a genus of bipedal herbivorous iguanodont ornithopod dinosaur found on the Isle of Wight and elsewhere in England, Spain and possibly also Romania. It lived during the Early Cretaceous.

<i>Pelorosaurus</i> Genus of dinosaur

Pelorosaurus 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. Thomas Holtz estimated its length at 24 meters.

<i>Neovenator</i> Extinct genus of dinosaurs

Neovenator is a genus of carcharodontosaurian theropod dinosaur. It is known from several skeletons found in the Early Cretaceous (Hauterivian-Barremian) Wessex Formation on the south coast of the Isle of Wight, southern England. It is one of the best known theropod dinosaurs from the Early Cretaceous of Europe.

<i>Aepisaurus</i> Extinct species of reptile

Aepisaurus was a genus of sauropod dinosaur from the Albian-age Lower Cretaceous Grès vert of Département du Vaucluse, France, around 100.5 million years ago. It is an obscure genus from an unknown family, represented by a single humerus, now partly lost. Despite its lack of popularity, or perhaps because of it, it has been misspelled several ways in the scientific literature, with multiple dates given to the year of description as well.

Calamospondylus is a genus of theropod dinosaur. It lived during the Early Cretaceous and its fossils were found on the Isle of Wight in southern England. The type species is C. oweni.

<i>Asiatosaurus</i> Extinct genus of dinosaurs

Asiatosaurus is an extinct genus of herbivorous sauropod dinosaur which lived during the Early Cretaceous in Mongolia and China. The type species is known only from teeth, making it difficult to rely on information until more specimens are found to expand our knowledge, and another species is known, also based on scant remains; both are now classified as nomina dubia.

<i>Calamosaurus</i> Extinct genus of dinosaurs

Calamosaurus was a genus of small theropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is based on two cervical vertebrae, collected by Reverend William Fox.

<i>Cardiodon</i> Extinct genus of dinosaurs

Cardiodon was a herbivorous genus of sauropod dinosaur, based on a tooth from the late Bathonian-age Middle Jurassic Forest Marble Formation of Wiltshire, England. Historically, it is very obscure and usually referred to Cetiosaurus, but recent analyses suggest that it is a distinct genus, and possibly related to Turiasaurus. Cardiodon was the first sauropod genus named.

<i>Valdoraptor</i> Extinct genus of dinosaurs

Valdoraptor is a genus of theropod dinosaur from the Early Cretaceous. Its fossils were found in England. It is known only from bones of the feet. The holotype, BMNH R2559, was found near Cuckfield in layers of the Tunbridge Wells Sand Formation dating from the late Valanginian. The specimen is damaged lacking parts of the upper and lower ends. It has a conserved length of 215 millimetres (8.5 in) and an estimated length of 240 millimetres (9.4 in). This genus is paleontologically significant for being the first ornithomimosaur specimen known from England and represents the earliest record of ornithomimosaurs.

<i>Regnosaurus</i> Extinct genus of dinosaurs

Regnosaurus is a genus of herbivorous stegosaurian dinosaur that lived during the Early Cretaceous Period in what is now England. It was one of the first stegosaurs discovered.

Eucamerotus was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation (Wealden) of the Isle of Wight, England.

<i>Ornithopsis</i> Extinct genus of dinosaurs

Ornithopsis 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.

<i>Iuticosaurus</i> Extinct genus of dinosaurs

Iuticosaurus is a genus of titanosaur sauropod dinosaur from the Early Cretaceous of the Isle of Wight. Two species have been named: I. valdensis and I. lydekkeri. I. valdensis was found in the Wessex Formation and I. lydekkeri in the younger Upper Greensand.

<i>Xenoposeidon</i> Extinct genus of dinosaurs

Xenoposeidon is a genus of rebbachisaurid sauropod dinosaur from the Early Cretaceous of England, living about 140 million years ago. It is known from a single partial vertebra with unusual features, unlike those of other sauropods. This bone was first discovered in the early 1890s but received little attention until it was found by University of Portsmouth student Mike Taylor, who formally described and named it in 2007 with Darren Naish.

<i>Hypselospinus</i> Extinct genus of dinosaurs

Hypselospinus is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon by Richard Lydekker in 1889, the specific name honouring William Henry Fitton.

<i>Haestasaurus</i> Extinct genus of dinosaurs

Haestasaurus is a genus of herbivorous sauropod dinosaur, belonging to the Macronaria, that during the Early Cretaceous lived in the area of present-day England. The only species is Haestasaurus becklesii.

References

  1. Wright, T. (1852). Contributions to the palaeontology of the Isle of Wight. Annals and Magazine of Natural History 2:87-93.
  2. 1 2 3 4 Naish, D., and Martill, D.M. (2001). Saurischian dinosaurs 1: Sauropods. In: Martill, D.M., and Naish, D. (eds.). Dinosaurs of the Isle of Wight. The Palaeontological Association:London 185-241. ISBN   0-901702-72-2
  3. 1 2 Gervais, P. (1852). Zoologie et paléontologie française (animaux vertébrés) (1st edition). A. Bertrand:Paris, 271 p. [French]
  4. Lydekker, R. (1888). "Note on a new Wealden Iguanodont and other Dinosaurs". Quarterly Journal of the Geological Society. 44 (1–4): 46–61. doi:10.1144/GSL.JGS.1888.044.01-04.08. S2CID   129803661.
  5. McIntosh, J.S. (1990). Sauropoda. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria. University of California Press:Berkeley 345-401. ISBN   0-520-06727-4
  6. Upchurch, P.M., Barrett, P.M., and Dodson, P. (2004). Sauropoda. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (2nd edition). University of California Press:Berkeley 259-322. ISBN   0-520-24209-2
  7. Sánchez-Hernández, B; Benton, M; Naish, D (2007). "Dinosaurs and other fossil vertebrates from the Late Jurassic and Early Cretaceous of the Galve area, NE Spain" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology. 249 (1–2): 180–215. doi:10.1016/j.palaeo.2007.01.009.
  8. Naish, D.; Martill, D. M. (2007). "Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia". Journal of the Geological Society. 164 (3): 493–510. doi:10.1144/0016-76492006-032. S2CID   19004679.
  9. Poropat, S.F.; Frauenfelder, T.G.; Mannion, P.D.; Rigby, S.L.; Pentland, A.H.; Sloan, T.; Elliott, D.A. (2022). "Sauropod dinosaur teeth from the lower Upper Cretaceous Winton Formation of Queensland, Australia and the global record of early titanosauriforms". Royal Society Open Science. 9 (7): 220381. doi:10.1098/rsos.220381. PMC   9277269 . PMID   35845848.