Macrurosaurus

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Macrurosaurus
Temporal range: late Albian, 105–100  Ma
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Macrurosaurus semnus.jpg
Vertebra of M. semnus
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Macronaria
Clade: Titanosauriformes
Genus: Macrurosaurus
Seeley, 1869
Type species
Macrurosaurus semnus
Seeley, 1869
Other species
Synonyms

Macrurosaurus (meaning "large-tailed lizard") is the name given to a genus of dinosaur from the Early Cretaceous. It was a titanosauriform which lived in what is now England. The type species, M. semnus, was named in 1876. [1] A second species, M. platypus, may also exist. [2] [3]

Contents

History

The genus Macrurosaurus was named by Harry Govier Seeley in 1869 in his index of fossils from the Cambridge Greensand. [4] In 1876 Seeley more thoroughly described the type species, Macrurosaurus semnus, making the name valid. [1] The generic name is derived from Greek makros, "large", and oura, "tail". The specific name is derived from Greek semnos, "stately" or "impressive". A second species, M. platypus, from the Chalk Group of England, may also exist. [2] Seeley in 1869 named it as a species of the ankylosaurid Acanthopholis but Friedrich von Huene named it as a second species of Macrurosaurus in 1956. [3] It is known from the specimen CAMSM B55454-55461. [5] In 1999 Xabier Pereda-Superbiola and Paul M. Barrett reviewed all Acanthopholis material. They concluded that all species were nomina dubia whose syntype specimens were composites of non-diagnostic ankylosaur and ornithopod remains. For example, the metatarsals included in the syntype series of Acanthopholis platypus are from a sauropod, but the remaining syntypes are not. [6]

Metatarsals of M. platypus Macrurosaurus platypus metatarsals.jpg
Metatarsals of M. platypus

The holotype of Macrurosaurus, SM B55630, consists of two series of caudal vertebrae found around 1864 near Cambridge, England in the Cambridge Greensand, strata themselves deposited during the Cenomanian but containing reworked fossil material dating perhaps from around the late Albian. [7] The first was acquired by the Woodwardian Museum from William Farren who had it dug up at Coldhams Common near Barnwell. This series is made up of 25 proximal vertebrae. The second was found by Reverend W. Stokes-Shaw at a slightly more western location near Barton. It contained fifteen smaller distal vertebrae, from the tail end. Seeley, acting on the presumption that both finds belonged to the same species if not individual, combined the two series into one tail of about 4.5 metres length.

Other fragmentary fossils from England ( Acanthopholis platypus), [2] France and Argentina have later been referred to Macrurosaurus [8] but the identity is today doubted. [2]

A 2022 review considered Macrurosaurus to be an indeterminate macronarian, while "Acanthopholis" platypus was treated as indeterminate within Eusauropoda or Neosauropoda. [9]

Description

Macrurosaurus was by Seeley himself estimated to be about ten metres long. Often a length of around twelve metres (40 ft) is indicated in the popular literature. The vertebrae in front are procoelous, meaning that the vertebral centra are hollow at the front end and convex at the back. Those behind are amphicoelous: hollow at both ends. Seeley assumed that the full count of tail vertebrae would have been about fifty.

Classification

Macrurosaurus was by Seeley assigned to the Dinosauria. Richard Lydekker in 1888 understood it belonged to the Sauropoda. [10] In 1929 Friedrich von Huene referred it to the Titanosauridae. [11] In recent years however, it has been commonly concluded that the species cannot be further determined than a more general Titanosauriformes. Also it is today often seen as a nomen dubium .

Related Research Articles

Gigantosaurus is a dubious genus of sauropod dinosaur 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, the distal end of a tibia, a cast of the right radius, a cast of phalanx and an osteoderm. 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.

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

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<span class="mw-page-title-main">Harry Seeley</span> 19th century British paleontologist

Harry Govier Seeley was a British paleontologist.

<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>Cryptosaurus</i> Extinct genus of dinosaurs

Cryptosaurus is a dubious genus of dinosaur known from a partial femur from the Late Jurassic of England. The sole species is Cryptosaurus eumerus.

<i>Acanthopholis</i> Genus of reptiles (fossil)

Acanthopholis is a genus of ankylosaurian dinosaur in the family Nodosauridae that lived during the Late Cretaceous Period of England. A single species, A. horrida, exists.

<i>Cetiosauriscus</i> Genus of reptiles (fossil)

Cetiosauriscus is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian in what is now England. A herbivore, Cetiosauriscus had — by 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 in weight.

<i>Janenschia</i> Extinct genus of dinosaurs from late Jurassic in Lindi Region, Tanzania

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

Anoplosaurus is an extinct genus of herbivorous nodosaurid dinosaur, from the late Albian-age Lower Cretaceous Cambridge Greensand of Cambridgeshire, England. It has in the past been classified with either the armored dinosaurs or the ornithopods, but current thought has been in agreement with the "armored dinosaur" interpretation, placing it in the Ankylosauria.

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

Bothriospondylus is a dubious genus of neosauropod sauropod dinosaur. It lived during the Late Jurassic.

<i>Syngonosaurus</i> Extinct genus of ornithopod dinosaur

Syngonosaurus is an extinct genus of ornithopod dinosaur from the Early Cretaceous. It was an iguanodontian discovered in England and was first described in 1879. The type species, S. macrocercus, was described by British paleontologist Harry Seeley in 1879 and it was later synonymised with Acanthopholis, but the genus was reinstated in a 2020 study, when Syngonosaurus and Eucercosaurus were reinterpreted as basal iguanodontians.

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

"Ischyrosaurus" was a genus of sauropod dinosaur from the Kimmeridgian-age Upper Jurassic Kimmeridge Clay of Dorset, England.

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

Ornithopsis was a medium-sized Early Cretaceous sauropod dinosaur, from England. The type species, which is the only species seen as valid today, is O. hulkei.

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

Thecospondylus is a dubious genus of dinosaur from the Early Cretaceous of England. Scientists are unsure as to whether Thecospondylus was a saurischian or an ornithischian.

<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>Ornithostoma</i> Genus of azhdarchoid pterosaur from the Early Cretaceous

Ornithostoma is a genus of pterodactyloid pterosaur that lived during the Early Cretaceous period of Europe, around 110 million years ago. Ornithostoma was once thought to have been a senior synonym of the pteranodontid Pteranodon due to its toothless anatomy and prior naming.

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

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 and was noted as being similar to that of Gigantosaurus. 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. Thomas Holtz estimated its length at 25 meters (82 ft).

<i>Camposipterus</i> Genus of ornithocheiran pterosaur from the Early Cretaceous

Camposipterus is a genus of pterodactyloid pterosaur from the Early Cretaceous of England. Fossil remains of Camposipterus dated back to the Early Cretaceous, about 112 million years ago.

<i>Ikrandraco</i> Genus of lonchodraconid pterosaur from the Early Cretaceous

Ikrandraco is a genus of lonchodraconid pterodactyloid pterosaur known from Lower Cretaceous rocks in northeastern China and the Cambridge Greensand of the UK. It is notable for its unusual skull, which features a crest on the lower jaw.

<i>Aerodraco</i> Genus of anhanguerid pterosaur from the Cretaceous period

Aerodraco is a genus of anhanguerid pterosaur from the Albian–Cenomanian-age Cambridge Greensand of England. It contains only one species, Aerodraco sedgwickii. It was originally assigned to the genus Pterodactylus.

References

  1. 1 2 H.G. Seeley, 1876, "On Macrurosaurus semnus (Seeley), a long tailed animal with procoelous vertebrae from the Cambridge Upper Greensand, preserved in the Woodwardian Museum of the University of Cambridge", Quarterly Journal of the Geological Society of London32: 440-444 doi : 10.1144/GSL.JGS.1876.032.01-04.50
  2. 1 2 3 4 Seeley, H.G. (1879). "On the Dinosauria of the Cambridge Greensand". Quarterly Journal of the Geological Society. 35 (1–4): 591–636. doi:10.1144/GSL.JGS.1879.035.01-04.42. ISSN   0370-291X. S2CID   129277596.
  3. 1 2 von Huene, F. (1956) "Palaeontologie und Phylogenie der niederen Tetrapoden"
  4. Seeley, Harry Govier (1869). "Index to the fossil remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata, arranged in the Woodwardian Museum of the University of Cambridge". Annals and Magazine of Natural History. 5 (27): 1–143. doi:10.1080/00222937008696143. ISSN   0374-5481.
  5. Seeley, H.G. (1871). "XXXVII.— On Acanthopholis platypus (Seeley), a Pachypod from the Cambridge Upper Greensand". Annals and Magazine of Natural History. 8 (47): 305–318. doi:10.1080/00222937108696494. ISSN   0374-5481.
  6. Superbiola, X.P.; Barrett, P.M. (1999). "A systematic review of ankylosaurian dinosaur remains from the Albian-Cenomanian of England". Special Papers in Palaeontology. 60: 177–208.
  7. Unwin, D.M. (2003). "On the phylogeny and evolutionary history of pterosaurs". In Buffetaut, Eric; Mazin Jean-Michel (eds.). Evolution and Palaeobiology of Pterosaurs. Geological Society Special Publication 217. London: Geological Society. pp. 139–190. ISBN   1-86239-143-2.
  8. F. v. Huene. 1927. Contribución a la paleogeografía de Sud América [Contribution to the paleogeography of South America]. Boletín de la Academia Nacional de Ciencias de la República Argentina 30:231-294
  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.
  10. R. Lydekker. 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), London 1-309
  11. F. v. Huene, 1929, "Los sauriquios y ornitisquios del Cretáceo argentino", Anales del Museo de La Plata, serie 2 3: 1-196