Acanthopholis

Acanthopholis (/ˌækənˈθɒfoʊlɪs/; meaning "spiny scales") is a genus of ankylosaurian dinosaur in the family Nodosauridae that lived during the Early Cretaceous Period of England.

Acanthopholis
Temporal range: Early Cretaceous
Acanthopholis suposed
Artist's rendering of Acanthopholis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Family: Nodosauridae
Subfamily: Acanthopholinae
Nopcsa, 1923
Genus: Acanthopholis
Huxley, 1867
Species
  • A. horrida Huxley, 1867 (type)
Synonyms
  • Syngonosaurus macrocercus Seeley, 1869

History

Acanthopholis copia
Hypothetical restoration

Around 1865 commercial fossil collector John Griffiths found some dinosaurian remains, including osteoderms, at the shoreline near Folkestone in Kent, which he sold to the metallurgist Dr. John Percy. Percy brought them to the attention of Thomas Henry Huxley, who paid Griffiths to dig up all fossils he could find at the site. Despite being hampered by the fact that it was located between the tidemarks, he managed to uncover several additional bones and parts of the body armour.

In 1867 Huxley named the genus and species Acanthopholis horridus.[1] The dinosaur's generic name refers to its armour, being derived from Greek άκανθα akantha meaning 'spine' or 'thorn' and φόλις pholis meaning 'scale'. The specific name horridus means 'frightening' or 'rough' in Latin. Arthur Smith Woodward emended the species name to Acanthopholis horrida in 1890 because pholis is feminine.[2]

The type specimens, cotypes GSM 109045-GSM 109058, were found in the Chalk Group,[3] a formation itself dating to the Albian to Cenomanian stages around 100 million years ago.. The specimens consist of three teeth, a basicranium, a dorsal vertebra, spikes and scutes.

Syngonosaurus
Vertebra of Syngonosaurus

In 1869 Harry Govier Seeley named several new species of the genus based on remains from the Cambridge Greensand: Acanthopholis macrocercus, based on specimens CAMSM B55570-55609; Acanthopholis platypus (CAMSM B55454-55461);[4] and Acanthopholis stereocercus (CAMSM B55558 55569).[5] Later, Seeley split the material of Acanthopholis stereocercus and based a new species of Anoplosaurus on part of it: Anoplosaurus major. He also described a new species, Acanthopholis eucercus, on the basis of six caudal vertebrae (CAMSM 55552-55557).[6] In 1902 however Franz Nopcsa changed it into another species of Acanthopholis: Acanthopholis major. Nopcsa at the same time renamed Anoplosaurus curtonotus into Acanthopholis curtonotus. In 1879 Seeley named the genus Syngonosaurus based on part of the type material of A. macrocercus. In 1956 Friedrich von Huene renamed A. platypus into Macrurosaurus platypus.

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. They also found two previously unpublished names which Seeley had used to label museum specimens: "Acanthopholis hughesii" indicated SMC B55463-55490 and "Acanthopholis keepingi" SMC B55491-55526. Both names were not proposed by them as new species and are nomina nuda.[7]

Acanthopholis's armour consisted of oval keeled plates set almost horizontally into the skin, with long spikes protruding from the neck and shoulder area, along the spine. Acanthopholis was quadrupedal and herbivorous. Its size has been estimated to be in the range of 3 to 5.5 meters (10 to 18 ft) long and approximately 380 kilograms (840 lb) in weight.

Acanthopholis was originally assigned to the Scelidosauridae by Huxley. In 1902 Nopcsa created a separate family Acanthopholididae. Later, he named Acanthopholinae as a subfamily. In 1928, he corrected Acanthopholididae to Acanthopholidae. Today Acanthopholis is considered a member of the Nodosauridae within the Ankylosauria.

See also

Notes

  1. ^ Huxley, T.H., 1867, "On Acanthopholis horridus, a new reptile from the Chalk-Marl", Geological Magazine, 4: 65-67
  2. ^ A.S. Woodward and C.D. Sherborn, 1890, A Catalogue of British Fossil Vertebrates Dulao & Company, London pp. 396
  3. ^ Etheridge, R., 1867, "On the stratigraphical position of Acanthopholis horridus, a new reptile from the Chalk Marl", Geological Magazine, 4: 67-69
  4. ^ Seeley, H.G., 1871, "On Acanthopholis platypus (Seeley), a pachypod from the Cambridge Upper Greensand", Annals and Magazine of Natural History, 8: 305-318
  5. ^ Seeley, H.G., 1869, Index to the Fossil Remains of Aves, Ornithosauria, and Reptilia from the Secondary Strata arranged in the Woodwardian Museum of the University of Cambridge. Deighton, Bell and Co., Cambridge, 143 pp
  6. ^ Seeley, H.G., 1879, "On the Dinosauria of the Cambridge Greensand", Quarterly Journal of the Geological Society 35: 591-636
  7. ^ Pereda-Suberbiola, X. & Barrett, P.M., 1999, "A systematic review of ankylosaurian dinosaur remains from the Albian-Cenomanian of England", Special Papers in Palaeontology, 60: 177-208

References

  • Carpenter, Kenneth (2001). "Phylogenetic Analysis of Ankylosauria". In Carpenter, Kenneth (ed.). The Armored Dinosaurs. Indiana University Press. pp. 455–480. ISBN 0-253-33964-2.

External links

A. horridus

A. horridus may refer to:

Abdopus horridus, an octopus species in the genus Abdopus

Acanthopholis horridus, an ankylosaurid dinosaur species that lived during the Early Cretaceous Period around 100 million years ago

Acanthosicyos horridus, an unusual melon species found only in Namibia

Argosarchus horridus, the New Zealand giant stick insect, a stick insect species endemic to New Zealand

Albian

The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian.

Ankylosaurinae

Ankylosaurinae is a subfamily of ankylosaurid dinosaurs, existing from the Early Cretaceous about 105 million years ago until the end of the Late Cretaceous, about 66 mya. Many genera are included in the clade, such as Ankylosaurus, Pinacosaurus, Euoplocephalus, and Saichania.

Anoplosaurus

Anoplosaurus (meaning "unarmored or unarmed lizard") 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.

Bienosaurus

Bienosaurus (meaning "Bien's lizard") is a genus of thyreophoran dinosaur from the Lower Jurassic (probably Sinemurian) Lower Lufeng Formation in Yunnan Province in China.

Cambridge Greensand

The Cambridge Greensand is a geological formation in England whose strata date back to the Cenomanian stage of the Late Cretaceous. It forms the transitional bed between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the lowest member bed of the West Melbury Marly Chalk Formation. The lithology is made out of glauconitic marl, with a concentration of phosphatic nodules and bones at the base. Dinosaur remains are among the fossils that have been recovered from the formation.

Cenomanian

The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name.

As a unit of geologic time measure, the Cenomanian age spans the time between 100.5 ± 0.9 Ma and 93.9 ± 0.8 Ma (million years ago). In the geologic timescale it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts approximately at 95 M.a.

The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States.

At the end of the Cenomanian an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli Event", that is associated with a minor extinction event for marine species.

Craterosaurus

Craterosaurus (meaning krater reptile or bowl reptile) was a genus of stegosaurid dinosaur. It lived during the Early Cretaceous (Valanginian to Barremian stages) around 145-136 million years ago. Its fossils were found in the Woburn Sands Formation of England. Craterosaurus may actually be a junior synonym of Regnosaurus, but only one fossil, a partial vertebra, was recovered.

The type (and only known) species is Craterosaurus pottonensis, described in 1874 by Harry Seeley. The specific name refers to the Potton bonebed. Seeley mistook the fossil, holotype SMC B.28814, for the base of a cranium. Franz Nopcsa in 1912 correctly identified it as the front part of a neural arch. Craterosaurus was placed in Stegosauria by Galton, although subsequent authors did not recognize Craterosaurus as a distinct, valid taxon.

Dongyangopelta

Dongyangopelta is an extinct genus of nodosaurid ankylosaurian dinosaur known from the "middle" Cretaceous Chaochuan Formation (Albian or Cenomanian stage) of Dongyang, Zhejiang Province, China. Dongyangopelta was first named by Rongjun Chen, Wenjie Zheng, Yoichi Azuma, Masateru Shibata, Tianliang Lou, Qiang Jin and Xingsheng Jin in 2013 and the type species is Dongyangopelta yangyanensis. It differs from Zhejiangosaurus, the second nodosaurid from southeast China, in the characters of presacral rod, ilium, and femur. Donyangopelta is distinguishable from Zhejiangosaurus only on the basis of the morphology of its pelvic shield.

Hemidactylus acanthopholis

Hemidactylus acanthopholis is a species of house geckos from the Tirunelveli in southern Tamil Nadu. Bearing a superficial resemblance to Hemidactylus maculatus, the species is usually found on large rocks or boulders. Growing 20–23 cm (7.9–9.1 in) in length, the species is an overall brown color, but has dark stripes on its back. It takes its name from the warty protuberances running along its dorsal surface.

Invictarx

Invictarx is a genus of herbivorous nodosaurid dinosaur from New Mexico dating from the early Campanian epoch of the Late Cretaceous.

Macrurosaurus

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 Europe.

The genus Macrurosaurus was named by Harry Govier Seeley in 1869 but not yet described so that it remained a nomen nudum. In 1876 Seeley described the type species, Macrurosaurus semnus, making the name valid. No other species are known. The generic name is derived from Greek makros, "large", and oura, "tail". The specific name is derived from Greek semnos, "stately" or "impressive".

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 Aptian but containing reworked fossil material dating perhaps from around 130 million years ago, the Barremian. 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), France and Argentina have later been referred to Macrurosaurus but the identity is today doubted.

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.

Macrurosaurus was by Seeley assigned to the Dinosauria. Richard Lydekker in 1888 understood it belonged to the Sauropoda. In 1929 Friedrich von Huene referred it to the Titanosauridae. 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.

Mongolostegus

Mongolostegus is a genus of stegosaur from the Early Cretaceous (Aptian-Albian) of Mongolia. The type and only species is M. exspectabilis, known from a single specimen previously under the nomen nudum Wuerhosaurus mongoliensis.

Nodosauridae

Nodosauridae is a family of ankylosaurian dinosaurs, from the Late Jurassic to the Late Cretaceous period of what are now North America, Europe, Asia, Africa, and Antarctica.

Nodosaurus

Nodosaurus (meaning "knobbed lizard") is a genus of herbivorous ankylosaurian dinosaur from the Late Cretaceous, the fossils of which are found in North America.

Struthiosaurinae

Struthiosaurinae is a subfamily of ankylosaurian dinosaurs from the Cretaceous of Europe. It is defined as "the most inclusive clade containing Europelta but not Cedarpelta, Peloroplites, Sauropelta or Edmontonia" while being reinstated for a newly recognized clade of basal nodosaurids. Struthiosaurinae appeared at about exactly the same time as the North American subfamily Nodosaurinae. Struthiosaurines range all across the Cretaceous, the oldest genus being Europelta at an age of 112 Ma and the youngest being Struthiosaurus at about 85–66 Ma.

It was originally mentioned by Franz Nopcsa in 1923 as a subfamily of Acanthopholidae, along with the previously defined Acanthopholinae. The family has gone through many taxonomic revisions since it was defined by Nopcsa in 1902. It is now recognized as a junior synonym of the family Nodosauridae. The subfamily now includes the genera Anoplosaurus, Europelta, Hungarosaurus, and Struthiosaurus, designated as the type genus. Because of the instability of Acanthopholis, the generic namesake of Acanthopholinae, and its current identification as a nomen dubium, Struthiosaurinae, the next named group, was decidedly used over the older one.

A review of ankylosaur osteoderms was published in 2000, and reviewed the armour of Struthiosaurinae. The group was represented by the single genus Struthiosaurus, known from head, cervical, dorsal, sacral, and caudal scutes. Only a few head osteoderms were identified, so it is unknown how much of the skull was armoured. Many cervical and dorsal scutes have been preserved alongside species of Struthiosaurus. They include cervical bands, which are groups of osteoderms fused together and attached to the vertebrae, and large spines found on the shoulders of nodosaurids like Sauropelta and Edmontonia, although it is not known if the spines were fused like the later of separate like the former. It is quite possible that small ovoid scutes found on Struthiosaurus could have formed a pelvic shield like polacanthids. The caudal scutes of struthiosaurines are small and rough. Even though osteoderms are well-known, it is not certain where they were positioned on the body.

Tatisaurus

Tatisaurus is a genus of ornithischian dinosaur from the Early Jurassic from the Lower Lufeng Formation in Yunnan Province in China. Little is known as the remains are fragmentary.

Tianzhenosaurus

Tianzhenosaurus (Tianzhen + Greek sauros="lizard") is a genus of ankylosaurid dinosaurs discovered in Tianzhen County, at Kangdailiang near Zhaojiagou Village, in Shanxi Province, China, in the Late Cretaceous Huiquanpu Formation. Thus far, a virtually complete skull and postcranial skeleton have been assigned to the genus, which is monotypic (T. youngi Pang & Cheng, 1998).

This was a medium-sized ankylosaurian, the skull measuring 28 cm (11 in) in length, with a total body length around 4 m (13 ft).

Vickaryous et al. (2004) placed Tianzhenosaurus within the Ankylosauridae, nested as the sister group to Pinacosaurus. Some authors have suggested that Tianzhenosaurus is actually a junior synonym of Saichania chulsanensis.

Tsagantegia

Tsagantegia (; meaning "of Tsagan-Teg"; Tumanova, 1993) is a genus of medium-sized ankylosaurid dinosaur from the Late Cretaceous of Mongolia, during the Cenomanian stage.

The holotype specimen (GI SPS N 700/17), a complete skull, was recovered from the Bayan Shireh Formation (Cenomanian-Santonian), at the Tsagan-Teg ("White Mountain") locality, Dzun-Bayan, in the southeastern Gobi Desert, Mongolia. The genus is monotypic, including only the type species, T. longicranialis.

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