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''Altispinax'' (; "with high spines") is a
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of large predatory
theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
from the
Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145& ...
period (
Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretace ...
, 140 to 133 million years ago) of what is now the
Wadhurst Clay Formation The Wadhurst Clay Formation is a geological unit which forms part of the Wealden Group and the middle part of the now unofficial Hastings Beds. These geological units make up the core of the geology of the High Weald in the English counties of West ...
of
East Sussex East Sussex is a ceremonial and non-metropolitan county in South East England on the English Channel coast. It is bordered by Kent to the north and east, West Sussex to the west, and Surrey to the north-west. The largest settlement in East ...
,
England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...
.


History

Probably during the early 1850s,
fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
collector Samuel Husbands Beckles discovered some nodules with dinosaur bones in a quarry near
Battle, East Sussex Battle is a small town and civil parish in the local government district of Rother in East Sussex, England. It lies south-east of London, east of Brighton and east of Lewes. Hastings is to the south-east and Bexhill-on-Sea to the south. ...
. These he sent to palaeontologist
Richard Owen Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomist and paleontologist. Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Ow ...
, who reported them in 1856.Owen, R., 1856, ''Monograph on the fossil Reptilia of the Wealden Formation. Part IV''. Palaeontographical Society Monographs 10, 26 pp Owen had a
lithograph Lithography () is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by the German a ...
made by Joseph Dinkel of the main specimen, a series of three back
vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...
e with very tall spines, whose image was also shown in an 1884 edition of an 1855 volume of his standard work on British fossil reptiles, leading to the misunderstanding the fossils had been recovered close to 1884. Owen, who referred the specimens to ''
Megalosaurus bucklandii ''Megalosaurus'' (meaning "great lizard", from Greek , ', meaning 'big', 'tall' or 'great' and , ', meaning 'lizard') is an extinct genus of large carnivorous theropod dinosaurs of the Middle Jurassic period (Bathonian stage, 166 million years a ...
'', thought the vertebrae were part of the shoulder region and it has been assumed that he must have already known of the find in 1853 as he directed Benjamin Waterhouse Hawkins to put a hump on the back of his life-sized ''Megalosaurus'' sculpture in
Crystal Palace Crystal Palace may refer to: Places Canada * Crystal Palace Complex (Dieppe), a former amusement park now a shopping complex in Dieppe, New Brunswick * Crystal Palace Barracks, London, Ontario * Crystal Palace (Montreal), an exhibition building ...
Park, which again inspired other restorations from the 19th century.Naish, D. 2010. "Pneumaticity, the early years: Wealden Supergroup dinosaurs and the hypothesis of saurischian pneumaticity". In: Moody, R. T. J., Buffetaut, E., Naish, D. & Martill, D. M. (eds) ''Dinosaurs and Other Extinct Saurians: A Historical Perspective''. Geological Society, London, Special Publications 343, pp. 229-236 The fossil, now catalogued as NHMUK R1828, was probably found in a layer of the Hastings Bed Group dating from the late
Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretace ...
age. It consists of a series of three posterior dorsal vertebrae. Owen also reported the presence in the nodules of two right ribs and two additional series of two dorsal vertebral centra each. Olshevsky thought the holotype represented the eighth, ninth, and tenth dorsal vertebrae; later researchers, however, have assumed them to be the tenth, eleventh and twelfth. In 1888,
Richard Lydekker Richard Lydekker (; 25 July 1849 – 16 April 1915) was an English naturalist, geologist and writer of numerous books on natural history. Biography Richard Lydekker was born at Tavistock Square in London. His father was Gerard Wolfe Lydekker ...
compared these vertebrae with material referred to ''
Megalosaurus dunkeri ''"Megalosaurus" dunkeri'' is a dubious species of theropod dinosaur, known only from a single tooth. History ''"M." dunkeri'' was originally named and described by Wilhelm Dames on 16 December 1884 during a lecture.Dames, W.B. (1885). "Vorleg ...
'', a Cretaceous species represented by a single tooth found in Germany. In 1923
Friedrich von Huene Friedrich von Huene, born Friedrich Richard von Hoinigen, (March 22, 1875 – April 4, 1969) was a German paleontologist who renamed more dinosaurs in the early 20th century than anyone else in Europe. He also made key contributions about v ...
created a separate genus for ''Megalosaurus dunkeri''. He used the three vertebrae as the basis for this genus, noting that they were different from ''Megalosaurus'', and created the name ''Altispinax'' (meaning "with high spines") based on their appearance. Many later researchers concluded that ''Megalosaurus dunkeri'' had therefore received a new genus name as ''Altispinax dunkeri'', a combination actually used for the first time in 1939 by
Oskar Kuhn Oskar Kuhn (7 March 1908, Munich – 1990) was a German palaeontologist. Life and career Kuhn was educated in Dinkelsbühl and Bamberg and then studied natural science, specialising in geology and paleontology, at the University of Munich, f ...
. Later researchers considered ''Altispinax'' a ''
nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...
'' because the single tooth was undiagnostic. No relationship could be proven between the tooth and the vertebrae. The vertebrae were therefore given a new name in 1988 by
Gregory Paul Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dino ...
. Paul considered them to represent a possible new species of ''
Acrocanthosaurus ''Acrocanthosaurus'' ( ; ) is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, ' ...
'', which he named ''Acrocanthosaurus? altispinax''. The specific name was deliberately made identical to the old generic name, to emphasize that both referred to the vertebrae.Paul, G.S., 1988, ''Predatory Dinosaurs of the World''. Simon & Schuster, New York 464 pp As indicated by the question mark, Paul himself was uncertain about this assignment. For this reason, in 1991 a new genus, ''Becklespinax'', was named for the vertebrae by George Olshevsky, in honour of the original discoverer, Beckles. The new combination name of the
type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
''Acrocanthosaurus? altispinax'' thus became ''Becklespinax altispinax''.Olshevsky, G., 1991, ''A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2'', 196 pp The species names ''Altispinax altispinax'' and ''Altispinax lydekkerhueneorum'' are its
junior objective synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...
s. In 2016, a re-examination of this convoluted history of classification was published by Michael Maisch. Maisch concluded that von Huene, when he named ''Altispinax dunkeri'', deliberately based the species on the vertebrae and not on the ''Megalosaurus dunkeri'' tooth. Because both species were based on different type specimens, later researchers were wrong to consider them the same species. Rather, according to Maisch's interpretation of the rules of the
ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...
, ''Altispinax dunkeri'' (based on the tall-spined vertebrae) and ''Megalosaurus dunkeri'' (based on the tooth from Germany) are two distinct species that happen to share the same species name. Because the later names created by Paul and Olshevsky were based on the same vertebrae used by von Huene to name ''Altispinax dunkeri'', all of those later names must be considered junior objective synonyms (different names for exactly the same fossil), and ''Altispinax dunkeri'', having been named first, has priority as the correct name for this species.Maisch, M.W. (2016). The nomenclatural status of the carnivorous dinosaur genus ''Altispinax'' v. Huene, 1923 (Saurischia, Theropoda) from the Lower Cretaceous of England. ''Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen'', 280(2): 215-219.


Other species

Four other species would be named within the genus ''Altispinax''. In 1923 von Huene renamed ''Megalosaurus oweni'' Lydekker 1889, based on the
metatarsus The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the med ...
BMNH R2559, into ''Altispinax oweni''.Huene, F. von (1923). "Carnivorous Saurischia in Europe since the Triassic". ''Bulletin of the Geological Society of America'', 34: 449-458. In 1991 Olshevsky created a separate genus ''
Valdoraptor ''Valdoraptor'' (meaning "Wealden plunderer") 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 (incorrectly given by Owen as BMNH ...
'' for this species. In 1932 von Huene renamed ''Megalosaurus parkeri'' Huene 1923 into ''Altispinax parkeri''. This species in 1964 was given the separate generic name ''
Metriacanthosaurus ''Metriacanthosaurus'' (meaning "moderately-spined lizard") is a genus of metriacanthosaurid dinosaur from the upper Oxford Clay of England, dating to the Late Jurassic period, about 160 million years ago (lower Oxfordian). History of discove ...
''.


Description

Paul in 1988 tentatively estimated that ''Altispinax'' weighed 1 tonne (1.1 short tons) and was shorter than the type specimen of ''Acrocanthosaurus atokensis'' which measures about 8 meters (26 ft) long. The three ''A. dunkeri'' back vertebrae from Sussex have about thirty-five centimetres high
neural spine The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...
s or ''processus spinosi'', about as relatively tall as those of ''
Ichthyovenator ''Ichthyovenator'' is a genus of spinosaurid dinosaur that lived in what is now Laos, sometime between 125 and 113 million years ago, during the Aptian stage of the Early Cretaceous period. It is known from fossils collected from the Grè ...
''. These show irregular rugosities on the upper third part. According to
Ralph Molnar Ralph E. Molnar is a paleontologist who had been Curator of Mammals at the Queensland Museum and more recently associated with the Museum of Northern Arizona. He is also a research associate at the Texas natural Science Centre. He co-authored descr ...
the two spines closest to the skull are ankylosed or fused. The single closest spine is only about two-thirds the height of the others and looks as it has broken off, while the spine behind partly overgrows the gap. This Molnar explained as a result of injury to a back frill, the wound later closing from behind.Molnar, R. E., 2001, Theropod paleopathology: a literature survey: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 337-363. In 2003,
Darren Naish Darren William Naish is a British vertebrate palaeontologist, author and science communicator. As a researcher, he is best known for his work describing and reevaluating dinosaurs and other Mesozoic reptiles, including ''Eotyrannus'', ''Xenopos ...
gave a different interpretation, suggesting the gap was natural. He denied that the front two vertebrae were ankylosed but observed that the spines of eleventh and twelfth vertebrae were joined at the top. The spines are also transversely expanded above, with a width of about fifty-five millimetres. Naish also pointed out that Owen had noted the large depressions on the
neural arch The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...
sides and had explained them as a result of pneumatisation, the first time this phenomenon would explicitly have been observed with a dinosaur.Naish, D., 2003, "A definitive allosauroid (Dinosauria; Theropoda) from the Lower Cretaceous of East Sussex", ''Proceedings of the Geologists’ Association'' 114: 319-326 In 2006 however, it was reported that in 1837
Christian Erich Hermann von Meyer Christian Erich Hermann von Meyer (3 September 1801 – 2 April 1869), known as Hermann von Meyer, was a German palaeontologist. He was awarded the 1858 Wollaston medal by the Geological Society of London. Life He was born at Frankfurt am Ma ...
already had commented on this phenomenon with the
Saurischia Saurischia ( , meaning "reptile-hipped" from the Greek ' () meaning 'lizard' and ' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithis ...
in general. The discovery of a back crest incorporating only two high vertebrae in ''
Concavenator ''Concavenator'' is an extinct genus of theropod dinosaur that lived approximately 130 million years ago during the early Cretaceous period (Barremian age). The type species is ''C. corcovatus''; ''Concavenator corcovatus'' means " Cuenca hunter ...
'', in 2010 provided corroboration that the short anterior ''Altispinax'' spine may be complete. Olshevsky originally assigned ''Altispinax'' to the Eustreptospondylidae. In 2003 Naish considered it a member of the
Allosauroidea Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four family (biology), families — the Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae. Allosauroids, alongside the family Megalosauroid ...
. Most researchers give a less precise placement as
Tetanurae Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans ar ...
''
incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...
''.M. T. Carrano, R. B. J. Benson, and S. D. Sampson, 2012, "The phylogeny of Tetanurae (Dinosauria: Theropoda)", ''Journal of Systematic Palaeontology'' 10(2): 211-300


References

{{Taxonbar, from=Q134618 Prehistoric neotheropods Valanginian life Early Cretaceous dinosaurs of Europe Cretaceous England Fossils of England Fossil taxa described in 1923 Taxa named by Friedrich von Huene