''Syngonosaurus'' is an extinct

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 n ...

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous worl ...

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 (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

. It was an

iguanodontia Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', '' Dryosaurus'', '' Iguanodon'', '' Tenontosaurus'', and the hadrosaurids or "duck- ...

n discovered in

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 ...

and was first described in 1879. 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( ...

, ''S. macrocercus'', was described by British

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of foss ...

Harry Seeley Harry Govier Seeley (18 February 1839 – 8 January 1909) was a British paleontologist. Early life Seeley was born in London on 18 February 1839, the second son of Richard Hovill Seeley, a goldsmith, and his second wife Mary Govier. When his fat ...

in 1879 and it was later synonymised with ''

Acanthopholis ''Acanthopholis'' (; meaning "spiny scales") 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. History Around 1865 commercial fos ...

'', but the genus was reinstated in a 2020 study, when ''Syngonosaurus'' and '' Eucercosaurus'' were reinterpreted as basal

ns.

History

In 1869

Harry Govier Seeley Harry Govier Seeley (18 February 1839 – 8 January 1909) was a British paleontologist. Early life Seeley was born in London on 18 February 1839, the second son of Richard Hovill Seeley, a goldsmith, and his second wife Mary Govier. When his fat ...

named several new species of ''

'' based on remains from the

Cambridge Greensand The Cambridge Greensand is a geological unit in England whose strata are earliest Cenomanian in age. It lies above the erosive contact between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the lo ...

: ''Acanthopholis macrocercus'', based on specimens CAMSM B55570-55609; ''Acanthopholis platypus'' (CAMSM B55454-55461); and ''Acanthopholis stereocercus'' (CAMSM B55558 55569). Later, Seeley split the material of ''Acanthopholis stereocercus'' and based a new species of ''

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 ei ...

'' on part of it: ''Anoplosaurus major''. He also described a new species, ''Acanthopholis eucercus'', on the basis of six caudal vertebrae (CAMSM 55552-55557). In 1902 however

Franz Nopcsa Franz may refer to: People * Franz (given name) * Franz (surname) Places * Franz (crater), a lunar crater * Franz, Ontario, a railway junction and unorganized town in Canada * Franz Lake, in the state of Washington, United States – see Fran ...

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 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 ...

renamed ''A. platypus'' into ''

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 England. The type species, ''M. semnus'', was named in 1876. A second speci ...

platypus''. In 1999 Xabier Pereda-Superbiola and Paul M. Barrett reviewed all ''Acanthopholis'' material. They concluded that all species were ''

nomina dubia 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 ...

'' whose syntype specimens were composites of non-diagnostic ankylosaur and ornithopod remains; including ''Syngonosaurus''. ''Syngonosaurus'' was seen as an ankylosaur in both a 2001 publication and a 2004 publication.M. K. Vickaryous, T. Maryanska, and D. B. Weishampel. 2004. Ankylosauria. In D. B. Weishampel, P. Dodson, and H. Osmolska (eds.), ''

The Dinosauria ''The Dinosauria'' is an extensive book on dinosaurs, compiled by David B. Weishampel, Peter Dodson, and Halszka Osmólska. It has been published in 2 editions, with the first edition published in 1990, consisting of material from 23 scientists.Be ...

'' ( second edition). University of California Press, Berkeley 363-392 ''Syngonosaurus'' was synonymised with ''Acanthopholis'' in 1999, but the genus was reinstated in a 2020 study, when ''Syngonosaurus'' and '' Eucercosaurus'' were reinterpreted as basal

ns.

References

{{Taxonbar, from=Q5674171 Ornithopods Albian life Early Cretaceous dinosaurs of Europe Cretaceous England Fossils of England Fossil taxa described in 1879 Taxa named by Thomas Henry Huxley Ornithischian genera