''Agrosaurus'' (; perhaps from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''agros'' meaning 'field' and ''sauros'' meaning 'lizard', "field lizard") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of thecodontosaurid

sauropodomorph Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lon ...

probably originating from

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 b ...

that was originally believed to be a

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

prosauropod Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lon ...

from

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. ''Agrosaurus'' would thus be the oldest

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 that country. However, this appears to have been an error, and the material actually appears to come from ''

Thecodontosaurus ''Thecodontosaurus'' ("socket-tooth lizard") is a genus of herbivorous basal sauropodomorph dinosaur that lived during the late Triassic period (Rhaetian age). Its remains are known mostly from Triassic "fissure fillings" in South England. ''The ...

'' or a ''Thecodontosaurus''-like animal from

Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

(

Avon Fissure Fill The Avon Fissure Fill, also known as the Bristol Fissure Fill or Tytherington Fissure Fill, is a fissure fill in Avon, England (now Bristol) which dates variously from the Norian and Rhaetian stages of the Late Triassic, or possibly as late as t ...

). 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 ...

is ''Agrosaurus macgillivrayi''.

History

Members of an expedition from the British

sloop-of-war In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns. The rating system covered all vessels with 20 guns and above; thus, the term ''sloop-of-war'' enc ...

HMS ''Fly'' supposedly collected two

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

e, a

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...

and two foot claws as well as some other fragments in 1844 while erecting a beacon on the coast of Cape York,

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

. The context of the discovery is uncertain, as it is not mentioned in books by expedition naturalist John MacGallivray, nor in a 1847 book on the voyage by geologist Joseph Beete-Jukes. The bones were probably instead collected during the

autumn Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Sou ...

of 1834 in the

Magnesian Conglomerate The Magnesian Conglomerate is a geological formation in Clifton, Bristol in England (originally Avon), Gloucestershire and southern Wales, present in Tytherington, Durdham Down and Cromhall Quarry. It dates back to the Rhaetian stage of the Late ...

by Henry Riley and

Samuel Stutchbury Samuel Stutchbury (15 January 1798 – 12 February 1859) was an English naturalist and geologist. Alongside Henry Riley, Stutchbury was the co-discoverer of ''Thecodontosaurus'', which in 1836 was the fourth dinosaur genus to be named. He also p ...

. The original block was purchased by the

British Museum of Natural History The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum an ...

in 1879, from Edward Charlesworth selling the collection of the late Samuel Long Waring, and given the inventory number BMNH 49984, but the remains were not studied until 1891.

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 ...

in that year named it ''Agrosaurus macgillivrayi'', not giving an

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

. Seeley. H. G. (1891). On ''Agrosaurus macgillivrayi'' (Seeley), a saurischian reptile from the N.E. coast of Australia. ''Quarterly Journal of the Geological Society of London'' 47:164-165 The block was prepared in the late 1980s, the bones being freed from the matrix by an acid bath. Following the preparation, Ralph Molnar (1991) noticed similarities to the basal sauropodomorph ''

Massospondylus ''Massospondylus'' ( ; from Greek, (massōn, "longer") and (spondylos, "vertebra")) is a genus of sauropodomorph dinosaur from the Early Jurassic. (Hettangian to Pliensbachian ages, ca. 200–183 million years ago). It was described by S ...

''. Galton and Cluver (1976) saw ''Agrosaurus'' as close to ''

Anchisaurus ''Anchisaurus'' is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Portland Formation, Northeastern United States, which was deposited from the Het ...

''. Vickers-Rich, Rich, McNamara and Milner (1999) equated ''Agrosaurus'' and ''

antiquus'', claiming that the British Museum remains were mislabelled. The

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

in which the bones were preserved was tested with rocks of similar age in Cape York and Durdham Downs, the latter being beds where ''Thecodontosaurus'' remains have been found in the Bristol area of England. The English beds compared most favourably. As early as 1906,

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 ...

had described the rock matrix as 'extremely reminiscent of the bone breccia at Durdham Downs near Bristol' and had renamed the species ''Thecodontosaurus macgillivrayi''. Remains of the jaw of a

sphenodont Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse gro ...

identical to ''

Diphydontosaurus ''Diphydontosaurus'' is an extinct genus of rhynchocephalian reptile from the Late Triassic of England and Italy. This small animal was related to the living tuatara (''Sphenodon''). It may have grown to a length of . It is more derived than ''G ...

avonis'', a lizard-like reptile common to the Bristol Triassic beds have been extracted. This reinterpretation of ''Agrosaurus'' as a misidentified British specimen has been accepted in later works. From the scant remains the living animal would appear to have been about three metres long (10 ft), with a typical basal

appearance: bulky body, long neck, small head and clawed feet. Like other basal

Sauropodomorpha Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lon ...

, it was probably mainly bipedal, running on its elongated hind legs. It was herbivorous or may have been an

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...

. The name ''Agrosaurus'' is now generally considered to be 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 ...

'' or a

junior 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, Linna ...

of ''Thecodontosaurus''. If ''Agrosaurus'' is not from Australia, which seems most probable, ''

Rhoetosaurus ''Rhoetosaurus'' (meaning "Rhoetos lizard"), named after Rhoetus, a titan in Greek Mythology, is a genus of sauropod dinosaur from the Jurassic ( Oxfordian) Walloon Coal Measures of what is now eastern Australia. ''Rhoetosaurus'' is estimated to ...

'' and ''

Ozraptor ''Ozraptor'' (meaning "Australian thief") is a genus of possibly abelisauroid theropod dinosaur from the Middle Jurassic (Bajocian) Colalura Sandstone of Australia, known from fragmentary remains. Discovery and naming In 1967 a group of four t ...

'', both from the

Bajocian In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratig ...

(

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

) would be the oldest known Australian dinosaurs. They are well documented.

References

External links

{{Taxonbar, from=Q2252557 Sauropodomorphs Rhaetian life Late Triassic dinosaurs of Europe Triassic England Fossils of England Fossil taxa described in 1891 Taxa named by Harry Seeley Nomina dubia

History

See also

References

Further reading

External links