HOME

TheInfoList



OR:

''Cetiosaurus'' () meaning 'whale lizard', from the
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 ...
'/ meaning 'sea monster' (later, 'whale') and '/ meaning 'lizard', 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 herbivorous
sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', ' lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their ...
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 Middle
Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...
Period, living about 168
million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago ...
in what is now
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
. ''Cetiosaurus'' was in 1842 the first sauropod from which bones were described and is the most complete sauropod found 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 ...
. It was so named because its describer, Sir
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 ...
, supposed it was a
marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...
creature, initially an extremely large
crocodile Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant me ...
, and did not recognise it for a land-dwelling dinosaur. Because of the early description many species would be named in the genus, eventually eighteen of them. Most of these have now been placed in other genera or are understood to be dubious names, based on poor fossil material. The last is true also of the original
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 specim ...
, ''Cetiosaurus medius'', and so ''C. oxoniensis'' was officially made the new type species in 2014. ''C. oxoniensis'' is based on three more or less complete specimens, discovered from 1868 onwards. Together they contain most of the bones, with the exception of the skull. ''Cetiosaurus oxoniensis'' was a "primitive", quadrupedal, long-necked, small-headed
herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
. It had a shorter tail and neck than most sauropods. The forelimbs on the other hand, were relatively long. ''C. oxoniensis'' is estimated to have been about long and to have weighed roughly .


Discovery and species


Initial finds

''Cetiosaurus'' is, with the exception of the tooth genus '' Cardiodon'', the first sauropod to be discovered and named as well as being the best known sauropod from England."Cetiosaurus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. ''The Age of Dinosaurs''. Publications International, LTD. p. 65. . Numerous species have been assigned to ''Cetiosaurus'' over the years belonging to several different groups of sauropod dinosaurs. The genus thus functioned as a typical " wastebasket taxon". Fossilized remains once assigned to ''Cetiosaurus'' have mainly been found 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 ...
but also in
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
,
Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
and
Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...
. The first fossils, vertebrae and limb elements, were discovered near
Chipping Norton Chipping Norton is a market town and civil parish in the Cotswold Hills in the West Oxfordshire district of Oxfordshire, England, about south-west of Banbury and north-west of Oxford. The 2011 Census recorded the civil parish population ...
in the early nineteenth century and were reported upon by collector John Kingdon in a letter read on 3 June 1825 to the Geological Society; they were seen as possibly belonging to a whale or crocodile. In 1841
biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual cell, a multicellular organism, or a community of interacting populations. They usually specialize ...
, comparative anatomist and
palaeontologist 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 ...
Sir
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 ...
, named these as the genus ''Cetiosaurus'', the year before he coined the term Dinosauria. Owen initially did not recognise ''Cetiosaurus'' for a dinosaur but considered it a gigantic sea-dwelling reptile. This was reflected by the name, derived from Greek κήτειος, ''kèteios'', "sea-monster". In 1842 Owen named two species in the genus: ''Cetiosaurus hypoolithicus'' and ''Cetiosaurus epioolithicus''. The specific names reflected whether the finds had been made below (hypo) or above (epi) the so-called
oolith Ooids are small (commonly ≤2 mm in diameter), spheroidal, "coated" (layered) sedimentary grains, usually composed of calcium carbonate, but sometimes made up of iron- or phosphate-based minerals. Ooids usually form on the sea floor, mo ...
ic layers. The first species was based on the material of Kingdon; the latter on vertebrae and metacarpals found at White Nab in
Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
. The publication did not contain a sufficient description and the species are often considered '' nomina nuda''. The same year in a subsequent publication Owen named four additional ''Cetiosaurus'' species: ''Cetiosaurus brevis'', "the short one"; ''Cetiosaurus brachyurus'', "the short-tailed"; ''Cetiosaurus medius'', "the medium-sized", and ''Cetiosaurus longus'', "the long one". Owen had abandoned the two earlier names, as shown by the fact that their fossils were referred to several of the new species. These again were each mostly based on disparate material, from often geographically widely separated sites. As became apparent in 1849, some of these bones were not sauropod in nature at all but of Iguanodontidae. That year Alexander Melville, in a misguided attempt to clear matters up, named the authentic sauropod material of ''C. brevis'' as ''Cetiosaurus conybeari'' but thereby merely created a
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 ...
of the former name.


''Cetiosaurus oxoniensis''

In March 1868, workers near Bletchingdon discovered a sauropod right femur. Between March 1869 and June 1870 Professor John Phillips, further investigating the site, in a layer dating from the
Bathonian In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. ...
uncovered three skeletons and additional bone material. In 1871 based on these he named two species: ''Cetiosaurus oxoniensis'' (originally spelled ''Ceteosaurus Oxoniensis'') and ''Cetiosaurus glymptonensis''. "Oxoniensis" refers to
Oxford Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...
, "glymptonensis" to
Glympton Glympton is a village and civil parish on the River Glyme about north of Woodstock, Oxfordshire. The 2001 Census recorded the parish's population as 80. The village and church are owned by the Glympton Park estate. History Grim's Ditch in t ...
. Already in 1870
Thomas Huxley Thomas Henry Huxley (4 May 1825 – 29 June 1895) was an English biologist and anthropologist specialising in comparative anatomy. He has become known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution. The stori ...
had published a letter by Phillips in which the latter named a ''Cetiosaurus giganteus'' based on specimen OUMNH J13617, a left femur earlier found at Bletchingdon; as the letter did not contain a description, this is a ''nomen nudum''. A century later, a new ''C. oxoniensis'' specimen (LCM G468.1968) called the "Rutland Dinosaur" was discovered on 19 June 1968 by the driver of an excavating vehicle. It was found at the base of the
Rutland Formation The Rutland Formation is a geologic formation in England. It preserves fossils dating back to the late Bajocian to Bathonian stages in the Jurassic period, about 169 million years ago. It is the lateral equivalent of the Sharp's Hill Formation ...
dating to 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. Stra ...
. Staff from Leicester City Museums arrived on 20 June 1968. It was not confirmed that all the preserved material was collected. It is the most complete sauropod fossil, and one of the most complete specimens of a dinosaur, ever found in the United Kingdom. It was only in around 1980 that there was interest in the fossil. It took around four years to find the dinosaur bones. Of the about two hundred bones in a cetiosaurus, it has preserved a nearly complete cervical series (2–14), most of the dorsal vertebrae, a small part of the
sacrum The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part o ...
and anterior caudals, the
chevron Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * '' Eulithis testata'', a moth * Chevron (geology), a fold in rock la ...
s, the ilium, the right
femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates ...
, and rib and limb fragments. The incomplete fossil is long and has been displayed since 1985 in the Leicester Museum & Art Gallery. Only the more structurally-sound parts of the dinosaur are on display, with the more-fragile parts stored elsewhere. Much of what can be seen in the display is a representation (
replica A 1:1 replica is an exact copy of an object, made out of the same raw materials, whether a molecule, a work of art, or a commercial product. The term is also used for copies that closely resemble the original, without claiming to be identical. Al ...
), and not the actual dinosaur. The model's vertebral column seen on display has fourteen cervicals, ten dorsals, five sacrals and about fifty caudals. The dinosaur display was taken to London to be featured on the children's television programme ''
Blue Peter ''Blue Peter'' is a British children's television entertainment programme created by John Hunter Blair. It is the longest-running children's TV show in the world, having been broadcast since October 1958. It was broadcast primarily from BBC Te ...
''.


Later species

In 1874, John Whitaker Hulke named ''Cetiosaurus humerocristatus'', "with a crested humerus", based on specimen BMNH 44635, a humerus found that year at Sandsfoot near Weymouth in
Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , ...
. In 2010, this was made a separate genus '' Duriatitan''. In 1905,
Arthur Smith Woodward Sir Arthur Smith Woodward, FRS (23 May 1864 – 2 September 1944) was an English palaeontologist, known as a world expert in fossil fish. He also described the Piltdown Man fossils, which were later determined to be fraudulent. He is not relate ...
renamed ''Ornithopsis leedsii'' Hulke 1887 into ''Cetiosaurus leedsi''. This today is often considered a ''nomen dubium''. In 1970
Rodney Steel Rodney may refer to: People * Rodney (name) * Rodney (wrestler), American professional wrestler Places ;Australia * Electoral district of Rodney, a former electoral district in Victoria * Rodney County, Queensland ;Canada * Rodney, Ontario, a vi ...
renamed '' Cardiodon'' Owen 1841, based on a now lost tooth, into ''Cetiosaurus rugulosus'', "the wrinkled one". If the species were cogeneric to ''Cetiosaurus'', the name of the genus would however be ''Cardiodon'' as this name has priority. In 2003, Upchurch & Martin rejected the identity. In addition to the thirteen species based on British material, three were named by French researchers. In 1874, Henri-Émile Sauvage named ''Cetiosaurus rigauxi'' based on a vertebra found by Edouard Edmond Joseph Rigaux at
Le Portel Le Portel (; vls, Turbodingem) is a commune in the Pas-de-Calais department in the Hauts-de-France region of France. Geography Le Portel is a tourist, fishing and light industrial town situated about southwest of Boulogne town centre, at the ju ...
, west of
Boulogne-sur-Mer Boulogne-sur-Mer (; pcd, Boulonne-su-Mér; nl, Bonen; la, Gesoriacum or ''Bononia''), often called just Boulogne (, ), is a coastal city in Hauts-de-France, Northern France. It is a Subprefectures in France, sub-prefecture of the Department ...
, in layers dating from the
Tithonian In the geological timescale, the Tithonian is the latest age of the Late Jurassic Epoch and the uppermost stage of the Upper Jurassic Series. It spans the time between 152.1 ± 4 Ma and 145.0 ± 4 Ma (million years ago). It is preceded by ...
. In 1903 however, he was forced to conclude it represented a
pliosaurid Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous (Rhaetian to Turonian stages) of Australia, Europe, North America and South America. The family is more inclusive than the archetypal ...
. In 1880, Sauvage named another species: ''Cetiosaurus philippsi''. In 1955, Albert-Félix de Lapparent named ''Cetiosaurus mogrebiensis'' based on three skeletons found in
Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...
from the El Mers Formation dating to the Bathonian. The specific name refers to the
Maghreb The Maghreb (; ar, الْمَغْرِب, al-Maghrib, lit=the west), also known as the Arab Maghreb ( ar, المغرب العربي) and Northwest Africa, is the western part of North Africa and the Arab world. The region includes Algeria, ...
. This is today sometimes seen as a valid taxon, but one not belonging to ''Cetiosaurus''. In 2011, Eric Buffetaut e.a. referred a chevron found in the French Ardennes, specimen A775, to a ''Cetiosaurus'' sp. A ''Cetiosaurus'' species has been based on
Swiss Swiss may refer to: * the adjectival form of Switzerland *Swiss people Places * Swiss, Missouri *Swiss, North Carolina * Swiss, West Virginia *Swiss, Wisconsin Other uses * Swiss-system tournament, in various games and sports * Swiss Internation ...
material. In 1932,
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 ''
Ornithopsis ''Ornithopsis'' (meaning "bird-likeness") 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''. History of discovery Gideon Algernon Mantell descr ...
greppini'' Huene 1922 into ''Cetiosaurus greppini''. This is today considered 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 ...
''. In 2020, it was proposed to assigned ''C. greppini'' to the new genus '' Amanzia''.


The question of the type species

In principle for every genus a
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 specim ...
must be indicated to serve as its type in an
ostensive definition An ostensive definition conveys the meaning of a term by pointing out examples. This type of definition is often used where the term is difficult to define verbally, either because the words will not be understood (as with children and new speake ...
. Traditionally, ''C. medius'' had been considered the type species of ''Cetiosaurus''. 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 ...
had formally assigned ''C. oxoniensis'' as the type species but by the modern 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 ...
one of the species named by the original author, in this case Owen, must be selected. In 2003,
Paul Upchurch Paul may refer to: * Paul (given name), a given name (includes a list of people with that name) *Paul (surname), a list of people People Christianity *Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...
and John Martin determined that ''C.'' "hypoolithicus" and ''C.'' "epioolithicus" could not be used because they were ''nomina nuda''. Of the four species named in Owen's second 1842 article, ''C. brevis'', ''C. brachyurus'', ''C. longus'' and ''C. medius'', only ''C. brevis '' would not 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 ...
''. This they interpreted as implying that ''C. brevis'' was the type species. This conclusion, if correct, would cause considerable taxonomic instability, because the genus ''
Pelorosaurus ''Pelorosaurus'' ( ; meaning "monstrous lizard") 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 Po ...
'' had since been based on its fossils, and recognized as a totally different kind of sauropod. Therefore, Upchurch & Martin suggested to request the ICZN to change the type species into ''C. oxoniensis'', the best known species from the Middle Jurassic, which the genus ''Cetiosaurus'' had generally come to be identified with. However, in 2009, when their request was officially filed, Upchurch and Martin had changed their position. They acknowledged that being designated a ''nomen dubium'' does not prevent a species from having been made the type of a genus. Furthermore, they had identified a passage in the 1842 article in which Owen himself had already assigned ''C. medius'' as 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 specim ...
: "it is principally on these bones .e. those of ''C. medius'' with others subsequently discovered and in the collection of Mr. Kingdon, that the characters of the ''Cetiosaurus'' were first determined". Nevertheless, they still advocated a change in type because ''C. medius'' is known only from undiagnostic material. Its
syntype In biological nomenclature, a syntype is any one of two or more biological types that is listed in a description of a taxon where no holotype was designated. Precise definitions of this and related terms for types have been established as part of ...
series consists of eleven separate tail vertebrae, (specimina OUMNH J13693–13703), some sacral ribs with a foot bone (
metatarsal 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 me ...
, OUMNH J13704–13712), a hand bone (
metacarpal In human anatomy, the metacarpal bones or metacarpus form the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist, which forms the connection to the forearm. The metacarpal bones ar ...
, OUMNH J13748), and a claw (OUMNH J13721), probably from different fossil sites and different individuals. 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 ...
accepted the proposal to change the type species in 2014 (Opinion 2331), officially making ''C. oxoniensis'' the type species in place of the original ''C. medius''. Making ''C. oxoniensis'' the type species of ''Cetiosaurus'' secured the name ''Cetiosaurus'' for the animal with which it has been traditionally associated.


Valid Species

The complex naming history can be summarised in a list of ''Cetiosaurus'' species: *''Cetiosaurus oxoniensis'' Phillips, 1871:
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 specim ...
of ''Cetiosaurus''


Doubtful species

*''Cetiosaurus hypoolithicus'' Owen, 1841: ''nomen nudum'' *''Cetiosaurus epioolithicus'' Owen, 1841: ''nomen nudum'' *''Cetiosaurus brachyurus'' Owen, 1842: ''nomen dubium'' *''Cetiosaurus longus'' Owen, 1842: ''nomen dubium''; = ''Cetiosauriscus longus'' (Owen, 1842) McIntosh, 1990 *''Cetiosaurus medius'' Owen, 1842: ''nomen dubium'' *''Cetiosaurus giganteus'' Owen vide Huxley, 1870: ''nomen nudum'' *''Cetiosaurus philippsi'' Sauvage, 1880


Misassigned and reclassified species

*''
Cetiosaurus brevis ''Cetiosaurus'' () meaning 'whale lizard', from the Greek '/ meaning 'sea monster' (later, 'whale') and '/ meaning 'lizard', is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 168 million years ago in ...
'' Owen, 1842: non ''Cetiosaurus'', = ''Cetiosaurus conybeari'' Melville, 1849; = ''
Pelorosaurus ''Pelorosaurus'' ( ; meaning "monstrous lizard") 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 Po ...
conybearei'' (Melville, 1849) Mantell, 1850; = ''Pelorosaurus brevis'' (Owen, 1842) Huene, 1927 *'' Cetiosaurus glymptonensis'' Phillips, 1871: non ''Cetiosaurus''; = ''Cetiosauriscus glymptonensis'' (Phillips, 1871) McIntosh, 1990, non ''Cetiosauriscus'' *'' Cetiosaurus rigauxi'' Sauvage, 1874: non ''Cetiosaurus'', pliosaurid *'' Cetiosaurus humerocristatus'' Hulke, 1874: non ''Cetiosaurus''; = ''Ornithopsis humerocristatus'' (Hulke, 1874) Lydekker, 1889; = ''Pelorosaurus humerocristatus'' (Hulke, 1874) Sauvage, 1897; = '' Duriatitan humerocristatus'' (Hulke, 1874) Barrett, Benson & Upchurch, 2010 *'' Cetiosaurus leedsi'' (Hulke, 1887) Woodward, 1905: ''nomen dubium''; = ''Ornithopsis leedsii'' Hulke, 1887 *'' Cetiosaurus greppini'' (Huene, 1922) Huene, 1932: ''nomen dubium'', = ''Ornithopsis greppini'' Huene, 1922 = '' Amanzia greppini'' (Huene, 1922) Schwarz ''et al.'', 2020 *'' Cetiosaurus rugulosus'' (Owen, 1845) Steel, 1970: non ''Cetiosaurus'', = '' Cardiodon'' Owen, 1841; = ''Cardiodon rugulosus'' Owen, 1845 *'' Cetiosaurus mogrebiensis'' de Lapparent, 1955: non ''Cetiosaurus''


Description

''Cetiosaurus'', or specifically the neotype species ''C. oxoniensis'', is known from relatively complete fossils. These include the three skeletons found by Phillips. One of these is a larger animal (catalogued as OUMNH J13605–13613, J13615–16, J13619–J13688 and J13899), which was chosen by Upchurch & Martin as the
lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...
of the species; the second consists of limb bones of a smaller individual (OUMNH J13614) and the third skeleton represents the shoulder blade and hindlimb of a juvenile animal (OUMNNH J13617–8, J13780–1). The Rutland specimen, about 40% complete, increases considerably the number of known skeletal elements, especially in the neck. The skull is largely unknown, perhaps with the exception of the brain case represented by specimen OUMNH J13596. A single tooth crown, OUMNH J13597, has provisionally been referred to the species. ''Cetiosaurus'' was, as any sauropod, a long-necked quadrupedal animal. In 2010, Gregory S. Paul estimated the body length at and body mass at .Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 177 Its neck was moderately long; no longer than its body. The tail was considerably longer, consisting of at least forty caudal vertebrae. Its dorsal vertebrae, the bones along the back, had the original heavy build with limited air chambers, unlike the extremely hollowed-out bones of later sauropods like ''
Brachiosaurus ''Brachiosaurus'' () is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154to 150million years ago. It was first Species description, described by American paleontologist Elmer S. Riggs in 1903 in pal ...
''. Its forearm was as long as the
upper arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between t ...
, unlike most other sauropods, resulting in a forelimb equalling the hindlimb in length. Its
thigh bone The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
was approximately six feet long. In his original descriptions, Owen was unable to indicate any differences between ''Cetiosaurus'' and other sauropods for the simple reason these latter were not yet discovered. Now that such relatives have been found, the uniqueness of ''Cetiosaurus oxoniensis'' and its status as a valid
taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...
must be proven by indicating its new derived traits or
autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...
. In their 2003 revision of the genus, Upchurch & Martin identified five autapomorphies of ''C. oxoniensis''. The rear neck vertebrae and the front back vertebrae have spines on their tops that are low, symmetrical and in the shape of a pyramid. With the spines of all back vertebrae a ridge is absent between the spine and the diapophysis, the top rib joint; it has been lost or perhaps fused with the ridge running between the spine and the
postzygapophysis The articular processes or zygapophyses (Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "process") of a vertebra are projections of the vertebra that serve the purpose of fitting with an adjacent vertebr ...
, the rear joint process. The vertebrae of the middle tail have a tongue-shaped process at the top of the front face of the vertebral body; this is an extension of the floor of the neural canal. The chevrons of the front tail vertebrae have shafts of which the lower ends are flattened from the front to the rear instead of transversely. The lower process of the ilium, to which the
pubic bone In vertebrates, the pubic region ( la, pubis) is the most forward-facing ( ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ...
was attached, features on the outer surface of its base a triangular depression.


Classification and phylogeny

Owen initially was unsure about the precise relationships of ''Cetiosaurus''. He understood it was a
reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
and most researchers at the time accordingly assigned it to the
Sauria Sauria is the clade containing the most recent common ancestor of archosaurs (such as crocodilians, dinosaurs, etc.) and lepidosaurs ( lizards and kin), and all its descendants. Since most molecular phylogenies recover turtles as more closely ...
. However, he at first did not recognise its dinosaurian nature; when in 1842 he named the Dinosauria, ''Cetiosaurus'' was not included. This was influenced by the preconception that such a large animal must have been sea-dwelling. Owen assumed crocodylian affinities. In the early 1850s,
Gideon Mantell Gideon Algernon Mantell MRCS FRS (3 February 1790 – 10 November 1852) was a British obstetrician, geologist and palaeontologist. His attempts to reconstruct the structure and life of ''Iguanodon'' began the scientific study of dinosaurs: in ...
began to suspect that ''Cetiosaurus'' was a land animal as a result of his studies of ''Pelorosaurus''. This idea however, was only slowly accepted by other scientists. In 1859 Owen still classified ''Cetiosaurus'' in the
Crocodylia Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period (Cenomanian stage) and are the closest living ...
. In 1861, Owen concentrated all such forms in a group of their own: the Opisthocoelia. In 1869
Thomas Huxley Thomas Henry Huxley (4 May 1825 – 29 June 1895) was an English biologist and anthropologist specialising in comparative anatomy. He has become known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution. The stori ...
stated explicitly that ''Cetiosaurus'' was a dinosaur. In 1888 Lydekker assigned ''Cetiosaurus'' to its own family: the
Cetiosauridae Cetiosauridae is a family of sauropod dinosaurs which was first proposed by Richard Lydekker in 1888. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural cl ...
. For a long time this functioned as a large ill-defined family of typically "primitive" sauropods. Today however, many considerably more basal sauropods than ''Cetiosaurus'' are known. Modern exact
cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...
research has not resulted in a single clear outcome about the position of ''Cetiosaurus oxoniensis'' in the sauropod tree. Sometimes a Cetiosauridae was recovered, a
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
uniting ''Cetiosaurus oxoniensis'' with species as the Indian ''
Barapasaurus ''Barapasaurus'' ( ) is a genus of basal sauropod dinosaur from Early Jurassic rocks of India. The only species is ''B. tagorei''. ''Barapasaurus'' comes from the lower part of the Kota Formation, that dates back to the Sinemurian and Pliensb ...
'', the South American ''
Patagosaurus ''Patagosaurus'' (meaning "Patagonia lizard") is an extinct genus of eusauropod dinosaur from the Middle-Late Toarcian of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 179 to 177&n ...
'' or the African ''
Chebsaurus ''Chebsaurus'' is a genus of quadrupedal, herbivorous, cetiosaurid sauropod dinosaur, specifically a eusauropod. It lived in present-day Algeria, in the Callovian aged Aïssa Formation. The type species, ''C. algeriensis'', was named in 2 ...
''. Other studies indicate that the traditional Cetiosauridae were
paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...
and recover ''Cetiosaurus oxoniensis'' in a basal position in the
Eusauropoda Eusauropoda (meaning "true sauropods") is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of ''Shunosaurus'', and possibly ''Barapasau ...
, basal in the
Neosauropoda Neosauropoda is a clade within Dinosauria, coined in 1986 by Argentine paleontologist José Bonaparte and currently described as '' Saltasaurus loricatus'', '' Diplodocus longus'', and all animals directly descended from their most recent common ...
or just outside of this clade.D.T. Ksepka and M.A. Norell, 2010, "The Illusory Evidence for Asian Brachiosauridae: New Material of ''Erketu ellisoni'' and a Phylogenetic Reappraisal of Basal Titanosauriformes", ''American Museum Novitates'' 3700: 1-27


Paleobiology

''Cetiosaurus'' shared its time period with, and was possibly prey to ''
Megalosaurus ''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 ...
'', possibly ''
Streptospondylus ''Streptospondylus'' (meaning "reversed vertebra") is a genus of tetanuran theropod dinosaur known from the Late Jurassic period of France, 161 million years ago. It was a medium-sized predator with an estimated length of 6 meters (19.5&nb ...
'' and ''
Cruxicheiros ''Cruxicheiros'' (meaning "cross hand") is a genus of theropod dinosaur which lived in the Middle Jurassic of England. The type species is ''C. newmanorum'', described by Roger Benson and Jonathan Radley in 2010. Discovery The remains of t ...
''. The environment in which ''Cetiosaurus'' lived was
floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
and open woodland. Paul considered ''Cetiosaurus'' a feeding generalist, eating at both a low and a medium-high level, in view of its moderately long neck and limb proportions.


References


Bibliography

* *Owen, R. 1842. Second rapport sur les reptiles fossiles de la Grande-Bretagne. L’Institut, Journal général des Sociétés et Travaux Scientifique de la France et de l’ Étranger
10: 11–14
on Google Books. *Owen, R. 1875. Monograph of the Mesozoic Reptilia, part 2: Monograph on the genus Cetiosaurus. Palaeontolographical Society Monograph, 29: 27–43. {{Taxonbar, from=Q14427 Cetiosauridae Bathonian life Middle Jurassic dinosaurs of Europe Jurassic England Fossils of England Middle Jurassic dinosaurs of Africa Jurassic Morocco Fossils of Morocco Fossil taxa described in 1841 Taxa named by Richard Owen