Cetiosaurus (/ˌsiːtioʊˈsɔːrəs, ˌsiːʃi-/) meaning 'whale lizard', from the Greek keteios/κήτειος meaning 'sea monster' (later, 'whale') and sauros/σαυρος meaning 'lizard', is a herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 167 million years ago in what is now Europe and Africa.
Cetiosaurus was in 1842 the first sauropod from which bones were described and is the most complete sauropod found in England. It was so named because its describer, Sir Richard Owen, supposed it was a marine creature, initially an extremely large crocodile, 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, 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. 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 16 metres (52 ft) long and to have weighed roughly 11 tonnes (12 short tons).
|Mounted skeleton, New Walk Museum|
Cetiosaurus was, 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. 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 but also in France, Switzerland and Morocco.
The first fossils, vertebrae and limb elements, were discovered near Chipping Norton 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, comparative anatomist and palaeontologist Sir Richard Owen, 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 oolithic layers. The first species was based on the material of Kingdon; the latter on vertebrae and metacarpals found at White Nab in Yorkshire. 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 of the former name.
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 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, "glymptonensis" to Glympton. Already in 1870 Thomas Huxley 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. 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 and anterior caudals, the chevrons, the ilium, the right femur, and rib and limb fragments.
The incomplete fossil is 15 metres (49 ft) long and has been displayed since 1985 in the New Walk Museum in Leicester. 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), 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.
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. In 2010, this was made a separate genus Duriatitan. In 1905, Arthur Smith Woodward renamed Ornithopsis leedsii Hulke 1887 into Cetiosaurus leedsi. This today is often considered a nomen dubium. In 1970 Rodney Steel 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, west of Boulogne-sur-Mer, in layers dating from the Tithonian. In 1903 however, he was forced to conclude it represented a pliosaurid. In 1880, Sauvage named another species: Cetiosaurus philippsi. In 1955, Albert-Félix de Lapparent named Cetiosaurus mogrebiensis based on three skeletons found in Morocco from the El Mers Formation dating to the Bathonian. The specific name refers to the Maghreb. 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 single Cetiosaurus species has been based on Swiss material. In 1932, Friedrich von Huene renamed Ornithopsis greppini Huene 1922 into Cetiosaurus greppini. This is today considered a nomen dubium.
In principle for every genus a type species must be indicated to serve as its type in an ostensive definition. Traditionally, C. medius had been considered the type species of Cetiosaurus. In 1888 Richard Lydekker had formally assigned C. oxoniensis as the type species but by the modern rules of the ICZN one of the species named by the original author, in this case Owen, must be selected. In 2003, Paul Upchurch 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. 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 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: "it is principally on these bones [i.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 only known from undiagnostic material. Its syntype series consists of eleven separate tail vertebrae, (specimina OUMNH J13693–13703), some sacral ribs with a foot bone (metatarsal, OUMNH J13704–13712), a hand bone (metacarpal, OUMNH J13748), and a claw (OUMNH J13721), probably from different fossil sites and different individuals.
The ICZN 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.
The complex naming history can be summarised in a list of Cetiosaurus species:
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) that was chosen by Upchurch & Martin as the lectotype 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 sixteen metres, the weight at eleven tonnes. 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. Its forearm was as long as the upper arm, unlike most other sauropods, resulting in a forelimb equalling the hindlimb in length. Its thigh bone 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 must be proven by indicating its new derived traits or autapomorphies. 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 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 was attached, features on the outer surface of its base a triangular depression.
Owen initially was unsure about the precise relationships of Cetiosaurus. He understood it was a reptile and most researchers at the time accordingly assigned it to the Sauria. 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 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. In 1861, Owen concentrated all such forms in a group of their own: the Opisthocoelia. In 1869 Thomas Huxley stated explicitly that Cetiosaurus was a dinosaur.
In 1888 Lydekker assigned Cetiosaurus to its own family: the Cetiosauridae. 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 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 uniting Cetiosaurus oxoniensis with species as the Indian Barapasaurus, the South American Patagosaurus or the African Chebsaurus. Other studies indicate that the traditional Cetiosauridae were paraphyletic and recover Cetiosaurus oxoniensis in a basal position in the Eusauropoda, basal in the Neosauropoda or just outside of this clade.
This cladogram shows a possible position of Cetiosaurus:
Cetiosaurus shared its time period with, and was possibly prey to Megalosaurus, possibly Streptospondylus and Cruxicheiros. The environment in which Cetiosaurus lived was floodplain and open woodland. Paul considered Cetiosaurus a feeding generalist, eating both at a low and a medium-high level, in view of its moderately long neck and limb proportions.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1841.Albert-Félix de Lapparent
Albert-Félix de Lapparent (1905–1975) was a French palaeontologist. He was also a Sulpician priest. He undertook a number of fossil-hunting explorations in the Sahara desert. He contributed greatly to our knowledge of dinosaurs and other prehistoric creatures. In 1986, José Bonaparte named the dinosaur Lapparentosaurus in his honour.
Dinosaurs named by Lapparent were Inosaurus tedreftensis (Lapparent, 1960) and Lusitanosaurus liassicus (Lapparent and Zbyszewski, 1957).
New species of known genera are also credited to him. In alphabetical order, they are: Apatosaurus alenquerensis (Lapparent and Zbyszewski, 1957), Astrodon pusillus (Lapparent and Zbyszewski, 1957), Brachiosaurus atalaiensis (Lapparent and Zbyszewski, 1957), Brachiosaurus nougaredi (Lapparent, 1960), Cetiosaurus mogrebiensis (Lapparent, 1955), Elaphrosaurus gautieri (Lapparent, 1960), Elaphrosaurus iguidiensis (Lapparent, 1960), Megalosaurus pombali (Lapparent and Zbyszewski, 1957) and Rebbachisaurus tamesnensis (Lapparent, 1960).
The giant crocodile Sarcosuchus was also discovered by him, in 1964.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.Cardiodon
Cardiodon (meaning "heart tooth", in reference to the shape) was a herbivorous genus of sauropod dinosaur, based on a tooth from the late Bathonian-age Middle Jurassic Forest Marble Formation of Wiltshire, England. Historically, it is very obscure and usually referred to Cetiosaurus, but recent analyses suggest that it is a distinct genus, and possibly related to Turiasaurus. Cardiodon was the first sauropod genus named.Cetiosauridae
Cetiosauridae is a family of sauropod dinosaurs. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural clade. Additionally, at least one study has suggested that the mamenchisaurids may represent a sub-group of the cetiosaurids, which would be termed Mamenchisaurinae.Cetiosauriscus
Cetiosauriscus ( SEE-tee-oh-SOR-iss-kəs) is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian (Middle Jurassic Period) in what is now England. A herbivore, Cetiosauriscus had—for sauropod standards—a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. It has been estimated as about 15 m (49 ft) long and between 4 and 10 t (3.9 and 9.8 long tons; 4.4 and 11.0 short tons) in weight.
The only known fossil that was later named Cetiosauriscus includes most of the rear half of a skeleton as well as a hindlimb (NHMUK R3078). Found in Cambridgeshire in the 1890s, it was described by Arthur Smith Woodward in 1905 as a new specimen of the species Cetiosaurus leedsi. This was changed in 1927, when Friedrich von Huene found NHMUK R3078 and the C. leedsi type specimen to be too different from Cetiosaurus, warranting its own genus, which he named Cetiosauriscus, meaning "Cetiosaurus-like". Cetiosauriscus leedsi was referred to the sauropod family Diplodocidae because of similarities in the tail and foot, and had the dubious or intermediate species "Cetiosauriscus" greppini, "C." longus, and "C." glymptonensis assigned to it. In 1980, Alan Charig named a new species of Cetiosauriscus for NHMUK R3078 because of the lack of comparable material to the type of C. leedsi; this species was named Cetiosauriscus stewarti. Because of the poor state of preservation of the Cetiosauriscus leedsi fossil, Charig sent a petition to the International Commission on Zoological Nomenclature to instead make C. stewarti the type species. Cetiosauriscus stewarti became the oldest confirmed diplodocid until a phylogenetic analysis published in 2003 instead found the species to belong to Mamenchisauridae, and followed by studies in 2005 and 2015 that found it outside Neosauropoda, while not a mamenchisaurid proper.
Cetiosauriscus was found in the marine deposits of the Oxford Clay Formation alongside many different invertebrate groups, marine ichthyosaurs, plesiosaurs and crocodylians, a single pterosaur, and various dinosaurs: the ankylosaur Sarcolestes, the stegosaurs Lexovisaurus and Loricatosaurus, the ornithopod Callovosaurus, as well as some unnamed taxa. The theropods Eustreptospondylus, Metriacanthosaurus and Megalosaurus are known from the formation, although probably not from the same level as Cetiosauriscus.Duriatitan
Duriatitan is a genus of titanosauriform sauropod dinosaur that lived in the Late Jurassic in what is now England. The holotype specimen of Duriatitan, BMNH 44635, is a partial left upper arm bone which was found by R.I. Smith near Sandsfoot in the lower Kimmeridge Clay from Dorset. The type species, D. humerocristatus, was described in 1874 by John Hulke as a species of Cetiosaurus. The specific name refers to the deltopectoral crest, crista, on the upper arm bone, humerus. The specimen was assigned to its own genus by Paul M. Barrett, Roger B.J. Benson and Paul Upchurch in 2010. The generic name is derived from the Latin name for Dorset, Duria, and Greek Titan.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 Barapasaurus, and Amygdalodon, but excluding Vulcanodon and Rhoetosaurus. The Eusauropoda was coined in 1995 by Paul Upchurch to create a monophyletic new taxonomic group that would include all sauropods, except for the vulcanodontids.Eusauropoda are herbivorous, quadrupedal, and have long necks. They have been found in South America, Europe, North America, Asia, Australia, and Africa. The temporal range of Eusauropoda ranges from the early Jurassic to the Latest Cretaceous periods. The most basal forms of eusauropods are not well known and because the cranial material for the Vulcanodon is not available, and the distribution of some of these shared derived traits that distinguish Eusauropoda is still completely clear.Forest Marble Formation
The Forest Marble is a geological formation in England. Part of the Great Oolite Group, it dates to back to the late Bathonian stage of the Middle Jurassic.Great Oolite
The Great Oolite is a geological formation in Europe. It dates back to the Middle Jurassic.Great Oolite Group
The Great Oolite Group is a Middle Jurassic stratigraphic unit that outcrops in southern England. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the unit.Haplocanthosaurus
Haplocanthosaurus (meaning "simple spined lizard") is a genus of intermediate sauropod dinosaur. Two species, H. delfsi and H. priscus, are known from incomplete fossil skeletons. It lived during the late Jurassic period (Kimmeridgian stage), 155 to 152 million years ago. The type species is H. priscus, and the referred species H. delfsi was discovered by a young college student named Edwin Delfs in Colorado, USA. Haplocanthosaurus specimens have been found in the very lowest layer of the Morrison Formation, along with Hesperosaurus, Brontosaurus yahnahpin, and Allosaurus jimmadensi.Ichnite
An ichnite (Greek "ιχνιον" (ichnion) – a track, trace or footstep) is a fossilised footprint. This is a type of trace fossil. Over the years, many ichnites have been found, around the world, giving important clues about the behaviour (and foot structure and stride) of the animals that made them. For instance, multiple ichnites of a single species, close together, suggest 'herd' or 'pack' behaviour of that species.
Combinations of footprints of different species provide clues about the interactions of those species. Even a set of footprints of a single animal gives important clues, as to whether it was bipedal or quadrupedal. In this way, it has been suggested that some pterosaurs, when on the ground, used their forelimbs in an unexpected quadrupedal action.
Special conditions are required, in order to preserve a footprint made in soft ground (such as an alluvial plain or a formative sedimentary deposit). A possible scenario is a sea or lake shore that became dried out to a firm mud in hot, dry conditions, received the footprints (because it would only have been partially hardened and the animal would have been heavy) and then became silted over in a flash storm.
The first ichnite found was in 1800 in Massachusetts, USA, by a farmer named Pliny Moody, who found 1-foot (31 cm) long fossilized footprints. They were thought by Harvard and Yale scholars to be from "Noah's Raven." A famous group of ichnites was found in a limestone quarry at Ardley, 20 km Northeast of Oxford, England, in 1997. They were thought to have been made by Megalosaurus and possibly Cetiosaurus. There are replicas of some of these footprints, set across the lawn of Oxford University Museum of Natural History (OUMNH).
A creature named Cheirotherium was, for a long time and still may be, only known from its fossilised trail. Its footprints were first found in 1834, in Thuringia, Germany, dating from the Late Triassic Period.
The largest known dinosaur footprints, belonging to sauropods and dating from the early Cretaceous were found to the north of Broome on the Dampier Peninsula, Western Australia, with some footprints measuring 1.7m.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 ancestor. The group is composed of two subgroups: Diplodocoidea and Macronaria. Arising in the early Jurassic and persisting until the Cretaceous-Paleogene extinction event, Neosauropoda contains the majority of sauropod genera, including genera such as Apatosaurus, Brachiosaurus, and Diplodocus. It also includes giants such as Argentinosaurus, Patagotitan and Sauroposeidon, and its members remain the largest land animals ever to have lived.When Bonaparte first coined the term Neosauropoda in 1986, he described the clade as comprising “end-Jurassic” sauropods. While Neosauropoda does appear to have originated at the end of the Jurassic period, it also includes members through the end of the Cretaceous. Neosauropoda is currently delineated by specific shared, derived characteristics rather than the time period in which its members lived. The group was further refined by Upchurch, Sereno, and Wilson, who have identified thirteen synapomorphies shared among neosauropods. As Neosauropoda is a subgroup of Sauropoda, all members also display basic sauropod traits such as large size, long necks, and columnar legs.Ornithopsis
Ornithopsis (meaning "bird-likeness") was a medium-sized Early Cretaceous sauropod dinosaur, from England.Patagosaurus
Patagosaurus (meaning "Patagonia lizard") is an extinct genus of eusauropodan dinosaur from the Middle Jurassic of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 165 to 161 million years ago. Although originally twelve specimens were assigned to the taxon, at least one of them may belong to a different genus. Patagosaurus probably lived alongside genera as Piatnitzkysaurus, Condorraptor, and Volkheimeria.
Since Patagosaurus is known from many specimens, including at least one juvenile, its anatomy and growth are fairly well understood. Both ages exhibit the typical features of a sauropod, a long neck, small head, a long tail, and being quadrupedal. The juvenile exhibits features different from the adult in regions like the mandible, pectoral girdle, pelvis and hindlimb, although overall their anatomy is quite similar. The many known specimens help fill in gaps in the anatomy of the genus, such as the forelimb and skull. Parts of the skeleton, like the pectoral girdle, tibia, and pubis are more robust, while others, like the forelimb and ischium, are more gracile. The material of Patagosaurus is similar to closely related taxa like Cetiosaurus and Volkheimeria, more primitive genera such as Barapasaurus and Amygdalodon, and more derived sauropods like Diplodocus and Camarasaurus.Pelorosaurus
Pelorosaurus ( pə-LORR-oh-SOR-əs; 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 Portugal.
The name Pelorosaurus was one of the first to be given to any sauropod. Many species have been assigned to the genus historically, but most are currently considered to belong to other genera. Problematically, the first named species of Pelorosaurus, P. conybeari, is a junior synonym of Cetiosaurus brevis.Sauropoda
Sauropoda ( or ), or the sauropods (; sauro- + -pod, "lizard-footed"), are a clade of saurischian ("lizard-hipped") dinosaurs. They had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Brachiosaurus, Diplodocus, Apatosaurus, Brontosaurus, and Mamenchisaurus.Sauropods first appeared in the late Triassic Period, where they somewhat resembled the closely related (and possibly ancestral) group "Prosauropoda". By the Late Jurassic (150 million years ago), sauropods had become widespread (especially the diplodocids and brachiosaurids). By the Late Cretaceous, those groups had mainly been replaced by the titanosaurs, which had a near-global distribution. However, as with all other non-avian dinosaurs alive at the time, the titanosaurs died out in the Cretaceous–Paleogene extinction event. Fossilised remains of sauropods have been found on every continent, including Antarctica.The name Sauropoda was coined by O.C. Marsh in 1878, and is derived from Greek, meaning "lizard foot". Sauropods are one of the most recognizable groups of dinosaurs, and have become a fixture in popular culture due to their impressive size.
Complete sauropod fossil finds are rare. Many species, especially the largest, are known only from isolated and disarticulated bones. Many near-complete specimens lack heads, tail tips and limbs.Shunosaurus
Shunosaurus, meaning "shu lizard", is a genus of sauropod dinosaur from Early Jurassic (Oxfordian) beds in Sichuan Province in China, approximately 159±2 million years ago. The name derives from "Shu", an ancient name for the Sichuan province.