{{Otheruses}}{{pp-semi-protected|small=yes}}{{Otheruses}}{{pp-semi-protected|small=yes}}
{{Taxobox
| name = Sauropods
| fossil_range =
Early JurassicThe Early Jurassic epoch The Early Jurassic epoch The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series is the earliest of three epochs of the Jurassic period...
–
Late CretaceousThe Late Cretaceous is the youngest of two epochs in which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
, {{Fossilrange|188|66}}
| image = Diplodocus carnegiei.jpg
| image_width = 250px
| image_caption = Mounted skeleton (cast) of
Diplodocus carnegieiDiplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones located in...
at the Museum für Naturkunde Berlin
| regnum =
AnimalAnimals are a major group of mostly multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously...
ia
| phylum =
ChordataChordates are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail...
| classis =
ReptiliaReptiles, or members of the class Reptilia, are air-breathing, generally "cold-blooded" amniotes that generally have skin covered in scales or scutes. They are tetrapods and lay amniote eggs, whose embryos are surrounded by the amnion membrane...
| superordo =
Dinosaur{{Otheruses}}{{pp-semi-protected|small=yes}}{{Otheruses}}{{pp-semi-protected|small=yes}}{{Taxobox|name = Dinosaurs|fossil_range = {{Fossil range|230|65|earliest=230|latest=0|PS=
Descendant taxon Aves survives to present.}}|image = field_dinos_2.jpg...
ia
| ordo =
SaurischiaSaurischia is one of the two orders, or basic divisions, of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two orders, based on their hip structure...
| subordo = †
SauropodomorphaThe Sauropodomorpha were a group of long-necked, herbivorous dinosaurs that eventually dropped down on all fours and became the largest animals that ever walked the earth.- Description :...
| infraordo =
†In biology and ecology, extinction is the end of an organism or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species...
Sauropoda
| infraordo_authority =
MarshOthniel Charles Marsh was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West.-Early life:...
, 1878
| subdivision_ranks =
FamiliesIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
| subdivision =
See text.
}}
Sauropoda ({{pron-en|sɔːˈrɒpədə}}), or the
sauropods ({{IPA|/ˈsɔrɵpɒd/}}), are an
infraorderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
or
cladeA clade is a term used in modern alpha taxonomy, the scientific classification of living and fossil organisms, to describe a monophyletic group, defined as a group consisting of a single common ancestor and all its descendants.[The term "monophyletic group" is used in this article...]
of
saurischiaSaurischia is one of the two orders, or basic divisions, of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two orders, based on their hip structure...
n ("lizard-hipped")
dinosaur{{Otheruses}}{{pp-semi-protected|small=yes}}{{Otheruses}}{{pp-semi-protected|small=yes}}{{Taxobox|name = Dinosaurs|fossil_range = {{Fossil range|230|65|earliest=230|latest=0|PS=
Descendant taxon Aves survives to present.}}|image = field_dinos_2.jpg...
s. They are notable for the enormous sizes attained by some species, and the group includes many of the largest animals to have ever lived on land. Well-known
generaIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
include
ApatosaurusApatosaurus , including the popular but obsolete synonym Brontosaurus, is a genus of sauropod dinosaur that lived about 150 million years ago, during the Jurassic Period . It was one of the largest land animals that ever existed, with an average length of 23 m and a mass of at least 23 metric tons...
(formerly known as
Brontosaurus),
BrachiosaurusBrachiosaurus , meaning "arm lizard", from the Greek brachion/βραχιων meaning "arm" and sauros/σαυρος meaning "lizard", was a genus of sauropod dinosaur that lived during the Late Jurassic Period and possibly the Early Cretaceous Period. It was named thus because its forelimbs were longer than its...
and
DiplodocusDiplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones located in...
. Sauropods first appeared in the late
TriassicThe Triassic is a geologic period and system that extends from about 251 to 199 Ma . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
Period, where they somewhat resembled the closely related (and possibly ancestral) group
ProsauropodaProsauropoda or prosauropods were a group of early herbivorous dinosaurs that lived during the Triassic and early Jurassic periods. They were frequently the predominant herbivore in their environment, and quickly reached large size, from...
. By the
Late JurassicThe Late Jurassic epoch of the Jurassic Period is the unit of geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago, which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name Malm indicates rocks of Late Jurassic age...
(150 million years ago), sauropods were widespread (especially the diplodocids and brachiosaurids). By the
Late CretaceousThe Late Cretaceous is the youngest of two epochs in which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
, those groups had mainly been replaced by the
titanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus...
s, which had a near-global distribution. However, as with all other non-avian dinosaurs, the titanosaurs died out in the Cretaceous–Tertiary extinction event.
FossilFossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record...
ised remains of sauropods have been found on every continent, including
Antarctica| style="border-top:solid 1px #ccd2d9; padding:0.4em 1em 0.4em 0; vertical-align:top;" | 14,000,000 km
2 280,000 km
2 13,720,000 km
2 |-! style="border-top: solid 1px #ccd2d9; padding: 0.4em 1em 0.4em 0; vertical-align: top;...
.
The name Sauropoda was coined by O.C. Marsh in 1878, and is derived from the
GreekAncient Greek is the historical stage in the development of the Greek language spanning across the Archaic , Classical , and Hellenistic periods of ancient Greece and the ancient world. It is predated in the 2nd millennium BC by Mycenaean Greek...
for "lizard foot".
Complete fossil sauropod 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.
Description
Sauropods were herbivorous (plant-eating), usually long-necked
quadrupedQuadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
s (four-legged), with spatulate (spatula-shaped: broad at the base, narrow at the neck) teeth. They had small heads, huge bodies, and tended to have long tails. Their legs were thick, ending in blunt feet with five toes, though only three bore claws.
Size
Sauropods' most defining characteristic was their size. Even the dwarf sauropods like
EuropasaurusEuropasaurus is a basal macronarian sauropod, a form of quadrapedal herbivorous dinosaur. It lived during the Upper Jurassic of northern Germany, and has been identified as an example of insular dwarfism resulting from the isolation of a sauropod population on an island within the Lower Saxony...
(perhaps 5 to 6
metreThe metre or meter is the basic unit of length in the International System of Units . Historically, the metre was defined by the French Academy of Sciences as the length between two marks on a platinum-iridium bar, which was designed to represent one ten-millionth of the distance from the Equator...
s, or 20 feet long) were counted among the largest animals in their
ecosystemAn ecosystem is a system of interdependent organisms which share the same habitat, in an area functioning together with all of the physical factors of the environment. Ecosystems can be permanent or temporary. Ecosystems usually form a number of food webs...
. Their only real competitors in terms of size are the
rorqualRorquals are the largest group of baleen whales, with nine species in two genera. They include the largest animal that has ever lived, the Blue Whale, which can reach , and two others that easily pass ; even the smallest of the group, the Northern Minke Whale, reaches .-Characteristics:Rorquals...
whaleWhale is the common name for marine mammals of the order Cetacea. The term whale is sometimes used to refer to all cetaceans, but in more common English usage it generally excludes the members of the Delphinoidea superfamily, such as dolphins and porpoises...
s, such as the
Blue WhaleThe Blue Whale is a marine mammal belonging to the suborder of baleen whales . At up to in length and or more in weight, it is the largest animal ever known to have existed....
. But unlike whales, sauropods all lived on land. Some, like the
diplodocidDiplodocids, or members of the family Diplodocidae , are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the earth, including Diplodocus and Supersaurus, which may have reached lengths of up to 34 m , and the gigantic Amphicoelias, known from a single...
s, probably held their heads low, while others, like
CamarasaurusCamarasaurus meaning 'chambered lizard', referring to the holes in its vertebrae was a genus of quadrupedal, herbivorous dinosaurs...
, held them high.
Their body design did not vary as much as other dinosaurs, perhaps due to size constraints, but they still displayed ample variety. Some, like the diplodocids, were extremely long and with tremendously long tails which they may have been able to crack like a
whipThe word whip describes two basic types of tools:A long stick-like device, usually slightly flexible, with a small bit of leather or cord, called a "popper", on the end. Depending on length and flexibility, this type is often called a riding whip, riding crop or "bat"...
to make
sonic boomThe term sonic boom is commonly used to refer to the shocks caused by the supersonic flight of an aircraft. Sonic booms generate enormous amounts of sound energy, sounding much like an explosion...
s.
SupersaurusSupersaurus is a genus of diplodocid sauropod dinosaur discovered in the Upper Jurassic Morrison Formation of Colorado in 1972...
, at 40 metres (130 ft), is probably the longest, but others, like the old record holder,
DiplodocusDiplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones located in...
, are still extremely long.
Amphicoelias fragillimus, of which only a drawing of a single
vertebraA vertebra is an individual bone in the flexible column that defines vertebrate animals, e.g. humans. The vertebral column encases and protects the spinal cord, which runs from the base of the cranium down the dorsal side of the animal until reaching the pelvis. From there, vertebra continue into...
survives, at 55 to 60 metres (180 to 200 ft) would have a spine even longer than the blue whale. The longest terrestrial animal alive today, the
reticulated pythonPython reticulatus, also known as the reticulated python or regal python, is a species of python found in Southeast Asia. Adults grow to over 28 feet in length and are the world's longest snakes and longest reptile, but are not the most heavily built...
, only reaches lengths of 10 metres (33 ft).
Others, like the brachiosaurids, were extremely tall, with high shoulders and extremely long necks.
SauroposeidonSauroposeidon is a genus of sauropod dinosaur known from four neck vertebrae that were found in the southwestern portion of the US state of Oklahoma...
is probably the tallest, reaching about 18 metres (60 ft) high, with the previous record for longest neck being held by
MamenchisaurusMamenchisaurus was a plant-eating four-legged dinosaur, known for its remarkably long neck. Most species lived 145 to 150 million years ago, in the Tithonian age of the late Jurassic Period....
. By comparison the
giraffeThe giraffe is an African even-toed ungulate mammal, the tallest of all land-living animal species, and the largest ruminant. It is covered in large, irregular patches of yellow to black fur separated by white, off-white, or dark yellowish brown background. The average mass for an adult male...
, the tallest of all living animals, is only 4.8 to 5.5 metres (16 to 18 ft) tall.
Some were almost incredibly massive:
ArgentinosaurusArgentinosaurus is a genus of sauropod dinosaur first discovered by Guillermo Heredia in Argentina. The generic name means "silver lizard", in reference to the country in which it was discovered...
is probably the heaviest at 80 to 100 metric tonnes (90 to 110
tonThe short ton is a unit of weight equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...
s), though
ParalititanParalititan was a giant titanosaurian sauropod dinosaur genus discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt. The fossil represents the first tetrapod reported from the Bahariya Formation since 1935. Its 1.69 meter long humerus is longer than that of any...
,
AndesaurusAndesaurus is a genus of basal titanosaurian sauropod dinosaur which existed during the middle of the Cretaceous Period in South America. Like most sauropods, it would have had a small head on the end of a long neck and an equally long tail...
,
AntarctosaurusAntarctosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, A. wichmannianus, was described by prolific German paleontologist Friedrich von Huene in 1929, who also described a second species in 1929...
, and
ArgyrosaurusArgyrosaurus Argyrosaurus Argyrosaurus ( ; meaning 'Silver lizard', because it was discovered in Argentina, which is sometimes known as 'Silver land' (Greek argyros meaning 'silver' and sauros meaning 'lizard') was a genus of herbivorous titanosaurid dinosaur that lived about 70 million years ago,...
are of comparable sizes. There is some very poor evidence of an even more massive titanosaurian,
BruhathkayosaurusBruhathkayosaurus might have been the largest dinosaur that ever lived. The accuracy of this claim, however, has been mired in controversy and debate...
, which might have weighed between 175 to 220 tonnes (190 to 240 tons). The largest land animal alive today, the Savannah
elephantElephants are large land mammals in two genera of the family Elephantidae: Elephas and Loxodonta. Three species of elephant are living today: the African Bush Elephant, the African Forest Elephant and the Asian Elephant...
, weighs no more than 10 tonnes (11 tons).
Among the smallest sauropods were the primitive
OhmdenosaurusOhmdenosaurus is the name given to a genus of dinosaur from the Early Jurassic. It was a very small vulcanodont sauropod which lived in Germany. Only a couple of fragmentary leg bones were found....
(4 m, or 13 ft long), the dwarf
titanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus...
MagyarosaurusMagyarosaurus was a small sauropod from late Cretaceous Period of what is now Romania and one of the smallest-known adult sauropods, measuring only 6 meters in length...
(5.3 m or 17 ft long), and the dwarf brachiosaurid
EuropasaurusEuropasaurus is a basal macronarian sauropod, a form of quadrapedal herbivorous dinosaur. It lived during the Upper Jurassic of northern Germany, and has been identified as an example of insular dwarfism resulting from the isolation of a sauropod population on an island within the Lower Saxony...
, which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of
insular dwarfismInsular dwarfism, a form of Phyletic dwarfism, is the process and condition of the reduction in size of large animals – almost always mammals – when their gene pool is limited to a very small environment, primarily islands...
of a herd of sauropods stranded on an island in what is now
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
. Also notable is the diplodocoid sauropod
BrachytrachelopanBrachytrachelopan is an unusual short-necked sauropod dinosaur from the latest Jurassic Period of Argentina. The holotype and only known specimen was collected from an erosional exposure of fluvial sandstone within the Cañadón Cálcero Formation on a hill approximately 25 km north-northeast...
, which was the shortest member of its group thanks to its unusually short neck. Unlike other sauropods, whose necks could grow to up to four times the length of their backs, the neck of
Brachytrachelopan was shorter than its backbone.
Limbs and feet
As massive quadrupeds, sauropods developed specialized
graviportal (weight-bearing) limbs. The hind feet were broad, and retained three claws in most species. Particularly unusual compared with other animals were the highly modified front feet (
manusThe manus is the zoological term for the distal portion of the fore limb of an animal. In tetrapods, it is the part of the pentadactyl limb that includes the metacarpals and digits . During evolution, it has taken many forms and served a variety of functions...
). The front feet of sauropods were very dissimilar from those of modern large quadrupeds such as
elephantElephants are large land mammals in two genera of the family Elephantidae: Elephas and Loxodonta. Three species of elephant are living today: the African Bush Elephant, the African Forest Elephant and the Asian Elephant...
s. Rather than splaying out to the sides to create a wide foot as in elephants, the manus bones of sauropods were arranged in fully vertical columns, with extremely reduced finger bones (though the most primitive sauropods, such as
VulcanodonVulcanodon was a relatively small, early sauropod dinosaur genus from the Early Jurassic. It was about 6.5 meters long. Vulcanodon ate plants and lived in southern Africa. The type species, V. karibaensis, was formally described by Michael A. Raath of the University of the Witwatersrand,...
and
BarapasaurusBarapasaurus meaning 'big-legged lizard', referring to the size of its leg bone is a genus of sauropod dinosaur from Early Jurassic rocks of India.-Description:Barapasaurus is of interest because it one of the earliest known sauropod, dating from the early...
, retained splayed and finger-bearing forefeet). The front feet were so modified in eusauropods that individual digits would not have been visible in life, with the whole manus modified into a hoof-like structure.
The arrangement of the forefoot bone (
metacarpalThe metacarpus is the intermediate part of the hand skeleton that is located between the phalanges distally and the carpus which forms the connection to the forearm. The metacarpus consists of metacarpal bones....
) columns in eusauropods was semi-circular, so sauropod forefoot prints are horseshoe-shaped. Unlike elephants, print evidence shows that sauropods lacked any fleshy padding to back the front feet, making them concave. The only claw visible in most sauropods was the distinctive thumb claw (associated with digit I). Almost all sauropods had such a claw, though what purpose it served is unknown. The claw was largest (as well as tall and laterally flattened) in diplodocids, and very small in brachiosaurids, some of which seem to have lost the claw entirely based on trackway evidence.
Titanosaurs also lost the thumb claw completely (with the exception of early forms such as
JanenschiaJanenschia was a large sauropod from Late Jurassic Africa , and therefore the earliest known titanosaur. Originally thought to be a species of the diplodocid Tornieria/Barosaurus , it was later found to be a distantly related titanosaur. So far, it is only known from Tanzania...
). Titanosaurs were most unusual among sauropods, as in addition to the external claw, they completely lost the digits of the front foot. Advanced titanosaurs had no digits or digit bones, and walked only on horseshoe-shaped "stumps" made up of the columnar metacarpal bones.
Print evidence from
PortugalPortugal , officially the Portuguese Republic , is a country located in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of mainland Europe and is bordered by the Atlantic Ocean to the west and south and by Spain to the north and east...
shows that in at least some sauropods (probably brachiosaurids), the bottom and sides of the forefoot column was likely covered in small, spiny scales, which left score marks in the prints. In titanoaurs, the ends of the metacarpal bones that contacted the ground were unusually broad and squared-off, and some specimens preserve the remains of soft tissue covering this area, suggesting that the front feet were rimmed with some kind of padding in these species.
Air sacs
Like other
saurischiaSaurischia is one of the two orders, or basic divisions, of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two orders, based on their hip structure...
n dinosaurs (such as
birdBirds are winged, bipedal, endothermic , vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the Bee Hummingbird to the ...
s and other theropods), sauropods had a system of air sacs evidenced by indentations and hollow cavities in most of their vertebrae. Such openings in the back, neck, and tail bones are referred to as
pneumaticity, and pneumatic, hollow bones are a characteristic feature of all sauropods.
The bird-like hollowing of sauropod bones was recognized early in the study of these animals, and in fact at least one sauropod specimen found in the 19th Century (
OrnithopsisOrnithopsis was a medium-sized Early Cretaceous sauropod dinosaur, described by Harry Seeley in 1870. The type is known from dorsal vertebrae from Europe. It has been considered a synonym of the wastebasket taxon Pelorosaurus, but recent research suggests that this is not as clear-cut as supposed...
) was originally misidentified as a flying
pterosaurPterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period...
because of this.
Armor
Some sauropods had
armorArmour in animals is external or superficial protection against attack by predators, formed as part of the body , usually through the hardening of body tissues, outgrowths or secretions. It has therefore mostly developed in 'prey' species...
. There were genera with
spinedIn biology, spine or spiny may refer to:*Spine , needle-like structures in plants*Spine , needle-like structures in animalsSpine may also refer to:*Vertebral column, spine in anatomy, the backbone...
backs, such as the
AgustiniaAgustinia is a genus of sauropod dinosaur from the Early Cretaceous Period of South America. Like all known sauropods, it was quadrupedal and herbivorous. Although some sauropods are known to have body armor, Agustinias armor was unique even among sauropods...
, and some has small
clubIn zoology, a club is a bony mass at the end of the tail of some dinosaurs and of some mammals, most notably the ankylosaurids and the glyptodonts...
s on their tails, like
ShunosaurusShunosaurus, meaning "Shu Lizard", is a genus of sauropod dinosaur from Middle Jurassic beds in Sichuan Province in China, 170 million years ago. The name derives from "Shu", an ancient name for Sichuan. It was collected from the Lower Shaximiao Formation in Dashanpu, Zigong...
. Several
titanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus...
s, such as
SaltasaurusSaltasaurus is a genus of sauropod dinosaur of the Late Cretaceous Period. Relatively small among sauropods, though still massive by human standards, it was characterized by a diplodocid-like head and was the first discovered with small bony plates embedded in its skin...
and
AmpelosaurusAmpelosaurus is a titanosaurian sauropod dinosaur hailing from the Late Cretaceous Period of what is now Europe. Like most sauropods, it would have had a long neck and tail but it also carried armor in the form of osteoderms on its back. This dinosaur would have stretched about 15 meters from...
, had small bony
osteodermOsteoderms are bony deposits forming scales, plates or other structures in the dermal layers of the skin. Osteoderms are found in many groups of extant and extinct reptiles, including lizards, various groups of dinosaurs , crocodilians, phytosaurs, aetosaurs, placodonts, and Nanchangosaurus...
s covering portions of their bodies.
Herding and parental care
Many lines of fossil evidence, from both bone beds and trackways, indicate that sauropods were gregarious animals that formed
herdA herd is a large group of animals and is a form of collective animal behavior. The term is usually applied to mammals, particularly ungulates. Other terms are used for similar phenomena in other types of animal...
s. However, the makeup of the herds varied between species. Some bone beds, for example a site from the Middle Jurassic of
ArgentinaArgentina, officially the Argentine Republic , is the second largest country in South America, constituted as a federation of 23 provinces and an autonomous city, Buenos Aires. It is the eighth largest country in the world by land area and the largest among Spanish-speaking nations, though Mexico,...
, appear to show herds made up of individuals of various age groups, mixing juveniles and adults. However, a number of other fossil sites and trackways indicate that many sauropod species travelled in herds segregated by age, with juveniles forming herds separate from adults. Such segregated herding strategies have been found in species such as
AlamosaurusAlamosaurus, , is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now North America. It was a large quadrupedal herbivore, up to in length, and up to 33 tons in weight...
,
BellusaurusBellusaurus was a small short-necked sauropod dinosaur from the Middle Jurassic which measured about 4.8 metres long. Its fossils were found in Wucaiwan Formation rocks in the northeastern Junggar Basin in China....
, and some diplodocids.
In a review of the evidence for various herd types, Myers and Fiorillo attempted to explain why sauropods appear to have often formed segregated herds. Studies of microscopic tooth wear show that juvenile sauropods had diets that differed from their adult counterparts. Differing tooth wear suggests that juveniles had different feeding strategies than adults, so herding together would not have been as productive as herding separately, where individual herd members could forage in a coordinated way. The vast size difference between juveniles and adults may also have played a part in the different feeding and herding strategies.
Since the segregation of juveniles and adults must have taken place soon after hatching, Myers and Fiorillo concluded that species with age-segregated herds could not have exhibited much parental care, if any. On the other hand, scientists who have studied age-mixed sauropod herds suggested that these species may have cared for their young for an extended period of time before the young reached adulthood.
Exactly how segregated versus age-mixed herding varied across different groups of sauropods is unknown. Further examples of gregarious behavior will need to be discovered from more sauropod species to begin detecting possible patterns of distribution.
Rearing stance
Since early in the history of their study, scientists such as
OsbornHenry Fairfield Osborn was an American geologist, paleontologist, and eugenicist, "a first-rate science administrator and a third-rate scientist."...
have speculated that sauropods could rear up on their hind legs, using the tail as the third 'leg' of a tripod. A skeletal mount depicting the
diplodocidDiplodocids, or members of the family Diplodocidae , are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the earth, including Diplodocus and Supersaurus, which may have reached lengths of up to 34 m , and the gigantic Amphicoelias, known from a single...
Barosaurus lentusBarosaurus Barosaurus Barosaurus ( ; meaning 'heavy lizard' (Greek barys/βαρυς meaning 'heavy' and saurus/σαυρος meaning 'lizard') was a giant, long-tailed, long-necked, plant-eating dinosaur closely related to the more familiar Diplodocus...
rearing up on its hind legs at the
American Museum of Natural HistoryThe American Museum of Natural History , located on the Upper West Side, Manhattan, New York, USA, is one of the largest and most celebrated museums in the world...
is one illustration of this hypothesis. In a 2005 paper, Rothschild and Molnar reasoned that if sauropods had adopted a bipedal posture at times, there would be evidence of stress fractures in the forelimb 'hands'. However, none were found after they examined a large number of sauropod skeletons.
Heinrich Mallison (in 2009) was the first to study the physical potential for various sauropods to rear into a tripodal stance. Mallison found that some characters previously linked to rearing adaptations were actually unrelated (such as the wide-set hip bones of
titanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus...
s) or would actually have hindered rearing. For example, titanosaurs had an unusually flexible backbone, which would have decreased stability in a tripodal posture and would have put more strain on the muscles. Likewise, it is unlikely that
brachiosauridsBrachiosauridae are a family of dinosaurs, whose members are known as brachiosaurids. They were herbivorous quadrupeds with longer forelegs than hind legs - the name derives from the Greek for arm lizard - and long necks...
could rear up onto the hind legs, given their center of gravity was much farther forward than other sauropods, which would cause such a stance to be unstable.
Diplodocids, on the other hand, appear to have been well adapted for rearing up into a tripodal stance. Diplodocids had a center of mass directly over the hips, giving them greater balance on two legs. Diplodocids also had the most mobile necks of sauropods, a well-muscled pelvic girdle, and tail vertebrae with a specialised shape that would allow the tail to bear weight at the point it contacted the ground. Mallison concluded that diplodocids were better adapted to rearing than
elephantElephants are large land mammals in two genera of the family Elephantidae: Elephas and Loxodonta. Three species of elephant are living today: the African Bush Elephant, the African Forest Elephant and the Asian Elephant...
s, which do so occasionally in the wild. He also argues that stress fractures in the wild do not occur from everyday behaviour, such as feeding-related activities (contra Rothschild and Molnar).
Head and neck posture
There is controversy over whether sauropods held their heads near vertically or horizontally. The claim that the long necks of sauropods were used for browsing high trees has been questioned on the basis of calculations of the energy needed to create the arterial blood pressure for the head if it was held upright. These calculations suggest this would have taken up rough half of its energy intake. Further, to supply blood to the head vertically held high would have required blood pressure of around 700 mmHg at the heart. This would have required that their hearts were 15 times the size of whales of similar size. This suggests it was more likely the long neck was usually held horizontally to enable them to feed on plants over a very wide area without needing to move their bodies—a potentially large saving in energy for 30 to 40 ton animals. In support of this, reconstructions of the necks of Diplodocus
and Apatosaurus show that they are basically straight with a gentle decline orientating their heads in a "neutral, undeflected posture" when close to ground.
However, research on living animals has suggested that sauropod heads were held in an upright S-shaped curve. Inference from bones about "neutral head postures" which suggest a horizontal position may be unreliable, according to this research. If applied to living animals it would imply they also held their heads in this position, even though they in fact do not.
Trackways and locomotion
Sauropod
trackwayA trackway is an ancient route of travel for people and/or animals. In biology, a trackway can be a set of impressions in the soft earth, usually a set of footprints, left by an animal. A fossil trackway is the fossilized imprint of a trackway. Trackways have been found all over the world...
s and other
fossil footprintsAn ichnite 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 of the animals that made them...
(known as "ichnites") are known from abundant evidence present on most continents. Ichnites have helped support other biological hypotheses about sauropods, including general fore and hind foot anatomy (see Limbs and feet above). Generally, prints from the forefeet are much smaller than the hind feet, and often crescent-shaped. Occasionally ichnites preserve traces of the claws, and help confirm which sauropod groups lost claws or even digits on their forefeet.
Generally, sauropod trackways are divided into three categories based on the distance between opposite limbs: narrow gauge, medium gauge, and wide gauge. The gauge of the trackway can help determine how wide-set the limbs of various sauropods were and how this may have impacted the way they walked. A 2004 study by Day and colleagues found that a general pattern could be found among groups of advanced sauropods, with each sauropod family being characterised by certain trackway gauges. They found that most sauropods other than
titanosaurTitanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus...
s had narrow-gauge limbs, with strong impressions of the large thumb claw on the forefeet. Medium gauge trackways with claw impressions on the forefeet probably belong to brachiosaurids and other primitive titanosauriformes, which were evolving wider-set limbs but retained their claws. Primitive true titanosaurs also retained their forefoot claw but had evolved fully wide gauge limbs. Wide gauge limbs were retained by advanced titanosaurs, trackways from which show a wide gauge and lack of any claws or digits on the forefeet.
Size evolution
Several scientists have attempted to address the question of why sauropods attained such huge sizes. Gigantic sizes were reached early in sauropod evolution, going back to the first true sauropods in the late
TriassicThe Triassic is a geologic period and system that extends from about 251 to 199 Ma . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
Period. According to
Kenneth CarpenterKenneth Carpenter is a Paleontologist at the Denver Museum of Natural History and author or co-author of a number of books on dinosaurs and Mesozoic life...
, whatever evolutionary pressure caused large size must have therefore been present from the early origins of the group.
Studies of
mammalMammals are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both males and females are characterized by sweat glands, hair, three middle ear bones used in hearing, and a neocortex region in the brain.Mammals are divided into three main...
ian herbivores that attained large size, such as
elephantElephants are large land mammals in two genera of the family Elephantidae: Elephas and Loxodonta. Three species of elephant are living today: the African Bush Elephant, the African Forest Elephant and the Asian Elephant...
s, have found that larger size in plant-eating animals leads to greater efficiency in digesting food. Since larger animals have longer digestive systems, food is kept in digestion for significantly longer periods of time, allowing large animals to survive on lower-quality food sources. This is especially true of animals with a large number of 'fermentation chambers' along the intestine which allow microbes to accumulate and ferment plant material, aiding digestion. Throughout their evolutionary history, sauropod dinosaurs were found primarily in semi-arid, seasonally dry environments, with a corresponding seasonal drop in the quality of food during the dry season. The environment of most gigantic Late Jurassic sauropods such as
AmphicoeliasAmphicoelias is a genus of herbivorous sauropod dinosaur that includes what may be the largest dinosaur ever discovered, A. fragillimus. Based on surviving descriptions of a single fossil bone, A...
was essentially a
savannaA savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close...
, similar to the arid environments in which modern giant herbivores are found, supporting the idea that poor-quality food in an arid environment promotes the evolution of giant herbivores. Carpenter argued that other benefits of large size, such as relative immunity from predators, lower energy expenditure, and longer life span, were probably secondary advantages, and that sauropods attained large size primarily to help process food more efficiently.
History of discovery
The first scrappy fossil remains now recognized as sauropods all came from
EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
and were originally interpreted in a variety of different ways. Their relationship to other dinosaurs was not recognized until well after their initial discovery.
The first sauropod fossil to be scientifically described was a single tooth known by the non-
LinnaeanLinnaean can refer to:*Carolus Linnaeus*Linnaean taxonomy*Linnaean enterprise*Linnean...
descriptor
Rutellum implicatum"Rutellum" is the pre-Linnaean name given to a genus of dinosaur from the Middle Jurassic. It was a sauropod, possibly a cetiosaurid, which lived in what is now England. The "type species", "R. implicatum", was described in 1699 by Edward Lhuyd, and is notable as the earliest scientifically...
. This fossil was described by Edward LhuydEdward Lhuyd was a Welsh naturalist, botanist, linguist, geographer and antiquary....
in 1699, but was not recognized as a giant prehistoric reptile at the time. Dinosaurs would not be recognized as a group until over a century later.
Richard OwenSir Richard Owen KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
published the first modern scientific description of sauropods in 1841, in his paper naming CetiosaurusCetiosaurus meaning 'whale lizard', from the Greek cetus/κητος meaning 'sea monster' and saurus/σαυρος meaning 'lizard', was a sauropod dinosaur from the Mid to Late Jurassic Period in what are now Europe and Africa. It is estimated to have been about long and to have weighed roughly...
and CardiodonCardiodon was a genus of sauropod dinosaur, based on a tooth from the late Bathonian-age Middle Jurassic Forest Marble Formation of Wiltshire, England...
. Cardiodon
was known only from a two unusual, heart-shaped teeth (from which it got its name), which could not be identified beyond the fact that they came from a previously unknown large reptileReptiles, or members of the class Reptilia, are air-breathing, generally "cold-blooded" amniotes that generally have skin covered in scales or scutes. They are tetrapods and lay amniote eggs, whose embryos are surrounded by the amnion membrane...
. Cetiosaurus
was known from slightly better, but still scrappy remains. Owen thought at the time that Cetiosaurus
was a giant marine reptile related to modern crocodileA crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all members of the order Crocodilia: i.e...
s, hence its name, which means "whale lizard." A year later, when Owen coined the name Dinosauria, he did not include Cetiosaurus
and Cardiodon
in that group.
In 1850, Gideon MantellGideon Algernon Mantell MRCS FRS was an English obstetrician, geologist and palaeontologist...
recognized the dinosaurian nature of several bones assigned to Cetiosaurus
by Owen. Mantell noticed that the leg bones contained a medullary cavityThe medullary cavity is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow is stored...
, a characteristic of land animals. He assigned these specimens to the new genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
PelorosaurusPelorosaurus was a huge plant-eating dinosaur. Pelorosaurus was one of the first sauropod dinosaurs ever discovered. Pelorosaurus lived during the Early Cretaceous period, about 138-112 million years ago. Fossils have been found in England and Portugal. It was about fifty feet long...
, and grouped it together with the dinosaurs. However, Mantell still did not recognize the relationship to Cetiosaurus
.
The next sauropod find to be described and misidentified as something other than a dinosaur were a set of hip vertebrae described by Harry SeeleyHarry Govier Seeley was a British paleontologist who determined that dinosaurs fell into two great groups, the Saurischians and the Ornithischians, based on the nature of their pelvic bones and joints. He published his results in 1888, from a lecture he had delivered the previous year...
in 1870. Seeley found that the vertebrae were very lightly constructed for their size and contained openings for air sacs (pneumatization
). Such air sacs were at the time known only in birdBirds are winged, bipedal, endothermic , vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the Bee Hummingbird to the ...
s and pterosaurPterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period...
s, and Seeley considered the vertebrae to come from a pterosaur. He named the new genus OrnithopsisOrnithopsis was a medium-sized Early Cretaceous sauropod dinosaur, described by Harry Seeley in 1870. The type is known from dorsal vertebrae from Europe. It has been considered a synonym of the wastebasket taxon Pelorosaurus, but recent research suggests that this is not as clear-cut as supposed...
, or "bird face" because of this.
When more complete specimens of Cetiosaurus
were described by Phillips in 1871, he finally recognized the animal as a dinosaur related to Pelorosaurus
. However, it was not until the description of new, nearly complete sauropod skeletons from the United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
(representing ApatosaurusApatosaurus , including the popular but obsolete synonym Brontosaurus, is a genus of sauropod dinosaur that lived about 150 million years ago, during the Jurassic Period . It was one of the largest land animals that ever existed, with an average length of 23 m and a mass of at least 23 metric tons...
and CamarasaurusCamarasaurus meaning 'chambered lizard', referring to the holes in its vertebrae was a genus of quadrupedal, herbivorous dinosaurs...
) later that year that a complete picture of sauropods emerged. An approximate reconstruction of a complete sauropod skeleton was produced by John A. Ryder, based on the remains of Camarasaurus
, though many features were still inaccurate or incomplete according to later finds and biomechanical studies. Also in 1877, Richard LydekkerRichard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.Lydekker was born in London, and educated at Trinity College, Cambridge, where he took a first-class in the Natural Science tripos...
named another relative of Cetiosaurus
, TitanosaurusTitanosaurus is a genus of sauropod dinosaur, first described by Lydekker in 1877. It is known from the Maastrichtian Lameta Formation of India...
, based on an isolated vertebra.
In 1878, the most complete sauropod yet was found and described by Othniel Charles MarshOthniel Charles Marsh was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West.-Early life:...
, who named it DiplodocusDiplodocus is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones located in...
. With this find, Marsh also created a new group to contain Diplodocus
, Cetiosaurus
, and their increasing roster of relatives to differentiate them from the other major groups of dinosaurs. Marsh named this group Sauropoda, or "lizard feet."
Classification
Classification of the sauropods has largely stabilised in recent years, though there are still some uncertainties, such as the position of EuhelopusEuhelopus is a genus of sauropod dinosaur that lived during the Early Cretaceous, sometime between 130 and 112 million years ago . It lived in what is now Shandong Province in China. A large herbivore, it weighed approximately 15-20 tons and attained an adult length of 15m...
, HaplocanthosaurusHaplocanthosaurus is a genus of sauropod dinosaur. Two species, H. delfsi and H. priscus, are known from incomplete fossil skeletons. It lived during the late Jurassic period , 144 to 156 million years ago. The type species is H. priscus, and the referred species H...
, JobariaJobaria was a sauropod dinosaur discovered in the Sahara Desert in 1997, and is one of the most completely known Cretaceous sauropods. It was named after "Jobar", a creature of local legends, and is thought to have been about 18 metres long...
and
NemegtosauridaeNemegtosauridae is a family of probably titanosaurian sauropod dinosaurs based originally on two late Cretaceous Mongolian species known only from their diplodocid-like skulls: Nemegtosaurus and Quaesitosaurus. Authorities disagree as to the relationship of these two genera with other sauropods,...
. The following are two alternative recent classifications (showing supra-generic
cladeA clade is a term used in modern alpha taxonomy, the scientific classification of living and fossil organisms, to describe a monophyletic group, defined as a group consisting of a single common ancestor and all its descendants.[The term "monophyletic group" is used in this article...]
s only in the second example). These are by no means an exhaustive list of recent sauropod classification schemes. In some cases, families like Vulcanodontidae, Cetiosauridae and Omeisauridae are not included because they are considered paraphyletic, or even (in the case of Camarasauridae) polyphyletic.
Taxonomy
This taxonomy follows Wilson & Sereno 1998, Yates 2003, Galton 2001,
http://dml.cmnh.org/2003Jul/msg00103.html and Wilson 2002, with ranks after Benton, 2004.
- Infraorder Sauropoda
- Ammosaurus
Ammosaurus is a genus of sauropodomorph dinosaur from the Early and Middle Jurassic Period of North America. At 4 meters in length, it was small compared to some other members of its suborder, which included the largest animals ever to walk the Earth...
- Anchisaurus
Anchisaurus is a genus of sauropod, and was an early herbivorous dinosaur. Until recently it was classed as a member of the more primitive prosauropod family...
- ?Isanosaurus
Isanosaurus was one of the first true sauropod dinosaurs, with all four legs always on the ground. It lived 210 million years ago in Southeast Asia. The type species was Isanosaurus attavipachi...
- Kotasaurus
Kotasaurus is the name given to a genus of dinosaur from the Early Jurassic period, about 208 million to 188 million years ago. It was an early sauropod, sharing some similarities with prosauropods...
- Lessemsaurus
Lessemsaurus is an extinct genus of sauropodomorph dinosaur named for the writer of popular science books Don Lessem. The type species, L. sauropoides, was formally described by Jose Bonaparte in 1999...
- Family Blikanasauridae
Blikanasaurus was a genus of sauropodomorph dinosaur found in Lower Elliot Formation rocks from the Late Triassic in what is now South Africa's Cape Province. Known from a left lower limb only, it has been variously classified as a prosauropod or basal sauropod...
- Family Melanorosauridae
The Melanorosauridae were a family of sauropodomorph dinosaurs which lived during the Late Triassic and Early Jurassic. The name Melanorosauridae was first coined by Friedrich von Huene in 1929. Huene assigned several families of dinosaurs to the infraorder Prosauropoda: the Anchisauridae, the...
- Family Vulcanodontidae
The Early Jurassic sauropod dinosaurs Zizhongosaurus, Barapasaurus, Tazoudasaurus, and Vulcanodon may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by...
- Family Cetiosauridae
- Family Omeisauridae
Omeisauridae is an extinct family of sauropods.-References:* The Sauropods: Evolution and Paleobiology by Kristina Curry Rogers and Jeffrey Wilson * Vertebrate Palaeontology by Michael J. Benton...
- ?Family Tendaguridae
Tendaguria is a genus of sauropod dinosaur from the Late Jurassic of Tanzania.It was a large sauropod from the Tendaguru fossil locality in Tanzania; based on two anterior dorsal vertebrae from Nambango, 15 kilometers southeast of...
- Clade Turiasauria
Turiasauria is an unranked clade of sauropod dinosaurs, named for the genus Turiasaurus, a gigantic eusauropod from southwestern Europe. The clade also includes two other known members, Galveosaurus and Losillasaurus. All three taxa thus far referred to Turiasauria have come from the Villar del...
- Division Neosauropoda
Neosauropoda is a division-level clade of sauropods within Dinosauria, and consists of the group leading to Diplodocoidea and Macronaria. Haplocanthosaurus was a typical basal neosauropod from around 150 million years ago, in the Late Jurassic...
- Haplocanthosaurus
Haplocanthosaurus is a genus of sauropod dinosaur. Two species, H. delfsi and H. priscus, are known from incomplete fossil skeletons. It lived during the late Jurassic period , 144 to 156 million years ago. The type species is H. priscus, and the referred species H...
- ?Jobaria
Jobaria was a sauropod dinosaur discovered in the Sahara Desert in 1997, and is one of the most completely known Cretaceous sauropods. It was named after "Jobar", a creature of local legends, and is thought to have been about 18 metres long...
- Superfamily Diplodocoidea
Diplodocoidea was a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like Supersaurus, Diplodocus, Apatosaurus, and Amphicoelias...
- Family Rebbachisauridae
Rebbachisauridae is a family of sauropod dinosaurs known from fragmentary fossil remains from the Cretaceous of South America, Africa, and Europe.-Taxonomy:...
- Family Dicraeosauridae
Dicraeosauridae is a family of sauropod dinosaurs known from the Late Jurassic and Early Cretaceous of Africa and South America. Currently only three genera are recognised; the Jurassic South American genus Brachytrachelopan, the Jurassic African Dicraeosaurus and the South American Early...
- Family Diplodocidae
- Subdivision Macronaria
Macronaria is a clade of sauropod dinosaurs from the Middle Jurassic to Late Cretaceous Periods of what are now North America, South America, Europe, Asia and Africa. The name means 'large nostrils', in reference to the large nasal openings high on the head that probably supported fleshy...
- Family Brachiosauridae
Brachiosauridae are a family of dinosaurs, whose members are known as brachiosaurids. They were herbivorous quadrupeds with longer forelegs than hind legs - the name derives from the Greek for arm lizard - and long necks...
- Family Camarasauridae
- Family Euhelopodidae
Euhelopus is a genus of sauropod dinosaur that lived during the Early Cretaceous, sometime between 130 and 112 million years ago . It lived in what is now Shandong Province in China. A large herbivore, it weighed approximately 15-20 tons and attained an adult length of 15m...
- Superfamily Titanosauroidea
Phylogeny
Cladogram simplified after Wilson, 2002.
{{clade| style=font-size:100%;line-height:80%
|label1=
Sauropoda
|1={{clade
|1=
VulcanodonVulcanodon was a relatively small, early sauropod dinosaur genus from the Early Jurassic. It was about 6.5 meters long. Vulcanodon ate plants and lived in southern Africa. The type species, V. karibaensis, was formally described by Michael A. Raath of the University of the Witwatersrand,...
|label2=Eusauropoda
|2={{clade
|1=ShunosaurusShunosaurus, meaning "Shu Lizard", is a genus of sauropod dinosaur from Middle Jurassic beds in Sichuan Province in China, 170 million years ago. The name derives from "Shu", an ancient name for Sichuan. It was collected from the Lower Shaximiao Formation in Dashanpu, Zigong...
|label2=unnamed
|2={{clade
|1=BarapasaurusBarapasaurus meaning 'big-legged lizard', referring to the size of its leg bone is a genus of sauropod dinosaur from Early Jurassic rocks of India.-Description:Barapasaurus is of interest because it one of the earliest known sauropod, dating from the early...
|label2=unnamed
|2={{clade
|1=PatagosaurusPatagosaurus was a large herbivorous dinosaur from the long-necked group Sauropoda. It reached a length of 18 meters. Similar to other primitive eusauropods, it was rather heavily built and similar to Cetiosaurus in general appearance. It is known from a dozen individuals, though some referred...
|label2=unnamed
|2={{clade
|1=OmeisaurusOmeisaurus is a genus of sauropod dinosaur from the Late Jurassic Period of what is now China. Its name comes from Mount Emei, where it was discovered....
|2=MamenchisaurusMamenchisaurus was a plant-eating four-legged dinosaur, known for its remarkably long neck. Most species lived 145 to 150 million years ago, in the Tithonian age of the late Jurassic Period....
}}
|label3=unnamed
|3={{clade
|1=JobariaJobaria was a sauropod dinosaur discovered in the Sahara Desert in 1997, and is one of the most completely known Cretaceous sauropods. It was named after "Jobar", a creature of local legends, and is thought to have been about 18 metres long...
|label2=NeosauropodaNeosauropoda is a division-level clade of sauropods within Dinosauria, and consists of the group leading to Diplodocoidea and Macronaria. Haplocanthosaurus was a typical basal neosauropod from around 150 million years ago, in the Late Jurassic...
|2={{clade
|1=HaplocanthosaurusHaplocanthosaurus is a genus of sauropod dinosaur. Two species, H. delfsi and H. priscus, are known from incomplete fossil skeletons. It lived during the late Jurassic period , 144 to 156 million years ago. The type species is H. priscus, and the referred species H...
|2=DiplodocoideaDiplodocoidea was a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like Supersaurus, Diplodocus, Apatosaurus, and Amphicoelias...
|label3=MacronariaMacronaria is a clade of sauropod dinosaurs from the Middle Jurassic to Late Cretaceous Periods of what are now North America, South America, Europe, Asia and Africa. The name means 'large nostrils', in reference to the large nasal openings high on the head that probably supported fleshy...
|3={{clade
|1=CamarasaurusCamarasaurus meaning 'chambered lizard', referring to the holes in its vertebrae was a genus of quadrupedal, herbivorous dinosaurs...
|label2=Titanosauriformes
|2={{clade
|1=BrachiosaurusBrachiosaurus , meaning "arm lizard", from the Greek brachion/βραχιων meaning "arm" and sauros/σαυρος meaning "lizard", was a genus of sauropod dinosaur that lived during the Late Jurassic Period and possibly the Early Cretaceous Period. It was named thus because its forelimbs were longer than its...
|label2=Somphospondyli
|2={{clade
|1=EuhelopusEuhelopus is a genus of sauropod dinosaur that lived during the Early Cretaceous, sometime between 130 and 112 million years ago . It lived in what is now Shandong Province in China. A large herbivore, it weighed approximately 15-20 tons and attained an adult length of 15m...
|2=Titanosauria
}}
}}
}}
}}
}}
}}
}}
}}
}}
}}