127-539: Titanosaurs (or titanosaurians; members of the group Titanosauria ) were a diverse group of sauropod dinosaurs , including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous . This group includes some of the largest land animals known to have ever existed, such as Patagotitan , estimated at 37 m (121 ft) long with
254-495: A basal titanosauriform. The tracks are wide-gauge, and the grouping as close to Sauropodichnus is also supported by the manus-to-pes distance, the morphology of the manus being kidney bean-shaped, and the morphology of the pes being subtriangular. It cannot be identified whether the footprints of the herd were caused by juveniles or adults, because of the lack of previous trackway individual age identification. Generally, sauropod trackways are divided into three categories based on
381-420: 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
508-526: A characteristic feature of all sauropods. These air spaces reduced the overall weight of the massive necks that the sauropods had, and the air-sac system in general, allowing for a single-direction airflow through stiff lungs, made it possible for the sauropods to get enough oxygen. This adaptation would have advantaged sauropods particularly in the relatively low oxygen conditions of the Jurassic and Early Cretaceous. The bird-like hollowing of sauropod bones
635-426: A clade called Lithostrotia , which some researchers consider equivalent to the deprecated Titanosauridae. Lithostrotians include titanosaurs such as Alamosaurus , Isisaurus , Malawisaurus , Rapetosaurus , and Saltasaurus . Titanosaurus indicus was first named by British paleontologist Richard Lydekker in 1877 , as a new taxon of dinosaur based on two caudals and a femur collected on different occasions at
762-470: A few bones. Titanosaur skulls are especially rare. Though fragmentary cranial remains are known for several titanosaur genera, nearly complete skulls have been described for only four: Nemegtosaurus , Rapetosaurus , Sarmientosaurus , and Tapuiasaurus . As is the case in most other sauropod groups, there are few titanosaur specimens with complete necks preserving all of the cervical vertebrae in sequence. Only three complete titanosaur necks are known:
889-402: A great number of adaptations in their skeletal structure. Some sauropods had as many as 19 cervical vertebrae , whereas almost all mammals are limited to only seven. Additionally, each vertebra was extremely long and had a number of empty spaces in them which would have been filled only with air. An air-sac system connected to the spaces not only lightened the long necks, but effectively increased
1016-502: A large diagnosis of the family: "dorsals with irregularly shaped pleurocoels and spines directed strongly backward; transverse processes directed dorsally as well as laterally, very robust in shoulder region; a second dorsosacral, its rib fused to ilium; caudals strongly procoelous with a prominent ball on distal end of centrum throughout tail; caudal arches on front half of centrum; sternal plates large; preacetabular process of ilium swept outward to become almost horizontal", but stressed that
1143-422: A large energy saving for such a large animal. Reconstructions of the necks of Diplodocus and Apatosaurus have therefore often portrayed them in near-horizontal, so-called "neutral, undeflected posture". However, research on living animals demonstrates that almost all extant tetrapods hold the base of their necks sharply flexed when alert, showing that any inference from bones about habitual "neutral postures"
1270-466: A less robust pubis; Upchurch considered the clade sister taxon to Diplodocoidea , because of their shared dental anatomy, although he noted that peg-like teeth might have been independently evolved. This was followed up by Upchurch's 1998 study on sauropod phylogenetics, which additionally recovered Phuwiangosaurus and Andesaurus within Titanosauroidea and resolved Opisthocoelicaudia as
1397-404: A low position which, together with their strange orientation, indicates some special, as yet not fully understood, way of cropping vegetation. The neck vertebrae are long and elongated. Their internal structure is camellated, i.e. with many small air spaces inside. The middle neck vertebrae have oval, narrow and deep pleurocoels in their sides, pneumatic excavations that nearly touch each other on
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#17327974715671524-421: A more primitive form of dorsal vertebrae. Sauropod hands already are highly derived from other dinosaurs, being reduced into columnar metacarpals and blocky phalanges with fewer claws. However, titanosaurs evolved the manus even further, completely losing the phalanges and heavily modifying the metacarpals. Argyrosaurus is the only titanosaur known to possess carpals . Other taxa like Epachthosaurus show
1651-516: A non-insular context in Upper Creaceous Brazil, and is an example of nanism resultant from other ecological pressures. The heads of titanosaurs are poorly known. However, several different cranial morphologies are apparent. In some species, such as Sarmientosaurus , the head resembled that of brachiosaurids . In others, such as Rapetosaurus and Nemegtosaurus , the head resembled that of diplodocids . In some titanosaurs,
1778-513: A part in the different feeding and herding strategies. Since the segregation of juveniles and adults must have taken place soon after hatching, and combined with the fact that sauropod hatchlings were most likely precocial , Myers and Fiorillo concluded that species with age-segregated herds would not have exhibited much parental care. 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
1905-482: A phylogenetic study on Titanosauriformes , including relationships within Titanosauria. They provided a definition for the clade of "including the most recent common ancestor of Andesaurus delgadoi and Titanosauridae and all of its descendants". Titanosauria resolved including the same two subclades as Bonaparte & Coria (1993), where Andesauridae was monotypic, only including the name genus, and Titanosauridae
2032-488: A poorly-known group, and the relationships between titanosaur species are still not well-understood. Due to the near-global distribution of titanosaurs during the Cretaceous, titanosaur fossils have been found on every continent, including Antarctica. However, titanosaurs have the least complete fossil record of any major sauropodomorph group. No complete titanosaur skeletons are known, and many species are only known from
2159-490: A population of sauropods isolated on an island of the late Jurassic in what is now the Langenberg area of northern Germany . The diplodocoid sauropod Brachytrachelopan was the shortest member of its group because of 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. Fossils from perhaps
2286-495: A position much above the shoulders for exploring the area or reaching higher. Another proposed function of the sauropods' long necks was essentially a radiator to deal with the extreme amount of heat produced from their large body mass. Considering that the metabolism would have been doing an immense amount of work, it would certainly have generated a large amount of heat as well, and elimination of this excess heat would have been essential for survival. It has also been proposed that
2413-498: A reduction of phalanges to one or two bones. Opisthoeoclicaudia shows even more reduction of the hand than other titanosaurs, with both carpals and phalanges completely absent. However, Diamantinasaurus , while lacking carpals, preserves a manual formula of 2–1–1–1–1 , including a thumb claw and phalanges on all other digits. This, coupled with the preservation of a single phalanx on digit IV of Epachthosaurus and potentially Opisthocoelicaudia (further study
2540-461: A result, the fossilized trackways of titanosaurs are distinctly broader than other sauropods. Their forelimbs were also stocky, and often longer than their hind limbs. Unlike other sauropods, some titanosaurs had no digits, walking only on horseshoe-shaped "stumps" made up of the columnar metacarpal bones. Their vertebrae (back bones) were solid (not hollowed-out), which may be a reversal to more basal saurischian characteristics. Their spinal column
2667-483: 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, 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
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#17327974715672794-530: A short classification of Sauropoda, where he placed the Titanosaurinae (a reranking of Lydekker's Titanosauridae) in Morosauridae , and included the genera Titanosaurus , Hypselosaurus and Macrurosaurus because they all had strongly procoelous caudals. German paleontologist Friedrich von Huene provided a significant revision of Titanosauridae the following year in 1929 , where he reviewed
2921-582: A significant role in defense. However, they may have played an important role in nutrient storage for titanosaurs living in highly seasonal climates and for female titanosaurs laying eggs. Osteoderms were present on both large and small species, so they were not solely used by smaller species as protection against predators. New evidence published in 2021 suggests there were indeed some defensive purposes in titanosaur osteoderms; simulated bite marks from both baurusuchid crocodylomorphs and abelisaurids on titanosaurid osteoderms suggest they could be useful for protecting
3048-404: 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
3175-455: A stilt-walker principle (suggested by amateur scientist Jim Schmidt) in which the long legs of adult sauropods allowed them to easily cover great distances without changing their overall mechanics. Along with other saurischian dinosaurs (such as theropods , including birds), sauropods had a system of air sacs , evidenced by indentations and hollow cavities in most of their vertebrae that had been invaded by them. Pneumatic, hollow bones are
3302-455: A tongue-shaped process overlapping the rear of the quadrate. In the braincase there are three separate exits for the nervus trigeminus . An inner vein channel connecting the infundibulum with the brains stem, is lacking. The premaxillary teeth are positioned vertically, the maxillary teeth are inclining to the front and the dentary teeth are inclining to the rear. The middle neck vertebrae have strut-like, instead of plate-shaped, ridges between
3429-431: A weight of 69 tonnes (76 tons), and the comparably-sized Argentinosaurus and Puertasaurus from the same region . The group's name alludes to the mythological Titans of ancient Greek mythology , via the type genus (now considered a nomen dubium ) Titanosaurus . Together with the brachiosaurids and relatives, titanosaurs make up the larger sauropod clade Titanosauriformes . Titanosaurs have long been
3556-414: A wide gauge and lack of any claws or digits on the forefeet. Occasionally, only trackways from the forefeet are found. Falkingham et al. used computer modelling to show that this could be due to the properties of the substrate. These need to be just right to preserve tracks. Differences in hind limb and fore limb surface area, and therefore contact pressure with the substrate, may sometimes lead to only
3683-740: Is Sarmientosaurus musacchioi . In 1997, paleontologist Rubén D.F. Martínez, at the Estancia Laguna Palacios of the Goicoechea family in Chubut province , discovered a sauropod skull. This proved to be connected to the first few cervical vertebrae. In 2016, the type species Sarmientosaurus musacchioi was named and described by Rubén Darío Francisco Martínez , Matthew Carl Lamanna , Fernando Emilio Novas , Ryan C. Ridgely, Gabriel Andrés Casal , Javier E. Martínez, Javier R. Vita and Lawrence M. Witmer . The generic name refers to
3810-551: Is a clade of saurischian ('lizard-hipped') dinosaurs . Sauropods 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 Apatosaurus , Argentinosaurus , Alamosaurus , Brachiosaurus , Camarasaurus , Diplodocus , and Mamenchisaurus . The oldest known unequivocal sauropod dinosaurs are known from
3937-429: Is a notable size increase among sauropodomorphs, although scanty remains of this period make interpretation conjectural. There is one definite example of a small derived sauropodomorph: Anchisaurus , under 50 kg (110 lb), even though it is closer to the sauropods than Plateosaurus and Riojasaurus , which were upwards of 1 t (0.98 long tons; 1.1 short tons) in weight. Evolving from sauropodomorphs,
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4064-453: Is deeply unreliable. Meanwhile, computer modeling of ostrich necks has raised doubts over the flexibility needed for stationary grazing. Sauropod trackways and other fossil footprints (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
4191-898: Is evidence that they preferred wet and coastal habitats. Sauropod footprints are commonly found following coastlines or crossing floodplains, and sauropod fossils are often found in wet environments or intermingled with fossils of marine organisms. A good example of this would be the massive Jurassic sauropod trackways found in lagoon deposits on Scotland 's Isle of Skye . Studies published in 2021 suggest sauropods could not inhabit polar regions. This study suggests they were largely confined to tropical areas and had metabolisms that were very different to those of other dinosaurs, perhaps intermediate between mammals and reptiles. New studies published by Taia Wyenberg-henzler in 2022 suggest that sauropods in North America declined due to undetermined reasons in regards to their niches and distribution during
4318-411: Is large, equalling 40% of the length of the skull. The ascending branch of the maxilla has a complex connection with a top process of the lacrimal bone , being wedged between its outer side and inner side. The inner edge of the rear part of the ascending branch of the maxilla touches the rim of the bony nostril with a low but distinct ridge. The ascending branch of the quadratojugal has at its lower rear
4445-492: Is necessary), show that preservation biases may be responsible for the lack of hand phalanges in these taxa. This suggests that Alamosaurus , Neuquensaurus , Saltasaurus and Rapetosaurus - all known from imperfect or disarticulated remains previously associated with a lack of phalanges - may have had phalanges but lost them after death. Titanosaurs have a poor fossil record of their pedes (feet), only being complete in five definitive titanosaurs. Among these, Notocolossus
4572-494: Is now known to be the result of convergent evolution. Titanosaurs are now known to be most closely related to euhelopodids and brachiosaurids ; together they form a clade named Titanosauriformes. For much of the 20th century, most known species of titanosaurs were classified in the family Titanosauridae, which is no longer in widespread use. Titanosauria was first proposed in 1993 as a taxon to encompass titanosaurids and their close relatives. It has been phylogenetically defined as
4699-573: Is shown in the fossil record. Moreover, it must be determined as to whether sauropod declines in North America was the result of a change in preferred flora that sauropods ate, climate, or other factors. It is also suggested in this same study that iguanodontians and hadrosauroids took advantage of recently vacated niches left by a decline in sauropod diversity during the late Jurassic and the Cretaceous in North America. Many lines of fossil evidence, from both bone beds and trackways, indicate that sauropods were gregarious animals that formed herds . However,
4826-624: Is the largest, and also has the most specialized pes: like all titanosaurs, its pes is composed of short, thick metatarsals of approximately the same lengths; however, metatarsals I and V are notably more robust than in other taxa. From skin impressions found with fossils , it has been determined that the skin of many titanosaurs was armored with a small mosaic of small, bead-like scales surrounding larger scales. While most titanosaurs were very large animals, many were fairly average in size compared to other giant dinosaurs. Some island-dwelling dwarf titanosaurs, such as Magyarosaurus , were probably
4953-421: 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 may have lost the thumb claw completely (with the exception of early forms, such as Janenschia ). Titanosaurs were most unusual among sauropods, as, across their history as a clade, they lost not just
5080-594: The Musculus rectus capitis anterior ventralis , the Musculus longus colli ventralis or the Musculi intertransversarii . The internal structure of the tendon, with much reworked bone tissue, indicated a swift ossification at a young age. Martínez and colleagues placed Sarmientosaurus in a basal position within the clade Lithostrotia , above Malawisaurus in the evolutionary tree. However, in 2021, Stephen Poropat and colleagues instead identified it as part of
5207-489: The African elephant , can only reach lengths of 7.3 metres (24 ft). Others, like the brachiosaurids , were extremely tall, with high shoulders and extremely long necks. The tallest sauropod was the giant Barosaurus specimen at 22 m (72 ft) tall. By comparison, the giraffe , the tallest of all living land animals, is only 4.8 to 5.6 metres (15.74 to 18.3 ft) tall. The best evidence indicates that
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5334-466: The Cenomanian to Turonian ages. It consists of an almost complete skull with lower jaws, articulated with the first seven vertebrae of the front neck. Several neck parts, among them the entire atlas and fourth neck vertebra, were too eroded to be salvaged. The specimen represents an elderly individual. It is one of the few titanosaurs for which skull material has been found. Uniquely, at the side of
5461-742: The Early Jurassic . Isanosaurus and Antetonitrus were originally described as Triassic sauropods, but their age, and in the case of Antetonitrus also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation ( Greenland ) might, however, indicate the occurrence of the group in the Late Triassic . By the Late Jurassic (150 million years ago), sauropods had become widespread (especially
5588-473: The blue whale in size. The weight of Amphicoelias fragillimus was estimated at 122.4 metric tons with lengths of up to nearly 60 meters but 2015 research argued that these estimates were based on a diplodocid rather than the more modern rebbachisaurid, suggesting a much shorter length of 35–40 meters with mass between 80–120 tons. Additional finds indicate a number of species likely reached or exceeded weights of 40 tons. The largest land animal alive today,
5715-430: The bush elephant , weighs no more than 10.4 metric tons (11.5 short tons). Among the smallest sauropods were the primitive Ohmdenosaurus (4 m, or 13 ft long), the dwarf titanosaur Magyarosaurus (6 m or 20 ft long), and the dwarf brachiosaurid Europasaurus , which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of insular dwarfism occurring in
5842-555: The diplodocids and brachiosaurids ). By the Late Cretaceous , one group of sauropods, the titanosaurs , had replaced all others and 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
5969-497: The rorquals , such as the blue whale . But, unlike whales, sauropods were primarily terrestrial animals . Their body structure did not vary as much as other dinosaurs, perhaps due to size constraints, but they displayed ample variety. Some, like the diplodocids , possessed tremendously long tails, which they may have been able to crack like a whip as a signal or to deter or injure predators, or to make sonic booms . Supersaurus , at 33 to 34 metres (108 to 112 ft) long,
6096-458: The 1970s, the effects of sauropod air sacs on their supposed aquatic lifestyle began to be explored. Paleontologists such as Coombs and Bakker used this, as well as evidence from sedimentology and biomechanics , to show that sauropods were primarily terrestrial animals. In 2004, D.M. Henderson noted that, due to their extensive system of air sacs, sauropods would have been buoyant and would not have been able to submerge their torsos completely below
6223-432: The 19th and early 20th centuries concluded that sauropods were too large to have supported their weight on land, and therefore that they must have been mainly aquatic . Most life restorations of sauropods in art through the first three quarters of the 20th century depicted them fully or partially immersed in water. This early notion was cast in doubt beginning in the 1950s, when a study by Kermack (1951) demonstrated that, if
6350-466: The Middle Triassic of Argentina, weighed approximately 1 kg (2.2 lb) or less. These evolved into saurischia, which saw a rapid increase of bauplan size, although more primitive members like Eoraptor , Panphagia , Pantydraco , Saturnalia and Guaibasaurus still retained a moderate size, possibly under 10 kg (22 lb). Even with these small, primitive forms, there
6477-640: The Rebbachisauridae, titanosaurs lost the hyposphene-hypantrum articulations , a set of surfaces between vertebrae that prevent additional rotation of the bones. Andesaurus , one of the most basal titanosaurs, shows a normal hyposphene. The same area is reduced in Argentinosaurus to only two ridges, and is fully absent in taxa like Opisthocoelicaudia and Saltasaurus . Both Argentinosaurus and Epachthosaurus bear similar intermediate "hyposphenal ridges", which suggests they represent
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#17327974715676604-803: The absence of a hyposphene-hypantrum, no femoral fourth trochanter, and osteoderms. A small clade of Alamosaurus , Lirainosaurus and the "Peirópolis titanosaur" ( Trigonosaurus ) was resolved, and diagnosed by only a rotation of the tibia so the proximal end is perpendicular to the distal end. More derived clades, while resolved, were only weakly supported, or characterized by reversions of diagnostic traits of larger groups (below and left). Powell (2003) Opisthocoelicaudia Epachthosaurus Alamosaurus Lirainosaurus Trigonosaurus (="Peirópolis titanosaur") Sauropoda Sauropoda ( / s ɔː ˈ r ɒ p ə d ə / ), whose members are known as sauropods ( / ˈ s ɔːr ə p ɒ d z / ; from sauro- + -pod , ' lizard -footed'),
6731-440: The addition of more phylogenetics and the recognition of Titanosauria as a clade name. Using the datamatrix of Sanz et al. (1999) and modifying it to include additional taxa and some character changes, Powell found that titanosaurs formed mostly a single gradual radiation beginning with Epachthosaurus as the most basal titanosaur, and Ampelosaurus and Isisaurus as the most derived. Titanosauroidea (following Upchurch 1995),
6858-550: The airflow through the trachea, helping the creatures to breathe in enough air. By evolving vertebrae consisting of 60% air, the sauropods were able to minimize the amount of dense, heavy bone without sacrificing the ability to take sufficiently large breaths to fuel the entire body with oxygen. According to Kent Stevens, computer-modeled reconstructions of the skeletons made from the vertebrae indicate that sauropod necks were capable of sweeping out large feeding areas without needing to move their bodies, but were unable to be retracted to
6985-418: The animal were submerged in several metres of water, the pressure would be enough to fatally collapse the lungs and airway. However, this and other early studies of sauropod ecology were flawed in that they ignored a substantial body of evidence that the bodies of sauropods were heavily permeated with air sacs . In 1878, paleontologist E.D. Cope had even referred to these structures as "floats". Beginning in
7112-423: The animal's back, an arrangement similar to the plates of stegosaurs . Several other arrangements have been proposed, such as a single row along the midline, and it is possible that different species had different arrangements. The osteoderms were certainly far more sparse than those of ankylosaurs , and did not completely cover the back in scutes. Because of their sparse arrangement, it was unlikely that they served
7239-583: The animals in addition to functioning in mineral storage. Shunosaurus Mamenchisauridae Turiasauria Rebbachisauridae Dicraeosauridae Diplodocidae Camarasaurus Brachiosauridae Euhelopodidae Titanosauria Titanosaurs are classified as sauropod dinosaurs . This highly diverse group forms the dominant clade of Cretaceous sauropods. Within Sauropoda, titanosaurs were once classified as close relatives of Diplodocidae due to their shared characteristic of narrow teeth, but this
7366-483: The articulations were united within the new family Andesauridae , and the two families were grouped together within the new clade Titanosauria. The titanosaurs were diagnosed by possessing small pleurocoels centered within an anteroposteriorly elongate depression and the presence of two well defined depressions on the posterior face of the neural arch. The entire group was compared favourably with cetiosaurids like Patagosaurus and Volkheimeria . Overlooking
7493-408: The clade composed of the most recent common ancestor of Saltasaurus and Andesaurus and all of its descendants. The relationships of species within Titanosauria remain largely unresolved, and it is considered one of the most poorly-understood areas of dinosaur classification. One of the few areas of agreement is that the majority of titanosaurs except Andesaurus and some other basal species form
7620-401: The dentary thirteen. The premaxillary teeth are positioned vertically, the maxillary teeth incline to the front while the teeth of the lower jaw incline to behind, a unique configuration. The build of the teeth is in-between the more spatulate form of basal sauropods and the pencil shape of derived species. The teeth are moderately elongated. They each have sharply-angled wear facets in a high and
7747-449: The dinosaurs of Cretaceous Argentina , and named multiple new genera. Huene included multiple species of Titanosaurus from India, England , France , Romania , Madagascar and Argentina, Hypselosaurus and Aepisaurus from France, Macrurosaurus from England, Alamosaurus from United States , and Argyrosaurus , Antarctosaurus , and Laplatasaurus from Argentina. The material between them represented almost all regions of
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#17327974715677874-523: 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 titanosaurs had narrow-gauge limbs, with strong impressions of
8001-405: The end of the Jurassic and into the latest Cretaceous. Why this is remains unclear, but some similarities in feeding niches between iguanodontians, hadrosauroids and sauropods have been suggested and may have resulted in some competition. However, this cannot fully explain the full decline in distribution of sauropods, as competitive exclusion would have resulted in a much more rapid decline than what
8128-518: The evolutionary tree. Also, fragmentary fossils, of postcranial bones that differ from those of Epachthosaurus and skull bones that are dissimilar to the Sarmientosaurus cranium, show that in any case several titanosaur species were present in the habitat. Sarmientosaurus has an estimated length of twelve metres and a weight of ten tonnes. The describing authors indicated nine unique distinguishing traits, autapomorphies . The eye socket
8255-423: The external claw but also 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 Portugal 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
8382-411: The few groups of dinosaurs for which fossil eggs are known. The fossil site of Auca Mahuevo preserves a titanosaur nesting ground. Some titanosaur eggs have been found containing fossil embryos , which even preserve fossil skin. These fossil embryos are among the few titanosaur specimens to preserve complete skulls. Titanosauria have the largest range of body size of any sauropod clade, and includes both
8509-488: The flesh miss these facts, inaccurately depicting sauropods with hooves capping the claw-less digits of the feet, or more than three claws or hooves on the hands. The proximal caudal vertebrae are extremely diagnostic for sauropods. The sauropods' most defining characteristic was their size. Even the dwarf sauropods (perhaps 5 to 6 metres, or 20 feet long) were counted among the largest animals in their ecosystem . Their only real competitors in terms of size are
8636-601: 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. Sauropod tracks from the Villar del Arzobispo Formation of early Berriasian age in Spain support the gregarious behaviour of the group. The tracks are possibly more similar to Sauropodichnus giganteus than any other ichnogenera, although they have been suggested to be from
8763-483: The forefeet trackways being preserved. In a study published in PLoS ONE on October 30, 2013, by Bill Sellers , Rodolfo Coria , Lee Margetts et al. , Argentinosaurus was digitally reconstructed to test its locomotion for the first time. Before the study, the most common way of estimating speed was through studying bone histology and ichnology . Commonly, studies about sauropod bone histology and speed focus on
8890-418: The forefoot bone ( metacarpal ) 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
9017-441: The front joint processes and the vertebral centrum. A long and thin ossified tendon is running along the low side of the series of neck vertebrae and neck ribs. The skull has a length of forty-three centimetres. In top view the skull is more or less tongue-shaped. The antorbital fenestra is small but the eye socket is exceptionally large. In side view the snout is flat with a concave upper profile and surface. The maxilla touches
9144-401: The gait and speed of Argentinosaurus , the study performed a musculoskeletal analysis. The only previous musculoskeletal analyses were conducted on hominoids , terror birds , and other dinosaurs . Before they could conduct the analysis, the team had to create a digital skeleton of the animal in question, show where there would be muscle layering, locate the muscles and joints, and finally find
9271-500: The gigantic lognkosaurs . Fossils from perhaps the largest dinosaur ever found were discovered in 2021 in the Neuquén Province of northwest Patagonia, Argentina. It is believed that they are from a titanosaur. Some of smallest titanosaurs, such as Magyarosaurus , inhabited Europe, which was largely made up of islands during the Cretaceous, and were likely island dwarfs. Another taxon of tiny titanosaurs, Ibirania , lived
9398-551: The growth of sauropods, their theropod predators grew also, as shown by an Allosaurus -sized coelophysoid from Germany . Sarmientosaurus Sarmientosaurus is a genus of titanosaurian sauropod dinosaur belonging to the Titanosauria . It lived in what is now South America , specifically Argentina , during the Upper Cretaceous Period about 95 million years ago. The type species
9525-447: The head in such a posture for long would have used some half of its energy intake. Further, to move blood to such a height—dismissing posited auxiliary hearts in the neck —would require a heart 15 times as large as of a similar-sized whale. The above have been used to argue that the long neck must instead have been held more or less horizontally, presumed to enable feeding on plants over a wide area with less need to move about, yielding
9652-490: The history of their study, scientists, such as Osborn , 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 diplodocid Barosaurus lentus rearing up on its hind legs at the American Museum of Natural History is one illustration of this hypothesis. In a 2005 paper, Rothschild and Molnar reasoned that if sauropods had adopted
9779-512: The holotype of Futalognkosaurus and two undescribed specimens from Argentina. A fourth specimen, of an unidentified titanosaur from Brazil, preserves a nearly complete neck, with only the atlas , the tiny vertebra forming the joint between the skull and neck, missing. Only five titanosaur specimens preserve complete, articulated hind feet. This incompleteness is especially significant for giant titanosaurs, which are generally known from disarticulated and fragmentary remains. Titanosaurs are one of
9906-418: 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
10033-533: The largest dinosaur ever found were discovered in 2012 in the Neuquén Province of northwest Patagonia, Argentina. It is believed that they are from a titanosaur, which were amongst the largest sauropods. On or shortly before 29 March 2017 a sauropod footprint about 5.6 feet (1.7 meters) long was found at Walmadany in the Kimberley Region of Western Australia. The report said that it was the biggest known yet. In 2020 Molina-Perez and Larramendi estimated
10160-400: The largest known sauropods and some of the smallest. One of the largest titanosaurs, Patagotitan , had a body mass estimated to be 69 tonnes (76 tons), whereas one of the smallest, Magyarosaurus , had a body mass of approximately 900 kilograms (2,000 lb). Even relatively closely related titanosaurs could have very different body sizes, as the small rinconsaurs were closely related to
10287-462: The long necks would have cooled the veins and arteries going to the brain, avoiding excessively heated blood from reaching the head. It was in fact found that the increase in metabolic rate resulting from the sauropods' necks was slightly more than compensated for by the extra surface area from which heat could dissipate. When sauropods were first discovered, their immense size led many scientists to compare them with modern-day whales . Most studies in
10414-597: The makeup of the herds varied between species. Some bone beds, for example a site from the Middle Jurassic of Argentina , 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 Alamosaurus , Bellusaurus and some diplodocids . In
10541-413: The midline, separated by a narrow bone plate. The rear joint processes are uncommonly long, reaching beyond the edge of the vertebral body. The front joint processes are supported from below by struts with an oval cross-section, apparently formed by a perforation of the normally plate-shaped ridges in this position. The neck ribs are delicate, thin and rod-shaped. Parallel to the ribs, on the outer side of
10668-519: The most massive were Argentinosaurus (65–80 metric tons ), Mamenchisaurus sinocanadorum (60-80 metric tons ), the giant Barosaurus specimen (60-80+ metric tons ) and Patagotitan with Puertasaurus (50-55 metric tons ). Meanwhile, 'mega-sauropods' such as Bruhathkayosaurus has long been scrutinized due to controversial debates on its validity, but recent photos re-surfacing in 2022 have legitimized it, allowing for more updated estimates that range between 110–170 tons, rivaling
10795-641: The muscle properties before finding the gait and speed. The results of the biomechanics study revealed that Argentinosaurus was mechanically competent at a top speed of 2 m/s (5 mph) given the great weight of the animal and the strain that its joints were capable of bearing. The results further revealed that much larger terrestrial vertebrates might be possible, but would require significant body remodeling and possible sufficient behavioral change to prevent joint collapse. Sauropods were gigantic descendants of surprisingly small ancestors. Basal dinosauriformes, such as Pseudolagosuchus and Marasuchus from
10922-422: The naming of Titanosauria, Paul Upchurch in 1995 named the clade Titanosauroidea , to include Opisthocoelicaudia and the more derived Titanosauridae ( Malawisaurus , Alamosaurus and Saltasaurus ). United by: caudals with anteriorly-shifted neural spines, extremely robust forearm bones, a prominent concavity on the ulna for articulation with the humerus, a laterally flared and flattened ilium , and
11049-401: The nasal bones. Their teeth were either somewhat spatulate (spoon-like) or like pegs or pencils, but were always very small. Titanosaur necks were of average length for sauropods, and their tails were whip-like though not as long as in the diplodocids . While the pelvis was slimmer than some sauropods, the pectoral (chest) area was much wider, giving them a uniquely "wide-legged" stance. As
11176-405: The neck a cable-shaped structure was discovered with a constant diameter of three millimetres. It had an oval cross-section and a rough and striated surface. The structure originated directly behind the skull and continued over a length of several vertebrae, thus of some metres. It was interpreted by the describing authors as an ossified tendon . The alternative hypothesis that it might be a neck rib
11303-513: The neck an elongated structure was discovered that was identified as an ossified tendon. From the Bajo Barreal Formation another titanosaur sauropod is known, Epachthosaurus . It cannot be determined whether both taxa are identical because the material of their holotypes is not overlapping. However, the authors considered an identity as improbable because in their cladistic analysis both genera occupied different positions in
11430-431: The neck, and the head was evolved to be very small and light, losing the ability to orally process food. By reducing their heads to simple harvesting tools that got the plants into the body, the sauropods needed less power to lift their heads, and thus were able to develop necks with less dense muscle and connective tissue. This drastically reduced the overall mass of the neck, enabling further elongation. Sauropods also had
11557-448: The new genus Aeolosaurus , united by multiple features of the caudal vertebrae; the new clade Saltasaurinae was created to include Saltasaurus and the new genus Neuquensaurus , united by very distinct dorsals, caudals, and ilia; the new clade Antarctosaurinae was created to include Antarctosaurus , distinguished by large size, a different form of braincase , more elongate girdle bones, and more robust limb bones; and Argyrosaurinae
11684-720: The new genus name Iuticosaurus . The French taxon Aepisaurus was removed from the family and placed in undetermined Sauropoda. Macrurosaurus was considered a chimaera of titanosaurid and non-titanosaurid material because of the presence of both procoelous and amphicoelous caudals. Huene's species Titanosaurus lydekkeri was left as a nomen dubium , but left within Titanosauridae. Maastrichtian fossils from France and Spain were removed from Hypselosaurus and Titanosaurus , with Hypselosaurus being declared dubious like T. lydekkeri . The variety of Romanian fossils named as Magyarosaurus by Huene were also moved into
11811-584: The point it touched the ground. Mallison concluded that diplodocids were better adapted to rearing than elephants , 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). There is little agreement over how sauropods held their heads and necks, and the postures they could achieve in life. Whether sauropods' long necks could be used for browsing high trees has been questioned based on calculations suggesting that just pumping blood up to
11938-532: The postcranial skeleton, which holds many unique features, such as an enlarged process on the ulna , a wide lobe on the ilia , an inward-slanting top third of the femur , and an extremely ovoid femur shaft. Those features are useful when attempting to explain trackway patterns of graviportal animals. When studying ichnology to calculate sauropod speed, there are a few problems, such as only providing estimates for certain gaits because of preservation bias , and being subject to many more accuracy problems. To estimate
12065-441: The prefrontal. The jugal bone has an unusual L-shape with a very long front branch and an almost absent rear branch. The fifth cranial nerve , the nervus trigeminus , has extra exits for the branches towards the maxilla and the lower jaw, whereas other sauropods possess but single exit. The front of the lower jaw has an almost constant height. The praemaxilla bears four teeth, the maxilla eleven (right side) or twelve (left), and
12192-642: The prints. In titanosaurs, 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. Matthew Bonnan has shown that sauropod dinosaur long bones grew isometrically : that is, there was little to no change in shape as juvenile sauropods became gigantic adults. Bonnan suggested that this odd scaling pattern (most vertebrates show significant shape changes in long bones associated with increasing weight support) might be related to
12319-424: The relationships of titanosaurids to other sauropod groups couldn't be determined due to a lack of cranial material. A brief review of putative titanosaurids from Europe was authored by Jean Le Loeuff in 1993 , and covered the supposed genera known so far. The Barremian (middle Early Cretaceous) species Titanosaurus valdensis , named decades previous by Huene, was kept as the oldest of the titanosaurid and given
12446-437: The result of allopatric speciation and insular dwarfism . Some titanosaurs had osteoderms . Osteoderms were first confirmed in the genus Saltasaurus but are now known to have been present in a variety of titanosaurs within the clade Lithostrotia. The exact arrangement of osteoderms on the body of a titanosaur is not known, but some paleontologists consider it likely that the osteoderms were arranged in two parallel rows on
12573-597: The same location in India . While it was later given a position as a sauropod within Cetiosauridae by Lydekker in 1888 , he named the new sauropod family Titanosauridae for the genus in 1893 , which included only Titanosaurus and Argyrosaurus , united by procoelous caudals, opisthocoelous presacrals, a lack of pleurocoels and open chevrons. Following this, Austro-Hungarian paleontologist Franz Nopcsa reviewed reptile genera in 1928 , and provided
12700-413: The same species again, M. dacus as originally named by Nopcsa. José Bonaparte and Rodolfo Coria in 1993 concluded that a new clade of derived sauropods was necessary because Argentinosaurus , Andesaurus and Epachthosaurus were distinct from Titanosauridae as they possessed hyposphene-hypantrum articulations , but were still very closely related to the titanosaurids. The taxa that possessed
12827-621: The sauropods were huge. Their giant size probably resulted from an increased growth rate made possible by tachymetabolic endothermy , a trait which evolved in sauropodomorphs. Once branched into sauropods, sauropodomorphs continued steadily to grow larger, with smaller sauropods, like the Early Jurassic Barapasaurus and Kotasaurus , evolving into even larger forms like the Middle Jurassic Mamenchisaurus and Patagosaurus . Responding to
12954-401: The scientists, the specializing of their diets helped the different herbivorous dinosaurs to coexist. Sauropod necks have been found at over 15 metres (49 ft) in length, a full six times longer than the world record giraffe neck. Enabling this were a number of essential physiological features. The dinosaurs' overall large body size and quadrupedal stance provided a stable base to support
13081-451: The shorter hind legs free of the bottom, and using the front limbs to punt forward. However, due to their body proportions, floating sauropods would also have been very unstable and maladapted for extended periods in the water. This mode of aquatic locomotion , combined with its instability, led Henderson to refer to sauropods in water as "tipsy punters". While sauropods could therefore not have been aquatic as historically depicted, there
13208-409: 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 it is not clear if the most primitive sauropods, such as Vulcanodon and Barapasaurus , had such forefeet). The front feet were so modified in eusauropods that individual digits would not have been visible in life. The arrangement of
13335-477: The sister of Saltasaurus instead of the most basal titanosauroid. This result places Titanosauroidea in a group with Camarasaurus and Brachiosaurus , although Nemegtosauridae ( Nemegtosaurus and Quaesitosaurus ) was still classified as the basalmost family of diplodocoids. Upchurch chose to use Titanosauroidea as a replacement name for Titanosauria due to the recommended use of Linnean taxonomy and ranks. In 1997 , Leonardo Salgado et al. published
13462-477: The size estimates of A. fragillimus may have been highly exaggerated. The longest dinosaur known from reasonable fossils material is probably Argentinosaurus huinculensis with length estimates of 35 metres (115 ft) to 36 metres (118 ft) according to the most recent researches. However the giant Barosaurus specimen BYU 9024 might have been even larger reaching lengths of 45–48 meters (148–157 ft). The longest terrestrial animal alive today,
13589-537: The size of the animal at 31 meters (102 ft) and 72 tonnes (79.4 short tons) based on the 1.75 meter (5.7 ft) long footprint. 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 ( manus ). The front feet of sauropods were very dissimilar from those of modern large quadrupeds, such as elephants . Rather than splaying out to
13716-501: The skeleton, which showed they were derived sauropods Huene interpreted as closest to Pleurocoelus of the various non-titanosaurid genera. For his 1986 thesis, Argentinian paleontologist Jaime Powell described and classified many new genera of South American titanosaurs. Using the family Titanosauridae to include them all, he grouped the genera into Titanosaurinae, Saltasaurinae , Antarctosaurinae , Argyrosaurinae and Titanosauridae indet. Titanosaurinae included Titanosaurus and
13843-435: The skull was especially diplodocid-like due to square-shaped jaws; the titanosaur Antarctosaurus is especially similar to the rebbachisaurid Nigersaurus . Titanosaurs had small heads, even when compared with other sauropods. The head was also wide, similar to the heads of Camarasaurus and Brachiosaurus , though somewhat more elongated. Titanosaurian nostrils were large (" macronarian ") and all had crests formed by
13970-467: The surface of the water; in other words, they would float, and would not have been in danger of lung collapse due to water pressure when swimming. Evidence for swimming in sauropods comes from fossil trackways that have occasionally been found to preserve only the forefeet (manus) impressions. Henderson showed that such trackways can be explained by sauropods with long forelimbs (such as macronarians ) floating in relatively shallow water deep enough to keep
14097-418: The systematics of titanosaurs, Spanish paleontologist José Sanz et al. published an additional study in 1999 , utilizing both the names Titanosauria and Titanosauroidea in displaying their results. Similar to Upchurch (1995), Sanz et al. recovered Opisthocoelicaudia as a titanosauroid outside Titanosauria, while Titanosauria was redefined to include only the taxa classified by their study. Eutitanosauria
14224-434: The tip, narrow at the neck) teeth. They had tiny heads, massive bodies, and most had long tails. Their hind legs were thick, straight, and powerful, ending in club-like feet with five toes, though only the inner three (or in some cases four) bore claws. Their forelimbs were rather more slender and typically ended in pillar-like hands built for supporting weight; often only the thumb bore a claw. Many illustrations of sauropods in
14351-413: The tooth affected how long it took for a new tooth to grow. Camarasaurus 's teeth took longer to grow than those for Diplodocus because they were larger. It was also noted by D'Emic and his team that the differences between the teeth of the sauropods also indicated a difference in diet. Diplodocus ate plants low to the ground and Camarasaurus browsed leaves from top and middle branches. According to
14478-556: The town of Sarmiento . The specific name honours the late Eduardo Musacchio, an educator at the Universidad Nacional de la Patagonia San Juan Bosco . The Life Science Identifiers are 537DFE26-54EC-4978-AC86-E83A04FA74DE for the genus and C1090B8D-D051-44F3-B869-8B4A0C802176 for the species. The holotype , MDT-PV 2 , was found in the upper Lower Member of the Bajo Barreal Formation , dating from
14605-415: The wide-set hip bones of titanosaurs ) or would 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 brachiosaurids could rear up onto the hind legs, as their center of gravity was much farther forward than other sauropods, which would cause such
14732-433: The young reached adulthood. A 2014 study suggested that the time from laying the egg to the time of the hatching was likely to have been between 65 and 82 days. 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. Since early in
14859-424: Was all other titanosaurs. Titanosauria was additionally rediagnosed, with eye-shaped pleurocoels, forked infradiapophyseal laminae , centro-parapophyseal laminae, procoelous anterior caudals, and a significantly longer pubis than ischium . Titanosauridae was less strongly defined because of the polytomy between Malawisaurus and Epachthosaurus , so some diagnostic features couldn't be resolved. Saltasaurinae
14986-603: Was coined by Othniel Charles Marsh in 1878, and is derived from Ancient 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 extremely rare. Many species, especially the largest, are known only from isolated and disarticulated bones. Many near-complete specimens lack heads, tail tips and limbs. Sauropods were herbivorous (plant-eating), usually quite long-necked quadrupeds (four-legged), often with spatulate (spatula-shaped: broad at
15113-462: Was created for Argyrosaurus , bearing a more robust forelimb and hand and more primitive dorsals. The new genus Epachthosaurus was named for a more basal titanosaurid classified as Titanosauridae indet. along with unnamed specimens, Clasmodosaurus and Campylodoniscus . John Stanton McIntosh provided a synopsis of sauropod relationships in 1990 , using Titanosauridae as the group to contain all taxa like previous authors. Opisthocoelicaudia
15240-518: Was defined as the most recent ancestor of Neuquensaurus , Saltasaurus and its descendants, and diagnosed by short cervical prezygapophyses , vertically compressed anterior caudals, and a posteriorly shifted anterior caudal neural spine. Andesaurus Malawisaurus Epachthosaurus Argentinosaurus Opisthocoelicaudia Trigonosaurus (="Titanosaurinae indet. DGM Serie B") Aeolosaurus Alamosaurus Neuquensaurus Saltasaurus Contributing additional work to
15367-410: Was distinguished by pre- and post-spinal laminae in anterior caudals, a laterally flared ilium, a lateral expansion of the upper femur, and strongly opisthocoelous posterior dorsals. Less inclusive, Titanosauria was diagnosed by horizontally facing dorsal diapophyses , prominent procoelous anterior caudals, and a ridge on the sternal plates . Within Titanosauria, Eutitanosauria was characterized by
15494-672: Was placed in Opisthocoelicaudiinae within Camarasauridae , following its original description and not later works, and Nemegtosaurus and Quaesitosaurus were placed within Dicraeosaurinae . Titanosauridae included many previously named genera, plus taxa like Tornieria and Janenschia . Saltasaurus included the species previously known as Titanosaurus australis and T. robustus , which were named Neuquensaurus by Powell in 1986. McIntosh provided
15621-473: Was proposed as a name for the titanosaurs more derived than Epachthosaurus , and noted the presence of osteoderms as a probable synapomorphy of this clade. Aeolosaurus , Alamosaurus , Ampelosaurus and Magyarosaurus were looked at using their character list, but were considered too incomplete to add to the final study. Argentinian paleontologist Jaime Powell published his 1986 thesis in 2003 , with revisions to bring his old work up to date, including
15748-892: Was recognized early in the study of these animals, and, in fact, at least one sauropod specimen found in the 19th century ( Ornithopsis ) was originally misidentified as a pterosaur (a flying reptile) because of this. Some sauropods had armor . There were genera with small clubs on their tails, a prominent example being Shunosaurus , and several titanosaurs , such as Saltasaurus and Ampelosaurus , had small bony osteoderms covering portions of their bodies. A study by Michael D'Emic and his colleagues from Stony Brook University found that sauropods evolved high tooth replacement rates to keep up with their large appetites. The study suggested that Nigersaurus , for example, replaced each tooth every 14 days, Camarasaurus replaced each tooth every 62 days, and Diplodocus replaced each tooth once every 35 days. The scientists found qualities of
15875-508: Was rejected because the ribs are thicker and should have a different position. Such tendons might have been a continuation of the neck ribs, but again, its position did not confirm this. Instead, it was assumed to have been internal to some neck muscle. Such ossified tendons have never before been found in any fossil dinosaur but some extant bird groups such as the cranes show them, though they are relatively shorter, at most two vertebrae long. Possible muscles, where it could have been located, are
16002-492: Was relatively flexible, likely making them more agile than other sauropods, though at the expense of rearing on their hind legs compared to the Diplodocoids. One of the most characteristic features shared by most titanosaurs were their procoelous caudal vertebrae, with ball-and-socket articulations between the vertebral centra. The dorsal vertebrae of titanosaurs show multiple derived features among sauropods. Similarly to
16129-442: Was the longest sauropod known from reasonably complete remains, but others, like the old record holder, Diplodocus , were also extremely long. The holotype (and now lost) vertebra of Amphicoelias fragillimus (now Maraapunisaurus ) may have come from an animal 58 metres (190 ft) long; its vertebral column would have been substantially longer than that of the blue whale. However, research published in 2015 speculated that
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