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68-551: Geological formation in Malawi Dinosaur Beds Stratigraphic range : Barremian–Aptian PreꞒ Ꞓ O S D C P T J K Pg N Type Geological formation Unit of Lupata Group Sub-units Lower Member, Upper Member Underlies Unconformity with Pliocene Chiwondo Beds Overlies Precambrian metamorphic basement Thickness Upper member

136-430: 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

204-471: 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:

272-502: 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

340-460: 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

408-422: 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

476-508: 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,

544-476: 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

612-484: 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

680-775: A proxy for the age at which a surface, such as an alluvial fan, was created. Burial dating uses the differential radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment was screened by burial from further cosmic rays exposure. Luminescence dating techniques observe 'light' emitted from materials such as quartz, diamond, feldspar, and calcite. Many types of luminescence techniques are utilized in geology, including optically stimulated luminescence (OSL), cathodoluminescence (CL), and thermoluminescence (TL). Thermoluminescence and optically stimulated luminescence are used in archaeology to date 'fired' objects such as pottery or cooking stones and can be used to observe sand migration. Incremental dating techniques allow

748-499: 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

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816-483: A reference for newly obtained poles for the rocks with unknown age. For paleomagnetic dating, it is suggested to use the APWP in order to date a pole obtained from rocks or sediments of unknown age by linking the paleopole to the nearest point on the APWP. Two methods of paleomagnetic dating have been suggested: (1) the angular method and (2) the rotation method. The first method is used for paleomagnetic dating of rocks inside of

884-463: 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

952-518: 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

1020-585: 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

1088-432: 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

1156-562: Is 210 m thick in the vicinity of the CD-9 locality. Fossil content [ edit ] Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon Notes Uncertain or tentative taxa are in small text ; crossed out taxa are discredited. Dinosaurs [ edit ] Sauropoda [ edit ] Plesiosaurs of

1224-470: Is 210 m (690 ft) thick in vicinity of CD-9 locality Lithology Primary Sandstone , siltstone , mudstone Location Coordinates 10°17′S 34°02′E  /  10.28°S 34.04°E  / -10.28; 34.04 Region Northern Region Country [REDACTED]   Malawi Extent Karonga District [REDACTED] [REDACTED] Dinosaur Beds (Malawi) The Dinosaur Beds

1292-850: Is a geological formation in Malawi whose strata date back to the Early Cretaceous . The age of the deposit is poorly constrained, but is likely to date from the Barremian to Aptian . Dinosaurs, turtles and crocodylomorphs remains are among the fossils that have been recovered from the formation. It is correlated with the Galula Formation in Tanzania . It consists of two members, a lower unfossiliferous member consisting of deep red stained sandstones, and an upper fossiliferous member consisting of white sands and grey to red mudstones and siltstones. The upper member

1360-691: Is also correct to say that fossils of the genus Tyrannosaurus have been found in the Upper Cretaceous Series. In the same way, it is entirely possible to go and visit an Upper Cretaceous Series deposit – such as the Hell Creek deposit where the Tyrannosaurus fossils were found – but it is naturally impossible to visit the Late Cretaceous Epoch as that is a period of time. Titanosauria Titanosaurs (or titanosaurians; members of

1428-491: Is also often used as a dating tool in archaeology, since the dates of some eruptions are well-established. Geochronology, from largest to smallest: It is important not to confuse geochronologic and chronostratigraphic units. Geochronological units are periods of time, thus it is correct to say that Tyrannosaurus rex lived during the Late Cretaceous Epoch. Chronostratigraphic units are geological material, so it

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1496-461: Is different in application from biostratigraphy, which is the science of assigning sedimentary rocks to a known geological period via describing, cataloging and comparing fossil floral and faunal assemblages. Biostratigraphy does not directly provide an absolute age determination of a rock, but merely places it within an interval of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand, however, to

1564-493: 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

1632-498: 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

1700-626: 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

1768-528: The Ar/ Ar dating method can be extended into the time of early human life and into recorded history. Some of the commonly used techniques are: A series of related techniques for determining the age at which a geomorphic surface was created ( exposure dating ), or at which formerly surficial materials were buried (burial dating). Exposure dating uses the concentration of exotic nuclides (e.g. Be, Al, Cl) produced by cosmic rays interacting with Earth materials as

1836-857: The Cretaceous Galula Formation and implications for vertebrate evolution" . Journal of African Earth Sciences . 139 : 403–420. Bibcode : 2018JAfES.139..403W . doi : 10.1016/j.jafrearsci.2017.11.029 . ISSN   1464-343X . ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 571-573. ISBN   0-520-24209-2 . ^ WINKLER, DALE A.; GOMANI, ELIZABETH M.; JACOBS, LOUIS L. (2000). "COMPARATIVE TAPHONOMY OF AN EARLY CRETACEOUS SAUROPOD QUARRY, MALAWI, AFRICA" . Paleont. Soc. Korea Special Publication . 4 : 99–114. ^ Gomani, E.M. 2005. Sauropod dinosaurs from

1904-709: The Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Karongasaurus K. gittelmani A titanosaurian sauropod . Malawisaurus M. dixeyi A lithostrotian titanosaur . Theropoda [ edit ] theropods of the Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Theropoda Indet. Indeterminate Crocodyliformes [ edit ] Crocodyliformes of

1972-544: The Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Malawisuchus M. mwakasyungutiensis A candidodontid notosuchian . Turtles [ edit ] Turtles of the Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Platycheloides P. nyasae A pelomedusid turtle . Amphibians [ edit ] Amphibians of

2040-813: The Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Anura Indet. Indetrminate Crutaceans [ edit ] Crustaceans of the Dinosaur Beds Genus Species Location Stratigraphic position Material Notes Images Hourcqia H. sp. A non-marine Ostracod . See also [ edit ] List of dinosaur-bearing rock formations List of fossiliferous stratigraphic units in Malawi References [ edit ] ^ Widlansky, Sarah J.; Clyde, William C.; O'Connor, Patrick M.; Roberts, Eric M.; Stevens, Nancy J. (March 2018). "Paleomagnetism of

2108-942: The Early Cretaceous of Malawi, Africa: Palaeontologia Electronica 8 (issue 1 - n. 27a): 37 pages. ^ Jacobs L. D. Winkler, Gomani E. (1993). "New material of an Early Cretaceous titanosaurid dinosaur from Malawi". Palaeontology . 36 (3): 523–534. Retrieved from " https://en.wikipedia.org/w/index.php?title=Dinosaur_Beds&oldid=1260236339 " Categories : Cretaceous paleontological sites of Africa Lower Cretaceous Series of Africa Cretaceous Malawi Aptian Stage Barremian Stage Sandstone formations Siltstone formations Mudstone formations Paleontology in Malawi Hidden categories: Articles with short description Short description matches Wikidata Pages using gadget WikiMiniAtlas Geochronology Geochronology

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2176-625: 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

2244-440: 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),

2312-409: The amount of radioactive decay of a radioactive isotope with a known half-life , geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods. More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With

2380-424: 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

2448-580: 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

2516-484: 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

2584-414: 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

2652-436: The construction of year-by-year annual chronologies, which can be fixed ( i.e. linked to the present day and thus calendar or sidereal time ) or floating. A sequence of paleomagnetic poles (usually called virtual geomagnetic poles), which are already well defined in age, constitutes an apparent polar wander path (APWP). Such a path is constructed for a large continental block. APWPs for different continents can be used as

2720-449: 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

2788-416: The exception of the radiocarbon method , most of these techniques are actually based on measuring an increase in the abundance of a radiogenic isotope, which is the decay-product of the radioactive parent isotope. Two or more radiometric methods can be used in concert to achieve more robust results. Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and

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2856-414: 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

2924-495: 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

2992-490: 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

3060-515: 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

3128-403: 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

3196-422: 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

3264-401: 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

3332-448: 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

3400-713: 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

3468-455: The point where they share the same system of naming strata (rock layers) and the time spans utilized to classify sublayers within a stratum. The science of geochronology is the prime tool used in the discipline of chronostratigraphy , which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies . By measuring

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3536-425: 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

3604-438: 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

3672-426: The same age and of such distinctive composition and appearance that, despite their presence in different geographic sites, there is certainty about their age-equivalence. Fossil faunal and floral assemblages , both marine and terrestrial, make for distinctive marker horizons. Tephrochronology is a method for geochemical correlation of unknown volcanic ash (tephra) to geochemically fingerprinted, dated tephra . Tephra

3740-700: The same continental block. The second method is used for the folded areas where tectonic rotations are possible. Magnetostratigraphy determines age from the pattern of magnetic polarity zones in a series of bedded sedimentary and/or volcanic rocks by comparison to the magnetic polarity timescale. The polarity timescale has been previously determined by dating of seafloor magnetic anomalies, radiometrically dating volcanic rocks within magnetostratigraphic sections, and astronomically dating magnetostratigraphic sections. Global trends in isotope compositions, particularly carbon-13 and strontium isotopes, can be used to correlate strata. Marker horizons are stratigraphic units of

3808-589: 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

3876-414: 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

3944-478: 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

4012-502: 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

4080-437: 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

4148-418: 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

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4216-424: 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

4284-463: 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

4352-519: 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

4420-410: 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

4488-651: 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

4556-474: 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

4624-486: 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

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