''Uberabatitan'' (meaning "

Uberaba Uberaba () is a municipality in the state of Minas Gerais, Brazil. It is located in the Brazilian Highlands at an elevation of 823 metres (2,700 ft) above sea level on the Uberaba River, and is situated 418 kilometres (260 mi) from the state c ...

titan", in reference to where it was found) is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

titanosaur 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 thr ...

ian

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. It is known from bones including neck, back, and tail

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

pelvic bones The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the ilium, isch ...

, and limb bones. These

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s were found in the uppermost portion of the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

-age

Serra da Galga Formation The Serra da Galga Formation is a geological formation in Minas Gerais state of southeastern Brazil. Its strata date back to the Maastrichtian, and are part of the Bauru Group. It was originally considered a member of the Marília Formation. Di ...

of the Bauru Group, in Uberaba,

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, described by Salgado and Carvalho in 2008, is ''U. ribeiroi''. To date, it is the most recent titanosaur from Bauru Group rocks; other titanosaurs from the Bauru Group, including '' Baurutitan'' and '' Trigonosaurus'', come from lower (thus older) levels.

Discovery and naming

''Uberabatitan ribeiroi'' was named by

Leonardo Salgado Leonardo Salgado is an Argentine palaeontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossi ...

and Ismar de Souza Carvalho in 2008, based on specimens found at a road cut along Federal Highway BR-050 in

. The genus name refers to Uberaba and the species name honors Luiz Carlos Borges Ribeiro, the director of the Centro de Pesquisas Paleontológicas Lewellyn Price, for his support.

Fossil record

Fossils of ''Uberabatitan ribeiroi'' have been found in the

. All the specimens attributed to ''U. ribeiroi'' were found in a single quarry, and have been accessioned at the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price (CPPLIP) at the

Federal University of Triângulo Mineiro The Federal University of Triângulo Mineiro ( or UFTM) is a public university located in the city of Uberaba, Minas Gerais, Brazil, formerly FMTM (Faculty of Medicine of the Triângulo Mineiro) and transformed into a university in 2005 by a fede ...

. More than sixty bones have been found, representing the intermingled remains of at least five individuals of various sizes and ages, with both immature and mature individuals represented. These remains include cervical,

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

, sacral, and

caudal vertebrae Caudal vertebrae are the vertebrae of the tail in many vertebrates. In birds, the last few caudal vertebrae fuse into the pygostyle, and in apes, including humans, the caudal vertebrae are fused into the coccyx. In many reptiles, some of the caud ...

chevrons Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * '' Eulithis testata'', a moth * Chevron (geology), a fold in rock la ...

, and portions of the shoulders, hips, and limbs. As is commonly the case in titanosaurs, the skull is not known. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

consists of the

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

(CPPLIP-912),

fibula The fibula (: fibulae or fibulas) or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. ...

(CPPLIP-1107), and

astragalus Astragalus may refer to: * ''Astragalus'' (plant), a large genus of herbs and small shrubs *Astragalus (bone) The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known ...

(CPPLIP-1082) of a single individual; other elements had initially been included in the holotype as well, but were excluded due to the lack of evidence that they came from the same individual. Another specimen from the Serra da Galga Formation, MCT 1487-R, also known as "DGM Series A", exhibits close similarities to ''Uberabatitan'' and may belong to it, or at least a close relative. MCT 1487-R consists of a nearly complete neck, one of the few known for any titanosaur. Two teeth found at the ''Uberabatitan'' site, and others found elsewhere in the Serra da Galga Formation, may also belong to ''Uberabatitan ribeiroi''; one of these teeth, CPPLIP-1166, is the largest titanosaur tooth ever found, with a

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...

high from its base to its apex.

Description

As a

, ''Uberabatitan'' would have been a large, quadrupedal herbivore with a long neck. It has been estimated that ''Uberabatitan ribeiroi'' could reach a length of , although most known specimens are of much smaller individuals. Although the skull of ''Uberabatitan'' is unknown, it may belong to a clade of titanosaurs that were characterized by a broad, squared-off snout. The teeth possibly referable to ''Uberabatitan'' are slender and chisel-like, as in other titanosaurs. As in many other sauropods, ''Uberabatitan'' had hyper-elongate cervical ribs, much of the length of which was formed by

ossified tendons A tendon or sinew is a tough band of dense fibrous connective tissue that connects muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tension. Tendons, like ligaments, are made of ...

. The

and

of ''Uberabatitan'' exhibit some taxonomically significant traits. The tibia has a robust lateral protuberance that articulates with a medial knob on the fibula, which is an

autapomorphy In phylogenetics, an autapomorphy is a distinctive feature, known as a Synapomorphy, derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or Outgroup (cladistics), outgroup taxa, not ...

of ''Uberabatitan ribeiroi''. As in ''Laplatasaurus'', but unlike most titanosaurs, there is a concave surface behind the lateral tuberosity of the fibula.

Classification

Phylogenetic position of ''Uberabatitan'' in an analysis by Silva and colleagues in 2019: Possible close relatives of ''Uberabatitan'' include '' Laplatasaurus'' and ''

Brasilotitan ''Brasilotitan'' (meaning "Brazil giant") is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous (early Maastrichtian) Adamantina Formation of Brazil. The type species is ''Brasilotitan nemophagus''. ''Brasilotitan'' was a small ti ...

''. Gallina and Otero recovered '' Laplatasaurus'' as the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of ''Uberabatitan'' in an analysis that did not include ''Brasilotitan''. Navarro and colleagues and Filippi and colleagues have recovered ''

'' as the sister taxon of ''Uberabatitan'' in analyses that did not include ''Laplatasaurus''. Silva and colleagues regarded a close relationship between ''Uberabatitan'' and ''Brasilotitan'' "possible"; their analysis recovered a polytomy of ''Brasilotitan'', ''Uberabatitan'', and a clade containing other members of

Aeolosaurini Aeolosaurini is an extinct clade of titanosaurian dinosaurs known from the Cretaceous period of Argentina and Brazil. Rodrigo M. Santucci and Antonio C. de Arruda-Campos (2011) in their cladistic analysis found ''Aeolosaurus'', '' Gondwanatitan'' ...

. In an analysis that included neither ''Laplatasaurus'' nor ''Brasilotitan'', ''Uberabatitan'' was recovered as a member of Aeolosaurini most closely related to '' Bravasaurus'', '' Gondwanatitan'', and '' Trigonosaurus''.

Paleobiology

''Uberabatitan'', like other sauropods, underwent rapid, uninterrupted growth early in life. Individuals closer to maturity would have transitioned to cyclical growth, with periodic slowdowns in their growth rate.

Notes

References

{{Taxonbar, from=Q136460 Titanosauria Dinosaur genera Maastrichtian dinosaurs Fossil taxa described in 2008 Dinosaurs of Brazil