''Mendozasaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of titanosaurian

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 ...

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

. It was a member of Titanosauria, which were massive sauropods that were common on the southern landmasses during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

. It is represented by several partial skeletons from a single locality within the

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded b ...

(lower Upper Cretaceous) Sierra Barrosa Formation in the south of Mendoza Province, northern

Neuquén Basin Neuquén Basin ( es, Cuenca Neuquina) is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The ba ...

, Argentina. The

type species In 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 species that contains the biological type specimen( ...

, ''Mendozasaurus neguyelap'', was described by Argentine paleontologist Bernardo Javier González Riga in 2003. ''Mendozasaurus'' is the first dinosaur named from

Mendoza Province Mendoza, officially Province of Mendoza, is a province of Argentina, in the western central part of the country in the Cuyo region. It borders San Juan to the north, La Pampa and Neuquén to the south, San Luis to the east, and the republic ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

, for which it was named.

Description

This species belonged to the discovered clade

Lognkosauria Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. Description Lognkosaurians can be distinguished from other titanosaurs by the wide and u ...

, a transitional group of titanosaurs which included the gigantic ''

Futalognkosaurus ''Futalognkosaurus'' ( ; meaning "giant chief lizard") is a genus of titanosaurian dinosaur. The herbivorous ''Futalognkosaurus'' lived approximately 87 million years ago in the Portezuelo Formation, in what is now Argentina, of the Coniacian s ...

'' and ''

Puertasaurus ''Puertasaurus'' is a genus of sauropod dinosaur that lived in South America during the Late Cretaceous Period. It is known from a single specimen recovered from sedimentary rocks of the Cerro Fortaleza Formation in southwestern Patagonia, Arge ...

''. Like both of these animals, ''Mendozasaurus'' had a long neck with very wide cervical neural spines. Holtz estimated its length at . In 2010 Gregory S. Paul estimated ''Mendozasaurus'' at 20 meters (65.6 feet) in length and 16 tonnes (17.6 short tons) in weight.

Classification

A phylogenetic analysis conducted by González Riga and colleagues in 2018 recovered ''Mendozasaurus'' as the most basal member of Lognkosauria, including ''Futalognkosaurus'' and the gigantic titanosaurs ''

Argentinosaurus ''Argentinosaurus'' is a genus of giant sauropod dinosaur that lived during the Late Cretaceous period in what is now Argentina. Although it is only known from fragmentary remains, ''Argentinosaurus'' is one of the largest known land animals o ...

'', '' Notocolossus'', ''

Patagotitan ''Patagotitan'' is a genus of titanosaurian sauropod dinosaur from the Cerro Barcino Formation in Chubut Province, Patagonia, Argentina. The genus contains a single species known from multiple individuals: ''Patagotitan mayorum'', first announc ...

'' and ''Puertasaurus''. The following

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

shows the position of ''Mendozasaurus'' in

according to González Riga and colleagues, 2018.

References

External links

Sauropod dinosaurs
Complementary information on South American titanosaurs Lithostrotians Coniacian life Late Cretaceous dinosaurs of South America Cretaceous Argentina Fossils of Argentina Neuquén Basin Fossil taxa described in 2003 {{Sauropodomorph-stub

Description

Classification

References

Further reading

External links