''Tastavinsaurus'' 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 ...

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 ...

belonging to the

Titanosauriformes Macronaria is a clade of sauropod dinosaurs. Macronarians are named after the large diameter of the nasal opening of their skull, known as the external naris, which exceeded the size of the orbit, the skull opening where the eye is located (hence ...

. It is based on a partial skeleton from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

Xert Formation The Calizas y margas de Xert Formation or Xert Formation is an Early Cretaceous (late Barremian) geologic formation of the Maestrazgo and Galve Basins in central-eastern Spain. The formation is described as a coastal claystone, with indications ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

. 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 ...

is ''Tastavinsaurus sanzi'', named in honor of the Rio Tastavins in Spain and Spanish paleontologist José Luis Sanz. ''Tastavinsaurus sanzi'' is known from two specimens, one from the

and one from the

Forcall Formation The Forcall Formation is an Early Cretaceous (Aptian) geologic formation in Spain. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.Weishampel, et al. (20 ...

. ''Tastavinsaurus'' was originally described as a somphospondylan, but it may be a brachiosaurid. The clade Laurasiformes was coined for ''Tastavinsaurus'' and its close relatives, which may include ''

Cedarosaurus ''Cedarosaurus'' (meaning "Cedar lizard" - named after the Cedar Mountain Formation, in which it was discovered) is a genus of nasal-crested macronarian dinosaur from the Early Cretaceous Period (Valanginian). It was a sauropod which lived in wha ...

'', ''

Soriatitan ''Soriatitan'' ("Soria titan") is a genus of brachiosaurid sauropod from the Early Cretaceous of Spain. It is known from one species, ''S. golmayensis'', found in the Golmayo Formation. It lived between 130 and 125 million years ago, and was id ...

'', and ''

Venenosaurus ''Venenosaurus'' ( ) is a genus of sauropod dinosaur that lived in what is now Utah during the Early Cretaceous. Its type and only species is ''Venenosaurus dicrocei''. Fossils of ''Venenosaurus'' were first discovered in 1998, by Denver Museum o ...

''.

Description

The length of ''Tastavinsaurus sanzi'' has been estimated to be 16 metres (50 feet), and its weight has been estimated to be 8 tonnes. The caudal vertebrae are similar to those of other basal titanosauriforms, such as ''Cedarosaurus''. The shin was proportionally shorter than in other sauropods, with the length 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 ...

being only 55% of the length of the

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

References

Macronaria Dinosaur genera Barremian dinosaurs Fossil taxa described in 2008 Dinosaurs of Spain {{Sauropodomorph-stub