''Sacisaurus'' (" Saci lizard") is a

silesaurid Silesauridae is an extinct family of Triassic dinosauriforms. It is most commonly considered to be a clade of non-dinosaur dinosauriforms, and the sister group of dinosaurs. Some studies have instead suggested that most or all silesaurids compri ...

dinosauriform from the

Late Triassic The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. ...

( Norian)

Caturrita Formation The Caturrita Formation is a rock formation found in Rio Grande do Sul, Brazil. Its sediments were deposited in the Paraná Basin. The formation is from the Upper Triassic and forms part of the Santa Maria Supersequence in the upper section of th ...

of southern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. The scientific name, ''Sacisaurus agudoensis'', refers to the city where the species was found, Agudo in the Rio Grande do Sul state, whereas ''Sacisaurus'' refers to Saci, a famous one-legged creature from Brazilian mythology, because among the dozens of

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 preserved ...

material unearthed, 35 right femora were collected whereas only 1 left

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates wit ...

was found.

Characteristics

''Sacisaurus'' was approximately long and high, based on the largest femoral specimen. Some elements that were originally mentioned in the description study were reassigned to other taxa afterwards. Its long and strong legs indicate that it was a fast animal. The biggest teeth of the genus were just long. Sacisaurus-mingau

The well-preserved

jaw The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...

indicates that ''Sacisaurus'' was an herbivore, and there is a process at the tip that resembles the ornithischian

predentary Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek st ...

bone. Further research attempted to define if ''Sacisaurus'' was the oldest ornithischian dinosaur. In 2011, a

cladistic analysis Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived chara ...

of some of its morphological particularities found that its closest relative was the silesaurid ''

Diodorus Diodorus Siculus, or Diodorus of Sicily ( grc-gre, Διόδωρος ; 1st century BC), was an ancient Greek historian. He is known for writing the monumental universal history ''Bibliotheca historica'', in forty books, fifteen of which su ...

''.Christian F. Kammerer, Sterling J. Nesbitt, and Neil H. Shubin (2011) The first basal dinosauriform (Silesauridae) from the Late Triassic of Morocco. Acta Palaeontologica Polonica (in press)

History

''Sacisaurus'' was discovered in 2001 in the small municipality of Agudo, in the countryside of Rio Grande do Sul state. With 50 bones, scientists assembled the skeleton and speculated on how the animal might have lived. The fossil was presented for the first time in the 2nd Latin American Congress of Vertebrate Paleontology in 2005. . After the work of Brazilian scientists, the announcement of the discovery of the new species was made on November 1, 2006 at the

University of São Paulo The University of São Paulo ( pt, Universidade de São Paulo, USP) is a public university in the Brazilian state of São Paulo. It is the largest Brazilian public university and the country's most prestigious educational institution, the bes ...

Ribeirão Preto Ribeirão Preto (Portuguese pronunciation: �ibejˈɾɐ̃w ˈpɾetu is a municipality and a metropolitan area located in the northeastern region of São Paulo state, Brazil. Ribeirão Preto is the eighth-largest municipality in the State wit ...

, where the bones were identified and the paper was published in the British scientific journal ''Historical Biology: A Journal of Paleobiology'' on October 30, 2006. The discovery helped scientists to study the feeding habits of dinosaurs and their close relatives, since it is one of the oldest ever found.

References

External links

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Folha online - Brasil "ganha" dinossauro de 220 milhões de anos
{{Taxonbar, from=Q2700764 Silesaurids Norian genera Late Triassic reptiles of South America Triassic Brazil Fossils of Brazil Paraná Basin Fossil taxa described in 2006