Name Sacisaurus
Class Ornithodiran
Period Late Triassic
Location Brazil

Sacisaurus agudoensis is an Ornithodiran from late Triassic Brazil.



Sacisaurus was approximately 1.5 metres (4.9 ft) long and 70 centimetres (2.3 ft) high. Its long and strong legs indicate that it was a fast animal. According to Jorge Ferigolo, paleontologist of Zoobothanic Foundation of Rio Grande do Sul state, the biggest teeth of the genus were just 3 millimetres (0.12 in) long.

The well-preserved jaw indicates that Sacisaurus was an herbivore, and there is a process at the tip that resembles the ornithischian predentary bone. Further research attempted to define if Sacisaurus was the oldest ornithischian dinosaur. In 2011, a cladistic analysis of some of its morphological particularities found that its closest relative was the silesaurid Diodorus.


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, Ribeirão Preto, 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.

Sacisaurus by cisiopurple ddzrcqq-pre

Size comparison