Paleontological Site Arroio Cancela
Encyclopedia
The Paleontological Site Arroio Cancela is located within the city of Santa Maria, a municipality of Rio Grande do Sul
Rio Grande do Sul
Rio Grande do Sul is the southernmost state in Brazil, and the state with the fifth highest Human Development Index in the country. In this state is located the southernmost city in the country, Chuí, on the border with Uruguay. In the region of Bento Gonçalves and Caxias do Sul, the largest wine...
, the southernmost state of Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. The site is situated in the neighbourhood Nossa Senhora de Lourdes at an altitude of 107 metres above sea level. The fossils have been discovered within the sediments of the Santa Maria Formation
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It has a late Ladinian – early Carnian age , and is notable for its fossils of early dinosaurs, including the herrerasaur Staurikosaurus, the basal saurischian Teyuwasu, and the basal sauropodomorph...
, they are vertebrates from the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
period and are about 225 million years old.
This site is part of the Geopark Paleorrota
Paleorrota
Paleorrota , is a geopark located in the center of the Brazilian state of Rio Grande do Sul. The rocks and fossils found along the route date back to the times when there was only one supercontinent Pangaea....
and is easily accessible, because the Central Bus Station Station of Santa Maria is merely 600 Metres away. Only one hundred metres from the site, at the corner of the streets Irmão Donato and Otavio Alves de Oliveira, is the school State General Edson de Figueiredo and a nearby shopping centre.
Thirty-five metres higher in elevation (and stratigraphy) one finds the Paleontological Site Largo Padre Daniel Cargnin
Paleontological Site Largo Padre Daniel Cargnin
Paleontological Site Largo Padre Daniel Cargnin is a paleontological site of the Caturrita Formation located in the city of Santa Maria, Rio Grande do Sul, Brazil. The site is located in the Paleorrota Geopark....
and the Paleontological Site Bela Vista
Paleontological Site Bela Vista
Paleontological Site Bela Vista is located in the city of Santa Maria, Rio Grande do Sul, Brazil. And belongs to Caturrita Formation. Site belongs to the region paleorrota....
. At the Paleontological Site Largo Padre Daniel Cargnin
Paleontological Site Largo Padre Daniel Cargnin
Paleontological Site Largo Padre Daniel Cargnin is a paleontological site of the Caturrita Formation located in the city of Santa Maria, Rio Grande do Sul, Brazil. The site is located in the Paleorrota Geopark....
(Point 1, Figure 2) Cargnin collected a Therioherpeton cargnini and at the Paleontological Site Bela Vista
Paleontological Site Bela Vista
Paleontological Site Bela Vista is located in the city of Santa Maria, Rio Grande do Sul, Brazil. And belongs to Caturrita Formation. Site belongs to the region paleorrota....
(Point 2, Figure 2) fragments of an unidentified skull were discovered. The last two sites are close to the Cerrito hill and belong already to the Caturrita Formation
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 has a late Carnian to early Norian age and forms part of the Santa Maria Supersequence in the upper section of the Rosário do Sul Group.-Etymology:The...
.
Area under study
The encircled area comprises 9 hectares and is crossed by the stream (arroyo) Cancela starting at Osvaldo Aranha Street and flowing toward Fernando Ferrari Avenue. Along this stretch TriassicTriassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
vertebrate fossils are found within the exposed red sediments. The main collection points are listed as 1, 2 and 3 in Figure 2. The distance from point 1 to point 3 is 185 meters, whereas the distance from point 3 to Otavio Alves de Oliveira Street is 142 meters.
Description of collection points:
- Here a baby saurischianSaurischiaSaurischia meaning 'lizard' and ischion meaning 'hip joint') is one of the two orders, or basic divisions, of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two orders, based on their hip structure...
dinosaur was discovered in 1974, yet the exact species could not be determined. The animal measured approximately 70 cm head to tail. About 70% of the trunk bones were preserved, and about 50% of the skull bones. The vertebrae were still articulated and the entire column was present. The animal's head was rather small in relation to the body, with a long and thin tail. The teeth were rounded, not pointed as in carnivores. The taxon therefore probably was a herbivore. (This fossil was lost). - Here a RhynchosaurRhynchosaurRhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...
was unearthed in 1975, it had lost its skull, but from the rest of the body approximately 30 % of the bone material was preserved; its vertebrae were still articulated. (This fossil was also lost). Recently in 2005 a young RhynchosaurRhynchosaurRhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...
was discovered in the same location, whose vertebrae were dismembered. - Here four baby ExaeretodonExaeretodonExaeretodon is a genus of traversodontid cynodont; several species are known, from various formations. E. argentinus, E. frenguelli, and E. vincei are from the Carnian-age Ischigualasto Formation of Argentina. E. major and E. riograndensis are from the Ladinian-age portion of the Santa Maria...
s were found in 2004, with most of the trunk bones and the vertebrae being dismembered, which means that the animals had undergone an advanced state of dismemberment before being completely covered by sediments. In 2002 a RhynchosaurRhynchosaurRhynchosaurs were a group of Triassic diapsid reptiles related to the archosaurs.-Description:Rhynchosaurs were herbivores, and at times abundant , with stocky bodies and a powerful beak...
was discovered with approximately 60% of its torso preserved and the vertebrae still articulated. These fossils were donated to the UFRGS.