The Paleontological Site Arroio Cancela is located within the city of Santa Maria, a municipality of Rio Grande do Sul, the southernmost state of Brazil.

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, they are vertebrates from the Triassic period and are about 225 million years old.

At the Paleontological Site Largo Padre Daniel Cargnin (Point 1, Figure 2) Cargnin collected a Therioherpeton cargnini and at the Paleontological Site Bela Vista (Point 2, Figure 2) fragments of an unidentified skull were discovered.

The circled area comprises 9 hectares and is crossed by the stream (arroyo) Cancela starting at Osvaldo Aranha Street and flowing toward Fernando Ferrari Avenue.