| Named By: | D. A. Campos, A. W. A. Kellner, R. J. Bertini, & R. M. Santucci in 2005 |
| Time Period: | Late Cretaceous |
| Location: | Brazil - Marilia Formation |
| Size: | Unknown due to lack of remains |
| Diet: | Herbivore |
| Fossil(s): | Partial post cranial remains including left ilium, six sacral (hip) vertebrae, ten dorsal (back) vertebrae and one caudal (tail) vertebrae (MCT 1488-R). A further ten vertebrae that may actually belong to the same individual were later added (MCT 1719-R) |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Sauropoda | Titanosauria | Titanosauridae | |
Trigonosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now Brazil. The type species, Trigonosaurus pricei, was first described by Campos, Kellner, Bertini, and Santucci in 2005. It is based on two specimens, both consisting mainly of vertebrae. Before its description, it was known as the "Peiropolis titanosaur", after the place it was found.