Herrerasaurid dinosaurs lived throughout the Carnian age of the Late Triassic date, approximately 230 million years back.

They were bipedal hunters with serrated teeth and big claws on their hands, and some grew longer than 5 m (16 feet).

The group is understood just from South America, from fossils discovered in Argentina and Brazil.

Previously, herrerasaurids in both nations had actually come just from rock layers controlled by rhynchosaurs, stocky plant-eating reptiles.

More youthful layers, where a pig-sized cynodont family member of mammals called Exaeretodon ended up being more plentiful and rhynchosaurs decreased, had actually produced none.

The lack raised the possibility that herrerasaurids passed away out when the animals moved.

“The lack of herrerasaurid records from strata defined by abundance of Exaeretodon might show faunal modifications that eventually avoided the determination of the group,” stated Dr. Rodrigo Temp Müller, a paleontologist at the Universidade Federal de Santa Maria.

“For example, if herrerasaurids were environmentally specialized for preying upon rhynchosaurs, the decrease of these herbivores might have adversely impacted their survival.”

“However, although rhynchosaurs end up being less plentiful in these more youthful assemblages, they are not missing from the animals.”

“Consequently, this alone might not sufficiently discuss the evident lack of herrerasaurids from these deposits.”

In the research study, Dr. Müller took a look at a piece of a herrerasaurid pubis (hip bone) that was gathered at a website near the town of Agudo in Rio Grande do Sul, Brazil.

Catalogued as CAPPA/UFSM 0539, the fossil is the very first herrerasaurid record from rock layers where Exaeretodon is plentiful.

“The specimen was gathered from the Várzea do Agudo website, situated in the town of Agudo, Rio Grande do Sul, Brazil,” Dr. Müller stated.

“The fossil-bearing strata at this website come from the Santa Maria Formation, Paraná Basin.”

The author recommends that herrerasaurids were versatile sufficient to endure in altered communities, which they might have been the leading predators at the website.

He likewise raises the possibility that this is the youngest herrerasaurid understood, however just if the Brazilian rocks are more youthful than other herrerasaurid-bearing layers, as they remain in Argentina.

“Absolute dating of the Brazilian strata stays vital to develop a more reputable sequential structure for the various Triassic fossil-bearing areas,” the scientist stated.

The research study was released on October 19, 2026 in The Science of Nature

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R.T. Müller. 2026. Incident of a herrerasaurid dinosaur in a traversodontid cynodont-dominated Late Triassic animals of southern Brazil. Sci Nat 113, 133; doi: 10.1007/ s00114-026-02185-1