Photo/Illutration An artist’s rendition of a new carnivorous dinosaur species called Maip macrothorax that was unearthed in Argentina ((C) Agustin Ozain)

An international research team has identified a new dinosaur species in Argentina, an apex predator so ferocious that it was named after an evil spirit from a local myth.

Maip macrothorax, the largest relative of Megaraptora found so far, was discovered through bones from its spinal column and ribs unearthed from a stratum formed 70 million years ago in what is now Santa Cruz province, southern Argentina, in March 2020.

“Based on the discovery of Maip macrothorax, combined with other finds, it appears that Megaraptora came to hold one of the top spots among carnivores in South America by the end of the Cretaceous Period,” said Makoto Manabe, deputy director of the National Museum of Nature and Science in Tokyo.

Manabe and Takanobu Tsuihiji, a chief researcher at the museum, were involved in the dinosaur study.

Maip macrothorax, a theropod, was an estimated 9 meters long and weighed 5 tons. Like other Megaraptora, the new species probably had many teeth in its elongated head as well as sharp claws on its forearms.

According to the team, “Maip” refers to an evil spirit in Patagonian lore that freezes people to death with chilly winds. “Macrothorax” was used in the name to describe the beast’s large chest cavity, estimated at 1.2 meters wide.

Manabe, Tsuihiji and Dr. Fernando Novas at the Argentine Natural Science Museum concluded the remains were from a previously unknown species based on the bones’ shapes and density levels.

Megaraptora roamed the southern hemisphere in the late Cretaceous Period. The carnivore is believed to have resembled the Tyrannosaurus that dominated the northern hemisphere.

The findings of the international research team were published in the science journal Scientific Reports at (

The remains of Maip macrothorax are expected to go on display at a special dinosaur exhibition scheduled for 2023 at the Japanese museum.

Images and locations of confirmed fossils of Maip macrothorax (Provided by the National Museum of Nature and Science)