Holotype trackway of Rionegrina pozosaladensis igen. et isp. nov. (a–c) Orthomosaic, digital elevation model and interpretative drawing of the holotype. (d,e) Detail of orthomosaic and digital ...

When Antarctica was lush with forests during the Eocene, there was a carnivorous bird that had a curved beak and terrifying claws. The terror bird — an extinct ...

In the vast plains of ancient South America, millions of years ago, a menacing shadow loomed over the grasslands. It wasn’t a dinosaur or a mammalian predator, but a colossal bird that dominated the ...

Millions of years ago, apex predators in the Phorusrhacidae family lived up to their more common name—terror birds. The mostly flightless, meat-eating dinosaur descendents were the size of dogs at ...

Prehistoric Earth was filled with all kinds of impressively scary animals. But one category of avians, an extinct clade called Phorusrhacidae, was so fierce that they ...