Gurilynia

Gurilynia is known from only three partial bones: the top end of a right upper arm bone, the bottom end of a left upper arm bone, and the shoulder end of a left coracoid.1

It was the largest bird ever found from the Cretaceous period in Mongolia, weighing about 2.1 kilograms (4.6 pounds).1

The head of its upper arm bone was about 29 millimeters (1.1 inches) wide, much bigger than that of Pengornis, the largest Early Cretaceous enantiornithine.1

Gurilynia belonged to a group of ancient birds called enantiornithines, which had teeth and claws on their wings.1

It lived between 70 and 66 million years ago, right before the mass extinction that wiped out the non-avian dinosaurs.1

The fossils were found in the Nemegt Formation, which was a wet floodplain with rivers and forests during the Late Cretaceous.1