According to the results of a new study, this agile creature attacked and retreated again and again, quite accurate beaten to his prey.

This is the first detailed investigation on the style of predatory attack by a member of an extinct group of large birds, flightless but with a scary skull and often huge dimensions.

These birds evolved about 60 million years, isolated in South America, an island-continent until the last few million years, and have branched out into about 18 known species of varying sizes. Most of them, the Kelenken, reaching 2.1 meters in height.

As these birds have no analogues among terrifying modern birds, their habits of life have been a mystery.

Now, a multinational team of scientists led by Frederick Degrange the Museo de La Plata (CONICET-dependent) in Argentina, has performed the most sophisticated study to date on the form, function and predatory behavior of a bird of that kind. The work has been carried out by computed tomography and advanced engineering methods. No one had done before.

The Andalgalornis lived in northwestern Argentina about six million years. It measured about 1.4 meters tall and weighed about 40 kilograms.

Like all birds of his kind, his skull was relatively large (37 cm), with a deep, narrow beak armed with a powerful hook like hawks.

Lawrence Witmer of Ohio University scanned by computed tomography Andalgalornis a full skull, and so the team got a picture of the internal architecture of it.

The scans revealed a Witmer, Degrange, Claudia Tambussi also the Museo de La Plata, and the rest of the team, what most distinguishes the other birds Andalgalornis his skull is very rigid.

Birds generally have skulls with great mobility between the bones, so they are lighter, while maintaining good strength.

But the research team found that these joints had become Andalgalornis mobile “rigid beams.”

The development of this weapon marrow, large and rigid, it was probably linked to the loss of flight in these birds, as well as sometimes gigantic size.