It was a giant bird with claws on which it rested two fingers. He hunted on the Atlantic coasts of the Argentine province of Río Negro (south). It would be a specimen not yet registered, according to a statement from the National Council for Scientific and Technical Research (Conicet). The giant bird of Argentina lived 8 million years ago.
«They are the first footprints that we know are from the group of terror birds or fororracos. They are not known anywhere else in the world. This discovery will facilitate its recognition in other regions,” explained Ricardo Melchor. He is a CONICET researcher in charge of the study.
ancient desert
The animal was named Rionegrina pozosaladensis. She would weigh a minimum of 55 kilos and at the time of leaving the tracks she was moving slowly through the area. She added that they show a large central finger and a lateral finger, which would be the main support. They have, in turn, a very reduced inner toe and almost no heel support is seen.
These characteristics of the foot indicate marked adaptations for running. They correspond to a running bird. «It has a large claw on the inner finger. “It would serve to immobilize the prey, just as the current chuñas do,” said the scientist. The footprints about 40 centimeters long were found by an environmental guard. It appeared in a protected natural area called Pozo Salado. Eight million years ago it was a desert environment with rocks and lakes that functioned as oases.
About 400 images were taken of the set of footprints and a sample of volcanic ash that was above the tracks. Its age was determined with a geochemical analysis. These footprints are different from those of current or fossil rheas because they support three toes.
Footprints on Earth
«The only large ratite birds are the extinct group of the ‘terror birds’ or fororracos. Its record is extensive in Argentina,” explained the scientist.
Fossils of the bird that preceded Rionegrina, discovered in 2007 and called Kelenken, were also found in the province. But it was ruled out that they were his fingerprints. Its weight was greater than 200 kilos, so the trail would be larger, they added. The giant bird from Argentina left its own mark, to be found 8 million years later.
