Phorusracids, or “terror birds” were three to 10 foot tall, flightless, predatory birds that struck fear into the hearts of small animals in South America during the Cenozoic Age. Now the most perfectly preserved specimen of a terror bird found to date has introduced scientists to a new species and shed light on the lives of one of history’s fiercest predators.
The fossilized remains of Llallawavis scagliai (“Scaglia’s Magnificent Bird”) is described in the latest issue of the Journal of Vertebrate Palaeontology.
According to the researchers, 90 percent of the skeleton was perfectly preserved. The auditory region of the animals skull, its voice box, trachea, the complete palate, and the bones for focusing the eye were all preserved in every detail. It is the first time that structures which indicate hearing sensitivity have been available for study from any terror bird.
The find could help to explain the behaviour, evolution and ecology of the animals and allow scientists to learn a great deal about how the animal experienced and interacted with the world.
“The mean hearing estimated for this terror bird was below the average for living birds. This seems to indicate that Llallawavis may have had a narrow, low vocalization frequency range, presumably used for intraspecific acoustic communication or prey detection,“ said Dr. Federico “Dino” Degrange, lead author of the study from the Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET and the Universidad Nacional de Córdoba, Argentina in a statement.
”The discovery of this new species provides new insights for studying the anatomy and phylogeny of phorusrhacids and a better understanding of this group’s diversification,” said Dr. Claudia Tambussi, also of CICTERRA and one of the co-authors of the study.
The animal was about 4 feet tall and lived in what is now Argentina about 3.5 million years ago during the Pliocene Epoch close the the time that the terror birds became extinct.
“The discovery of this species reveals that terror birds were more diverse in the Pliocene than previously thought. It will allow us to review the hypothesis about the decline and extinction of this fascinating group of birds” said Degrange.
The birds were almost entirely found in South America, however, a few examples have been found in Texas and Florida so, apparently, ranged to some extent through central and southern North America.
In the current environment it can be hard to imagine a bird as a fierce predator unless you imagine them at several times their current size. The terror bird looked something like a 10 foot tall ostrich, with an eagles head and a massive, hooked beak like a pickaxe.
Although they are nowhere near as intimidating, the only known living descendent of the phorusrhacids are the black-legged and red-legged seriemas of of Brazil, Bolivia, Argentina, Paraguay and Uruguay.
