''Llallawavis scagliai'' (magnificent bird of Scaglia) is a large, extinct predatory

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

from Pliocene Argentina. Its fossil is the most complete fossil of a

phorusrhacid Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal ...

(or "terror bird") yet found.

Description

The fossil, discovered in 2010 in sediment among the cliffs above La Estafeta beach in the lower part of the Playa Los Lobos Allo Formation, contains the complete palate, complete trachea, skull, voice box, and eye bones. The fossil shows ''L. scagliai'' was a medium-sized phorusrhacid around tall and lived in Argentina approximately 3.5 million years ago during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58

Habitat

''Llallawavis scagliai'' likely roamed in grassland and weighed around . The joints separating the skulls bones were fused, unlike modern birds, and that may have helped it batter prey. CT scans of its inner ear show that it could only hear frequencies between about 380 and 4230 hertz, and probably had a deep voice to match. The below cladogram is simplified after the analysis of Degrange ''et al.'' (2015).

References

{{Taxonbar, from=Q19792280 Phorusrhacidae Pliocene birds of South America Chapadmalalan Neogene Argentina Fossils of Argentina Fossil taxa described in 2015