A group of paleontologists has described a new genus and species of Phorusrhacidae that lived in what is now Argentina during the Pliocene epoch, around 3.5 million years ago.
Llallawavis scagliai. Image credit: H. Santiago Druetta.
Phorusrhacidae (the so-called terror birds) were a group of extinct terrestrial carnivorous birds that are known mainly from the Cenozoic of South America, but also from the Plio-Pleistocene of North America and the Eocene of Africa.
These birds had a very large body mass, up to 70 kg, and were 0.9 – 2 meters in height.
They were the predominant predators during the Cenozoic and certainly one of the most striking groups that lived during that period.
The new species, named the Scaglia’s Magnificent Bird, is the most complete terror bird ever discovered, with almost 100 percent of the skeleton exquisitely preserved.
The scientific name of the bird is Llallawavis scagliai. Llallawa means magnificent in the Quechua language in reference to the nature of the terror bird’s remains, and avis means bird.
The species name honors Galileo Juan Scaglia (1915–1989), naturalist and director of the Museo Municipal de Ciencias Naturales Lorenzo Scaglia in Buenos Aires, Argentina, during 1940–1980.
Skeleton of Llallawavis scagliai. Image credit: M. Taglioretti / F. Scaglia.
Llallawavis scagliai is a medium-sized terror bird with an estimated body mass of 18 kg and estimated height of 1.2 m
According to the paleontologists, the specimen reveals details of anatomy that rarely preserve in the fossil record, including the auditory region of the skull, voice box, complete trachea, bones for focussing the eye, and the complete palate, allowing an unprecedented understanding of the sensory capabilities of terror birds.
“The mean hearing estimated for this terror bird was below the average for living birds. This seems to indicate that Llallawavis scagliai may have had a narrow, low vocalization frequency range, presumably used for intraspecific acoustic communication or prey detection,” said Dr Federico Degrange of the Universidad Nacional de Córdoba, CONICET and the Centro de Investigaciones en Ciencias de la Tierra, Argentina, who is the lead author of the paper published in the Journal of Vertebrate Paleontology.
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Federico J. Degrange et al. 2015. A new Mesembriornithinae (Aves, Phorusrhacidae) provides new insights into the phylogeny and sensory capabilities of terror birds. Journal of Vertebrate Paleontology, vol. 35, no. 2; doi: 10.1080/02724634.2014.912656
