To be sure, LLawavis scagliai was not large by terror bird standards, but it was still a formidable member of the Phorusrhacidae, a family that could give Alfred Hitchcock the heebie-jeebies.
Standing about four feet tall, this bird lived in Argentina during the Pliocene epoch around 3.5 million years ago. It had an enormous bone-shattering beak, and scientists think Llallawavis uttered extremely low-pitched cries when it found a tasty snack, Gizmodo reports.
Why do paleontologists think this?
To begin with, the fossil, described in the latest issue of the Journal of Vertebrate Paleontology, is the most complete terror bird skeleton discovered to date, and more than 90 percent of its fossilized bones are exquisitely preserved, Gizmodo reports.
Unearthed on a beach in 2010, it took about five years to be examined, described, and then formally named. This is because the fossil was so well-preserved, Krank.ie reports. This excellent preservation meant it was possible for the team of paleontologists who described Llallawavis to examine its voice box and inner ear in detail.
Their conclusion?
Llallawavis could only hear low frequency sounds, meaning it would most likely have a deep voice, and may have vocalized in a way that was similar to how some modern birds sound.
“A very interesting thing is that we could reconstruct the shape of the inner ear,” said Dr. Federico Degrange, who was involved in the study. “We are able to say that terror birds had low frequency sensitivity – so it seems reasonable to suggest that they also produced low-frequency sounds. Again, by comparing their anatomy with birds that are alive today, you might imagine that they sounded something like an ostrich or an emu but it’s not possible to say for sure.”
The skull bones of Llallawavis were also fused, which means it could give its enemies a good wallop when needed. This gave weight to previous research that had been conducted by Degrange in 2010. His research showed that Andalgalornis, a slightly larger relative of Llawavis, had a beak that had evolved to withstand the pressures exerted when these terror birds executed fearsome jabbing motions to attack their prey, Krank.ie reports.
While all phorhusracids were formidable predators, some became huge and were large enough to swallow a medium-sized dog whole, Herculano Alvarenga told National Geographic. One such terror bird, Brontornis burmeisteri, stood nearly 10 feet tall and weighed 1100 pounds. In some cases, their prey was likely very large as well. Glyptodonts are one possible prey item that may have been on the menu. Related to armadillos, they were heavily armored and were the size of a small car and some species were also armed with a formidable tail club. They were pretty much like a walking tank, and they definitely wouldn’t have been an easy meal.
During much of the time that these fascinating birds prowled the Earth, South America was an island continent, and as such it’s remarkable cargo of species evolved in isolation, National Geographic reports. It’s thought that when South and North America connected, North American predators like saber-toothed cats and jaguars made their way south and may have out-competed the remaining terror birds, driving them to extinction.
Fortunately, they left behind a remarkable, and beautiful fossil.
