LOS ANGELES, Aug. 18 (UPI) — An extinct 5-foot-tall South American bird nicknamed “terror bird” deserved the name, scientists say, for the way it attacked and killed its prey.
From the size and shape of the beak, researchers have always known Andalgalornis was a predator, but now they know exactly how the bird killed — by wielding its huge skull and hooked beak like a pick axe to chop at its prey until it died, the Los Angeles Times reported Wednesday.
The 90-pound Andalgalornis steulleti, with a skull almost twice as big as a human’s, went extinct millions of years ago, but researchers have been using CT scans and biomechanical reconstructions to deduce how the flightless predators killed.
Andalgalornis lived in northwestern Argentina about 6 million years ago, one of a species known as phorusrhacids, but popularly called “terror birds” because of their size and fearsome skull.
Modern birds have light skulls with considerable internal flexibility, Vertebrate paleontologist Lawrence Witmer of Ohio University says.
But the terror birds had heavier, much more rigid structures, “really changing the architecture of the skull,” he said. “It was more rigid than anything we had anticipated.”
Computerized simulations of the skull showed it wouldn’t withstand the stress of grasping prey and shaking it from side to side, like a dog does a rabbit, he said.
The bird probably jabbed straight down with the skull to use its beak like a pickax, repeatedly driving the bill tip into the prey.
“It was using its powerful neck like the handle of a pickax,” Witmer said. The bird could then use its beak to pull meat off the carcass.
Considering all the strengths and weaknesses of the skull, he concluded, “this is the only strategy this animal could adopt.”
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