dude.

thanks to NationalGeographic.com

Phorusrhacids would give even Alfred Hitchcock the shivers: Also known as terror birds, some were nearly 10 feet (3 meters) tall, weighed over half a ton (500 kilograms), and could swallow a dog in a single gulp.

A new study suggests the extinct predators may have been as fleet-footed as modern cheetahs and that some species may have kicked the bones of their prey kung-fu-style to obtain marrow.

The study is one of the first to shed light on the hunting behavior of these huge, flightless predators, which dominated South America from about 65 million to 2.5 million years ago.

"Imagine an ostrich with larger, more powerful legs and neck, armed with massive claws," said Herculano Alvarenga, a terror-bird expert at the Museu de História Natural in Sao Paolo, Brazil.