THE BIRDS THAT TOOK OVER FROM THE DINOSAURS

We tend to think that mammals took over after the fateful asteroid wiped out the dinosaurs, but for millions of years following the impact, fearsome birds ruled Earth

- PROF STEVE BRUSATTE

Tyrannosaurus, Triceratops and many colossal, long-necked and duck-billed dinosaurs were there on that fateful day 66 million years ago when a 10km-wide (six mile) asteroid crashed into the Gulf of Mexico. The impact triggered a mass extinction, wiping out 75 per cent of all species on the planet.

The only dinosaurs fortunate enough to survive this catastrophe were birds. And as Earth slowly healed, some of them evolved to fill ecological niches left behind by their dead dinosaur cousins and ancestors. Some in a spectacularly terrifying fashion.

Here is a selection of the most fearsome birds that ruled Earth after the dinosaurs were wiped out.

TERROR BIRDS

THESE GIANT PREDATORS WERE AS FEARED AS THEY WERE FUNNY-LOOKING

For tens of millions of years after the asteroid hit, South America stood alone, an island continent unconnected to the wider world. Ruling this land were enormous flightless birds that were a mix of funny and fearsome.

They had comically small arms, but ferocious claws on their feet; their heads were cartoonishly large and capped with flesh-slicing beaks. Scientists call them the phorusrhacids, but their nickname better evokes their personality: terror birds.

They were, in essence, Tyrannosaurus rex reborn: huge predators that topped the food chain. The largest terror birds, like Kelenken from Argentina, were 3m tall (almost 10ft) and weighed over 350kg (770lbs). They sprinted at breakneck speed, chasing down marsupial mammals and other prey, first subduing them with their kickboxer feet and then pummelling them into submission with their razor-sharp beaks.