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.
Prof Steve Brusatte holding a moa leg bone, from the Te Papa collection at the Museum of New Zealand - Image credit: Steve Brusatte
