Sixty six million years ago the world changed in an instant. A huge asteroid, some ten kilometers in diameter, smashed into what is now Mexico. It arrived with the force of several million nuclear bombs, and unleashed a deadly cocktail of wildfires, tsunamis, earthquakes, and volcanoes.
For years, people were perfectly happy believing that the series of fossilized footprints in Australia's Lark Quarry was all that remained of an epic dinosaur stampede. Then Science happened.
Their descendants are happy to just suck blood and pass along parasites to small mammals, but the hugeprehistoric fleas from 165 million years ago were equipped with saw-like projections around their mouth—for penetrating thick dino hides—that would probably make short work of a Chihuahua.
If you thought emperor penguins were big, this prehistoric cousin put them to shame. In its day it stood over four feet tall and was 50 per cent heavier than the already pretty massive emperor we know today.