1. Giant crocodiles
Purassaurus lived in South America eight million years ago, and would grow up to 13 metres long. That’s more than twice as long as the largest species of crocodile alive today.
Why you’re glad they’re extinct: Being twice as big as your regular giant croc means it is also twice as absolutely terrifying.
2. Three-foot-long scorpions
Pulmonoscorpius was very similar to modern scorpions, with front claws and a sting in its tail. The difference is that it was a metre long.
Why you’re glad they’re extinct: You couldn’t pick these bad boys up by their tails and throw them out the window. But they could probably do that to you.
4. Spiders with stings like scorpions
Attercopus was the earliest known true spider, as it could produce a web. But it still had a sting like a scorpion.
Why you’re glad they’re extinct: All the bad of a spider and all the bad of a scorpion, rolled into one horrible hybrid.
Megalodon grew up to 50 feet long.
Why you’re glad they’re extinct: Their teeth were the size of an average human hand. *shudder* Despite that, many people seem to wish they were still around, and as with the Loch Ness monster, there have been many “reported sightings” in recent years.
6. Weird gigantic hybrids of scorpions and millipedes that lived in water
Jaekelopterus was 2.5 metres long, and lived in fresh water.
Why you’re glad they’re extinct: Because, as one researcher told Nature: “They would probably lie in wait. When another animal went in front of it, it would lurch forward and capture it. … These things would tear their prey to shreds and then eat the little pieces.”
8. The largest species of snake ever
Titanoboa grew up to 13 metres long and weighed over a ton. It lived in the warm climates of the tropics, 60 million years ago.
Why you’re glad they’re extinct: Because it killed its prey by squashing it like the modern boa constrictor, and there is pretty much nothing that thing couldn’t squeeze like a tube of toothpaste.
10. Big scary mash-ups of prawns and squid with more teeth
Anomalcaris had shells and tails like shrimps, but tentacles and eyes like squid, except those tentacles had teeth on them. It grew up to 60cm long – although some scientists think it could have been bigger – and lived 540 million years ago.
Why you’re glad they’re extinct: Because it was carnivorous, and might have mistaken your foot for a prehistoric woodlouse-like-thing and accidentally sucked it up with its big teethy tentacles.
11. Ginormous shelled squid
Surviving Cameroceras shell fragments suggest the creature could have been as large as nine metres long. Despite being almost blind, it was a fearsome predator, probably the largest in the ocean when it was alive, 470 million years ago.
Why you’re glad they’re extinct: Because it had massive tentacles, and we don’t need any more tentacles than strictly necessary in the world.
12. Penguins as tall as humans
Palaeeudyptes klekowskii lived 37 million years ago, and stood at around two metres tall.
Why you’re glad they’re extinct: You might think these would be great, but if you tried to hug one it would probably skewer your head with its massive beak, and that would be bad.