Random Prehistoric Animal Generator

What the random prehistoric animal generator does

Tap the button and it hands you something that used to be alive: a Tyrannosaurus, a woolly mammoth, a sea scorpion the length of a person, a placoderm fish with shearing plates for teeth.

They are all filed together under one comforting word, prehistoric, as though they shared a world. They did not. The span of time this list covers is so vast that picking two of these animals at random and asking whether they ever met is almost always answered the same way: no, and not by a little. The distances involved are the single most disorienting thing about the whole subject, and they are worth feeling properly.

How to use it

1. Choose how many you want. One if you are deciding, more if you are browsing.
2. Press Generate. A fresh draw every time.
3. Press Copy to take the set with you.

The gap that breaks your sense of time

Start with the two most famous animals in this list, the two that turn up together in every toy set, on every lunchbox, facing off in every film: Stegosaurus, with the plates down its back, and Tyrannosaurus rex.

They never met. That much a lot of people know. But the size of the miss is the part that genuinely rearranges your head.

Stegosaurus lived around 150 million years ago and was gone. Tyrannosaurus did not appear until around 68 million years ago. The gap between them is about 82 million years.

Now hold that number against another one. The gap between Tyrannosaurus and you, sitting here reading this, is about 66 million years.

Read those two figures again, slowly, because the conclusion is almost impossible to accept on first contact. Tyrannosaurus rex is closer in time to you than it is to Stegosaurus. More time separates the two famous dinosaurs from each other than separates one of them from the present day.

Turn it around and it becomes vivid. To a Tyrannosaurus, a Stegosaurus was not a neighbour or a rival. It was an ancient fossil, a creature from a lost world, as remote and strange to the tyrant as the tyrant is to us. If a Tyrannosaurus had dug up a Stegosaurus skeleton, it would have been looking at deep prehistory. The two icons we imagine locked in combat are separated by a gulf longer than the entire age of mammals that followed them both.

Almost none of them ever met

Once that gap opens under you, the rest of the list rearranges, because the mistake it corrects is the deepest misconception people carry about prehistory: the idea that there was a single time called Long Ago when all of this lived at once.

There was not. Prehistory is not a room. It is a corridor hundreds of millions of years long, and these animals are scattered down the whole length of it, most of them separated from each other by spans that dwarf anything in human history.

Some of the creatures in this list predate the dinosaurs entirely. The sea scorpions and the armoured placoderm fish belong to the Palaeozoic, an age of the sea that ran and ended before the first dinosaur existed. Dimetrodon, the sail-backed animal everyone files with the dinosaurs, lived tens of millions of years before them, and was more closely related to you than to any dinosaur, a detail that quietly rewrites the toy box.

Others are so recent they nearly brushed against us. The woolly mammoth and the sabre-toothed cats were still alive when humans were painting on cave walls. Some mammoths were walking the Earth as the pyramids were being planned, tens of millions of years after the last Tyrannosaurus had turned to stone.

So a random pair from this list, say a trilobite and a mammoth, are not two versions of the same distant past. They are separated from each other by something like half a billion years, a gap so large that the trilobite is closer in time to the formation of complex life than to the mammoth. Calling them both prehistoric is technically true and profoundly misleading, like filing the invention of the wheel and the invention of the smartphone under the single heading "the past".

Where we come in

Set all of this on a single line and find the place where humans belong on it, because it is the last piece of the reordering and the most humbling.

The age of dinosaurs alone, from the first of them to the asteroid, ran for something on the order of 180 million years. That is not how long ago they lived. That is how long they lasted, a reign so long it makes the word "era" feel small.

Anatomically modern humans have been here for roughly 300,000 years.

Against 66 million years since the last Tyrannosaurus, 300,000 years is not a short time. It is a rounding error. If you compressed the whole span since the dinosaurs died into a single year, every human who has ever lived, the whole of recorded history, every civilisation, every name you have ever heard, would fit into the final day and a half. The entire prehistoric corridor stretches out behind that, and we are standing in the doorway at the very end, having arrived a moment ago.

This is what the innocuous word prehistoric is hiding. Not a single olden time, but an ocean of time, with these animals scattered across it like ships that mostly never saw each other, and our own whole story crammed into the last thin sliver of the last page.

Whatever this generator just handed you came from somewhere in that ocean. The only honest thing the word "prehistoric" tells you is that it was before us, which, given how recently we arrived, is nearly everything that has ever lived.

Where these come from

The animals are drawn from a list our team researched and checked by hand, spanning hundreds of millions of years of life, so these are real creatures rather than invented ones. Your browser picks from them at random. Nothing you do here leaves your device.

Questions people ask

Is it really true that T. rex is closer in time to us than to Stegosaurus?

Yes, and it is one of the most reliable ways to shake someone's sense of deep time. Stegosaurus was gone by around 150 million years ago; Tyrannosaurus did not appear until around 68 million years ago, an 82 million year gap. Only about 66 million years separate Tyrannosaurus from the present. By that measure the tyrant is nearer to us than to the plated dinosaur it is always pictured fighting.

Did dinosaurs and early humans ever coexist?

No, not the famous non-avian dinosaurs. They were gone around 66 million years before anything like a human appeared, so the cave-people-versus-dinosaurs image is pure fiction. The animals humans genuinely overlapped with were the recent ones, mammoths and sabre-toothed cats, long after the dinosaurs had vanished.

Why is Dimetrodon not a dinosaur?

Because it belongs to an older branch that split off well before dinosaurs existed, and that branch happens to be the one that eventually led to mammals, including us. Dimetrodon lived tens of millions of years before the first dinosaur and is more closely related to you than to a Tyrannosaurus, despite looking like something that belongs in a dinosaur set.

Are birds really dinosaurs?

By ancestry, yes. Birds descend from small feathered dinosaurs and sit inside the dinosaur family tree, which means the group did not entirely die out. In everyday speech nobody calls a sparrow a dinosaur, and that is fine, but the animal at your feeder is a genuine, living branch of the group in this list.

What is the oldest animal in a list like this?

Usually the sea creatures. Trilobites, sea scorpions and the armoured placoderm fish belong to the Palaeozoic, hundreds of millions of years ago, before dinosaurs existed at all. They are separated from the mammoths at the other end of the list by spans that make the whole age of dinosaurs look like a recent event.

References

1. On dinosaur time. Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/on-dinosaur-time-65556840/
2. When did Stegosaurus live? Time period and geological age. Extinct Atlas. https://extinctatlas.org/species-guide/when-did-stegosaurus-live/
3. Stegosaurus. Natural History Museum. https://www.nhm.ac.uk/discover/dino-directory/stegosaurus.html