Higher or Lower
Two dinosaurs, one question. Was the new one longer or shorter, heavier or lighter, earlier or later? Keep going until you get one wrong.
Your streak
The dinosaurs you met
How to play
The dinosaur on the left shows its figure: its length, its weight or when it lived. Decide whether the one on the right was longer or shorter, heavier or lighter, earlier or later. Tap your answer, or press 1 or 2.
Get it right and the right-hand dinosaur moves across to face a new one. One wrong answer ends the run. Your best streak is saved in this browser, and every dinosaur you call correctly joins your fossil card collection.
The real story
Few dinosaurs are known from a complete skeleton, so lengths and weights are estimates, worked out from the bones that survive and from close relatives. We only pair dinosaurs when the gap between them is wide, so a small difference between estimates cannot flip the answer.
Ages come from the rocks the bones were found in. Time is the biggest surprise: Stegosaurus was gone more than 70 million years before Tyrannosaurus rex appeared, a longer stretch than the one between T. rex and us.