Birds Are Dinosaurs — The Rest Is History
All dinosaurs split into Saurischia ("lizard-hipped") or Ornithischia ("bird-hipped"). The twist: birds evolved from the lizard-hipped side, not the bird-hipped one.
Saurischia includes the predators — T. rex, Velociraptor, Allosaurus — and the long-necked giants: Brachiosaurus, Diplodocus, Argentinosaurus. These look nothing alike but share a hip structure. Ornithischia covers the armored and horned dinosaurs — Triceratops, Stegosaurus, Ankylosaurus.
Not all were giants. Compsognathus was chicken-sized. Microraptor had four wings and could glide. Argentinosaurus weighed over 70 tons — heavier than a dozen elephants.
59 species spanning the full Mesozoic tree, from tiny feathered theropods to armored tanks.
Did you know?
- *Birds evolved from the 'lizard-hipped' dinosaurs (Saurischia), not the 'bird-hipped' ones (Ornithischia), despite the misleading names.
- *More time separates Stegosaurus from T. rex (about 80 million years) than separates T. rex from humans (about 66 million years).
- *Velociraptor was actually about the size of a turkey and had feathers — nothing like its Jurassic Park portrayal.
- *T. rex and Triceratops, often depicted battling each other, are on completely opposite sides of the dinosaur family tree.
- *Argentinosaurus may have weighed over 70 tons, making it one of the heaviest land animals ever, yet it was a plant-eater.
What is GuessKin?
GuessKin is a free daily guessing game built on real-world taxonomy. Choose from over 20 categories and try to identify the mystery dinosaur. Each guess reveals how closely related your answer is to the target through a shared classification tree.
How does it work?
Every dinosaur in GuessKin sits on a taxonomy tree — a branching hierarchy that shows how things are classified and related. When you make a guess, the game shows you the nearest common ancestor between your guess and the answer. The closer that ancestor is to the answer, the warmer you are. The tree visualization grows with each guess, narrowing down where the answer lives and helping you triangulate.
How to get the best score
- •Fewer guesses is better. The ideal game is guessing it in 1. Every guess counts against your score.
- •Speed matters too. The timer starts on your first guess. Quick, confident answers are rewarded.
- •Read the tree. Each guess gives you real taxonomic information. Pay attention to which branch the answer is on and which branches you've already ruled out.
- •Start broad, then narrow. Your first guess splits the tree. Pick something that gives you maximum information, then drill into the revealed branch.
Each GuessKin category uses a real classification system. These aren't made-up groupings — they're the same systems scientists and specialists actually use. New categories are added regularly. Every category is free, with no accounts and no ads.