← Rex's Notes
Iguanodon
A thumb spike for trouble.
Said: ig-WAH-no-don
Era: Cretaceous · 126 to 122 million years ago
Diet: Herbivore
Habitat: Mixed forests and floodplains of Europe
Size: about the length of two cars parked end to end.
What it was like
Iguanodon had a sharp pointy thumb instead of a claw. Scientists first thought the spike went on its nose, like a horn.
What we know now
The second non-avian dinosaur ever named, in 1825. Early reconstructions placed the thumb spike on the snout; the correct anatomy was sorted out after the 1878 Bernissart bonebed in Belgium yielded dozens of complete skeletons. Could walk on all fours when grazing and rear up on two when running or browsing.
Notes
- The fifth digit was prehensile, useful for grasping plants.
- Cheek teeth were similar to a modern iguana's, hence the name.
- Bernissart specimens were found 322 meters underground in a coal mine.