Dinosaurs & Prehistory - Dinosaurs - Dinosaur anatomy
Which dinosaur had a distinctive large thumb spike on each hand?
Correct!
The herbivorous Iguanodon is known for its unusual thumb spikes. Each hand had a large, pointed spike that may have helped defend against predators, although its exact function remains uncertain.
The spike once caused a famous mistake: early reconstructions placed it on the nose like a horn because scientists did not know where the bone belonged. Later fossils showed that it was actually a thumb.
Source: Natural History Museum
