← Rex's Notes
Stegosaurus
Plates on top, spikes on the back.
Said: STEG-uh-SOR-us
Era: Jurassic · 155 to 145 million years ago
Diet: Herbivore
Habitat: Floodplains of what is now Colorado and Wyoming
Size: about the length of a small camper van.
What it was like
Stegosaurus had a brain the size of a lime. Its tail spikes have a real name given by paleontologists who liked dad jokes: the thagomizer.
What we know now
The plates are not solid armor; they are highly vascularized and most likely served display and thermoregulation roles, possibly flushing with color. The thagomizer term entered scientific use after a 1982 Far Side cartoon. Allosaurus tail vertebrae have been found with puncture wounds matching Stegosaurus spike geometry.
Notes
- Plates were arranged in two staggered rows, not pairs.
- Could not lift its head much above shoulder height.
- Walked on column-like back legs and shorter, bent front legs, giving it a sloped profile.