Questions people actually ask

Stegosaurus means “roof lizard”. Natural History Museum: Stegosaurus (Dino Directory)

You say it STEG-oh-SORE-us. Natural History Museum: Stegosaurus (Dino Directory)

The Natural History Museum dates it to the Late Jurassic, 152 to 145 million years ago. Natural History Museum: Stegosaurus (Dino Directory) · checked 27 Oct 2026 The Smithsonian’s label dates that Stegosaurus to 157 to 153 million years ago. Smithsonian NMNH virtual tour: Stegosaurus spikes vs. Ceratosaurus claws · checked 27 Oct 2026

In the Natural History Museum’s directory, its fossils come from the USA. Natural History Museum: Stegosaurus (Dino Directory) Stegosaurus fossils come from the Morrison Formation, which also holds Allosaurus, Brontosaurus and Diplodocus. Natural History Museum: Diplodocus (Dino Directory)

The Natural History Museum gives its length as 9 metres. Natural History Museum: Stegosaurus (Dino Directory) · checked 27 Oct 2026 Sophie, the Natural History Museum’s Stegosaurus, is 560 cm long and 290 cm tall, about the size of a 4x4 car. Natural History Museum press release: World’s most complete Stegosaurus goes on show, 2014 Sophie weighed about 1,600 kg in life, roughly the weight of a small rhino. Natural History Museum: Secrets of the Stegosaurus, 2014 · checked 27 Oct 2026

It probably ate ferns, cycads and other tough vegetation. Natural History Museum: A Stegosaurus brought to life With its short neck, it probably fed on plants low to the ground. Smithsonian Magazine: Meet the dinos of “Deep Time”, 2019

Eighteen plates and four spikes were found in place. A gap above the tail suggests one more plate washed away, so the full set was probably 19 plates and four spikes. Maidment, Brassey & Barrett (2015), The postcranial skeleton of an exceptionally complete individual of Stegosaurus stenops, PLOS ONE

Scientists are not exactly sure what the plates were for. Ideas include warning off predators, recognising their own kind, and controlling body temperature. Natural History Museum: Stegosaurus (Dino Directory) An AMNH curator says display, to mates or rivals, is the most likely function. American Museum of Natural History: Apex Stegosaurus fossil and “11 Questions About Stegosaurus”

Marsh’s 1891 skeleton drawing had eight tail spikes, a mash-up of several specimens. There is no evidence for any number other than four. Smithsonian Magazine: The myth of the eight-spiked Stegosaurus, 2011

The spiky tail is nicknamed the “thagomizer”, after a Far Side cartoon by Gary Larson about “the late Thag Simmons”. Smithsonian Magazine: Watch out for that thagomizer!, 2011 “Thagomizer” isn’t an official science term: palaeontologists also just say tail spikes. American Museum of Natural History: Apex Stegosaurus fossil and “11 Questions About Stegosaurus”

No dinosaur had a second brain. Smithsonian Magazine: The double dinosaur brain myth, 2012

Its head was small, and its brain was around the size of a plum, says the Natural History Museum. Natural History Museum: Stegosaurus (Dino Directory) For its small skull, though, the brain was not exceptionally small compared with other reptiles. American Museum of Natural History: Apex Stegosaurus fossil and “11 Questions About Stegosaurus”

Stegosaurus lived about 150 million years ago and T. rex about 70 million years ago, so we live closer in time to T. rex than Stegosaurus did. American Museum of Natural History: Apex Stegosaurus fossil and “11 Questions About Stegosaurus”

The Natural History Museum says Stegosaurus didn’t live in herds: probably alone or in small groups. Natural History Museum: Stegosaurus Q&A with Prof Paul Barrett A 2015 study described a Montana quarry where at least five plated stegosaurs were buried together, which possibly suggests they were social. Saitta (2015), Evidence for sexual dimorphism in the plated dinosaur Stegosaurus mjosi, PLOS ONE

There is no direct evidence of what colour Stegosaurus was. American Museum of Natural History: Apex Stegosaurus fossil and “11 Questions About Stegosaurus”

Sophie went on show at the Natural History Museum in London on 4 December 2014. Natural History Museum press release: World’s most complete Stegosaurus goes on show, 2014 Apex went on display at the American Museum of Natural History in New York on 8 December 2024, on loan for four years. Smithsonian Magazine: Apex on display in New York, 2024 · checked 27 Oct 2026 It is displayed in the death pose it was found in, in Colorado. Smithsonian Magazine: Meet the dinos of “Deep Time”, 2019