The Natural History Museum has admitted one of its dinosaurs was incorrectly labelled after a 10-year-old boy spotted the error.
Dinosaur fan Charlie, from Essex, has Asperger syndrome and noticed an incorrect sign about Oviraptors.
Although his parents doubted the museum had made a mistake, Charlie insisted the picture showed a different species.
The museum said it was impressed with Charlie's knowledge and it would correct the sign.
Charlie's parents had taken him and his brother to stay overnight at the London museum on 21 July.
While other children were on a dinosaur hunt, Charlie, from Canvey Island, preferred "reading the signs about them".
On one labelled Oviraptor - a dinosaur with a beak that walked on its hind legs - there was instead the outline of a four-legged Protoceratops.
Charlie knows his dinosaurs, his mother Jade said.
"He's loved palaeontology since he was very young and started reading encyclopaedias when he was about three.
"Charlie has Asperger syndrome and as part of that, when he likes a subject he will try and find out everything about it."
Charlie explained: "I found a side-by-side comparison to the dinosaur, and I saw it said Oviraptor, but then the shape of the dinosaur was wrong and we told a member of staff."
His mother said: "When he told us, we said, 'OK, we know you're good, but this is the Natural History Museum.
"It turned out Charlie was right."
A spokesman said the dinosaur gallery had been "refurbished several times" and "an error has been made".
The museum was "very impressed with Charlie's knowledge" and the sign will be corrected, he added.