Science sleuths Hannah Fry and Adam Rutherford investigate which dinosaur is the smallest and what size can reveal about the life of extinct animals.
"What is the tiniest dinosaur?" asks younger listener Ellie Cook, aged 11.
Today's hunt takes us from the discovery of dinosaurs right up to the present day, which is being hailed as a 'golden age' for palaeontology. One new species of dinosaur is currently being unearthed on average every single week.
But what's the smallest dino? And what can size reveal about the life of extinct animals?
Hannah goes underground at the Natural History Museum to look through their vaults in search of the tiniest dinosaur with palaeontologist Susie Maidment.
Meanwhile Adam chats to dinosaur expert Steve Brusatte from Edinburgh University about why size really does matter, especially when it comes to fossils.
Presenters: Hannah Fry, Adam Rutherford
Producer: Michelle Martin.