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The tiniest with the longest name
Micropachycephalosaurus is an Ornithischian dinosaur that lived in China during the late Cretaceous, between 70 - 68 million years ago. Its name means a "small, thick-headed lizard". Although it has the longest name of any other dinosaur to date, it is the smallest dinosaur (0.5 to 1 meter long).
It was discovered by Dong Zhiming in 1978 and it was originally described as a member of the Pachycephalosauria, a group of bipedal dome-headed herbivores. A recent study showed that Micropachycephalosaurus is a basal member of the Ceratopsia, but this issue is still unresolved.