Overview

• Enigmacursor mollyborthwickae is a dog-sized, two-legged herbivore that lived 145–150 million years ago and is known from a nearly complete skeleton.
• Discovered in the Morrison Formation between 2021 and 2022, the specimen was originally misclassified as a Nanosaurus before Natural History Museum palaeontologists confirmed it as a new species in June 2025.
• Its large feet, elongated hind limbs and unfused vertebrae indicate the dinosaur was a swift, juvenile runner navigating Late Jurassic floodplains.
• The reconstructed skeleton will go on public display in the museum’s Earth Hall from June 26, positioned alongside iconic contemporaries such as Sophie the Stegosaurus.
• Researchers say the find challenges historical assumptions and could prompt re-examination of numerous small dinosaur remains long attributed to the poorly understood Nanosaurus.