This dog-sized dinosaur lived around 150M years ago
25 Jun 2025

A new species of dinosaur, dubbed Enigmacursor, has been identified by scientists. The name translates to "puzzling runner," and it lived around 150 million years ago.

The creature was originally misclassified as a Nanosaurus but is now recognized as a distinct species. It was about the size of a Labrador but with larger feet and longer tail.

Enigmacursor will be on display at London's Natural History Museum (NHM) from tomorrow, marking the first new dinosaur exhibit since 2014.

Enigmacursor was not very intelligent
Characteristics

Enigmacursor's head was relatively small, indicating it may not have been very intelligent.

The fossilized remains of its bones were instrumental in identifying this new species.

The discovery could provide insights into the evolutionary history that transformed early small dinosaurs into large, "bizarre" animals, said Professor Paul Barrett from the NHM.

Unique skeletal structure helped classify it as new species
Fossil analysis

The skeleton of Enigmacursor was carefully assembled on a metal frame by conservators Lu Allington-Jones and Kieran Miles.

They noted that the dinosaur had solid dense hips, indicating it was a fast runner.

However, its front arms were smaller and off the ground, possibly used for shoveling plants into its mouth.

This unique skeletal structure helped scientists at NHM conclude that this creature belonged to a new species.

Fossil originally thought to be Nanosaurus
Classification

When it was first discovered, the dinosaur was named Nanosaurus, like many other small dinosaurs since the 1870s.

However, scientists suspected this classification was incorrect.

They traveled to the US with scans of the skeleton and detailed photographs to compare it with the original Nanosaurus specimen.

The NHM's specimen was a sophisticated near-finished skeleton with unique features including its leg bones, leading to its reclassification as a new species.

Understanding diversity of dinosaurs
Diversity

The discovery of Enigmacursor mollyborthwickae provides an important insight into the diversity of dinosaurs during the Late Jurassic period.

Smaller dinosaurs like this one are "very close to the origins of large groups of dinosaurs that become much more prominent later on," said Barrett.

The skeleton's unique features and its comparison with other specimens from this era could help scientists understand how these changes occurred over time.