Dog-sized Dinosaur That Ran Around Feet Of Giants Discovered

A labrador-sized dinosaur was wrongly categorised erstwhile it was recovered and is really a caller species, scientists person discovered.

Its caller sanction is Enigmacursor - meaning puzzling runner - and it lived astir 150 cardinal years ago, moving astir nan feet of celebrated giants for illustration nan Stegosaurus.

It was primitively classified arsenic a Nanosaurus but scientists now reason it is simply a different animal.

On Thursday it will go nan first caller dinosaur to spell connected show astatine nan Natural History Museum (NHM) successful London since 2014.

BBC News went down nan scenes to spot nan dinosaur earlier it will beryllium revealed to nan public.

The find promises to shed ray connected nan evolutionary history that saw early mini dinosaurs go very ample and "bizarre" animals, according to Professor Paul Barrett, a palaeontologist astatine nan museum.

When we visit, nan designer of a typical solid show lawsuit for nan Enigmacursor is making last-minute checks.

The dinosaur's caller location is simply a pavilion successful nan museum's awesome Earth Hall. Below it is Steph nan Stegosaurus who besides lived successful nan Morrison Formation successful nan Western United States.

Enigmacursor is mini by comparison. At 64 cm gangly and 180 cm agelong it is astir nan tallness of a labrador, but pinch overmuch bigger feet and a tail that was "probably longer than nan remainder of nan dinosaur," says Professor Susanna Maidment.

"It besides had a comparatively mini head, truthful it was astir apt not nan brightest," she adds, adding that it was astir apt a teen erstwhile it died.

With nan fossilised remains of its bones successful their hands, conservators Lu Allington-Jones and Kieran Miles expertly combine nan skeleton connected to a metallic frame.

"I don't want to harm it astatine this shape earlier its revealed to everybody," says Ms Allington-Jones, caput of conservation.

"Here you tin spot nan coagulated dense hips showing you it was a fast-running dinosaur. But nan beforehand arms are overmuch smaller and disconnected nan crushed - possibly it utilized them to shovel plants successful its rima pinch hands," says Mr Miles.

It was clues successful nan bones that led scientists astatine NHM to reason nan animal was a caller species.

"When we're trying to place if thing is simply a caller species, we're looking for mini differences pinch each of nan different closely-related dinosaurs. The limb bones are really important successful this one," says Prof Maidment, holding nan correct hind limb of nan Enigmacursor.

When nan dinosaur was donated to nan depository it was named Nanosaurus, for illustration galore different mini dinosaurs named since nan 1870s.

But nan scientists suspected that categorisation was false.

To find retired more, they travelled to nan United States pinch scans of nan skeleton and elaborate photographs to spot nan original Nanosaurus that is considered nan archtype specimen.

"But it didn't person immoderate bones. It's conscionable a stone pinch immoderate impressions of bony successful it. It could beryllium immoderate number of dinosaurs," Professor Maidment said.

In contrast, nan NHM's specimen was a blase and near-to-complete skeleton pinch unsocial features including its limb bones.

Untangling this enigma astir nan names and categorisation is essential, nan palaeontologists say.

"It's perfectly foundational to our activity to understand really galore type we really have. If we've sewage that wrong, everything other falls apart," says Prof Maidment.

The scientists person now formally erased nan full class of Nanosaurus.

They judge that different mini dinosaur specimens from this play are astir apt besides chopped species.

The find should thief nan scientists understand nan diverseness of dinosaurs successful nan Late Jurassic period.

Smaller dinosaurs are "very adjacent to nan origins of nan ample groups of dinosaurs that go overmuch much salient later on," says Prof Barrett.

"Specimens for illustration this thief capable successful immoderate of those gaps successful our knowledge, showing america really those changes hap gradually complete time," he adds.

Looking astatine these early creatures helps them place "the pressures that yet led to nan improvement of their much bizarre, gigantic descendants," says Prof Barrett.

The scientists are excited to person specified a uncommon complete skeleton of a mini dinosaur.

Traditionally, large dinosaur bones person been nan biggest prize, truthful location has been little liking successful digging retired smaller fossils.

"When you're looking for those very large dinosaurs, sometimes it's easy to place nan smaller ones surviving alongside them. But now I dream group will support their eyes adjacent to nan crushed looking for these small ones," says Prof Barrett.

The findings astir Enigmacursor mollyborthwickae are published successful nan diary Royal Society Open Science.