For decades people have been fascinated by creatures of the past.
What did they look like? How did they move?
Many theories have been developed for many species.
Now researchers have turned their attention to an ancient creature called Orobates.
Which lived before the dinosaurs roamed the earth.
Using cutting-edge techniques, from computer modeling to robotics,
they think they've worked out how it moved.
Orobates lived around 280 million years ago.
It was a time when vertebrates were still quite new to walking on land.
But its skeleton has been exquisitely preserved.
To work out how it might have moved
researchers scanned the fossil in three dimensions
and used this to construct a digital model of the Orobates' skeleton.
This model could then be animated
sort of like a digital marionette.
The marionette helped them work out the range of motion for each joint
telling them how far Orobates could bend or stretch.
But it's unlikely that Orobates walked
using its full range of motion in every joint
so they needed to narrow it down a bit.
One way to do that is to look at another fossil,
not of Orobates itself but of its tracks.
This fossil shows where an Orobates specimen placed its feet
long ago as it rambled across the ground.
Programming the skeleton marionette to walk inside the fossilized footsteps
narrowed down its movement further,
but there are still many options for
how an Orobates could have made the footprints.
To narrow it down more researchers turned to living animals.
The layout of Orobates' skeleton suggests it would have had a sprawling gait
like modern-day lizards or salamanders.
So researchers used x-ray video to film four such creatures.
These data helped them identify four key parameters which define sprawling movement.
These four parameters were used as the basis for a dynamic simulation
containing the skeleton marionette and the footprints.
As the weighting of these four traits is adjusted
the simulation spits out graphs containing all the possible movement
combinations which fit the bill.
Then the researchers could pick through all the outputs to find the most likely options.
But there's still a catch.
Computer simulations can't account for everything,
like the complexities of gravity.
There are so many variables that it's really hard to model them all in detail.
So researchers went one step further to validate their predictions in the real world.
They built OroBot.
This scale-sized robot was also modeled and added to the dynamic simulation.
Bringing with it more physical constraints
narrowing down the options.
And, combining all of these different approaches
they settled on an answer.
The researchers think the Orobates moved with a relatively upright gait
and had more advanced capabilities than expected for such an early land dweller.
And that hints at a different ecology.
A more mobile animal may have been more adept at picking through the landscape
and perhaps be able to travel further from water than scientists had predicted.
The researchers hope that some of their methods
could help reverse engineer the movement of other fossilized animals
and they've made their model available for free online.
Click the link in the description below to start your own investigation
into Orobates' movement