The AI playing 'dinosaur detective'

Imagine finding a muddy footprint and trying to figure out which dinosaur made it.

It's a bit like Cinderella trying on her glass slipper... except the shoe is squishy mud, the foot weighs tons, and the owner vanished about 100 million years ago.

So where do you start?

A team of scientists have come up with a new app that helps solve the mystery by using artificial intelligence (AI).

"We try to find a foot that matches the footprint. Sometimes that is straightforward, in cases where a certain dinosaur has a highly distinctive foot. But in other cases it is really hard," said Prof Steve Brusatte from the University of Edinburgh.

Professor Steve told Newsround you very rarely find a footprint next to the fossil of the dinosaur that made it.

"The biggest problem we have is that a footprint does not perfectly match the shape of the foot. You can see this yourself next time you are walking on the beach - when you leave tracks in the sand they are not perfect impressions of your feet, and your footprints will look different if the sand is harder or softer, wetter or drier.

"So the shape of any dinosaur footprint depends not only on the shape of the dinosaur's foot, but also the type of sand or mud it was stepping into, and how its foot was moving - whether it was walking or running."

The team have turned the system into a free app called DinoTracker that allows users to upload the outline of a footprint, with the AI agreeing with human experts on which dinosaur the footprint belonged to about 90% of the time.

"The key thing is that the AI is not some all-powerful, all-knowing authority. Human palaeontologists need to look at the results of the AI and match the categories to actual dinosaur groups," explains professor Steve.

"In other words, AI won't tell us definitively with 100% confidence that a new footprint was definitely made by T. rex, but it can tell us that the shape of a new footprint is very similar to known footprints of T. rex."

The AI system also noticed that a set of footprints from the Triassic-era of dinosaurs are remarkably birdlike despite being about 60 million years older than the oldest-known bird skeletons.

Does that mean birds existed much earlier than we thought?

"We're really excited about this. Birds evolved from dinosaurs, and the oldest birds lived about 150 million years ago, in the Jurassic period. Or so we thought," explains professor Steve.

"What the AI tells us is that, yes, the shapes of these prints really truly are very similar in shape to those of modern birds," explained professor Steve.

"It doesn't mean that these tracks were definitely made by birds. Maybe they were made by dinosaurs with very bird-like feet.

"Modern birds and many extinct dinosaurs made very similar footprints, and this is yet more evidence that today's birds evolved from dinosaurs. And it is really visual, in-your-face evidence.

"When you look at the footprint of a T. rex, with its three big toes splayed out, it really looks like an oversized version of a swan or pigeon track."