I built a little track wave of mud, and then I offered the bears either applesauce or maple syrup to have them walk across this mud, and then looked at their footprints.

So it took casts of those and skin, I mean, looked at how they walk and what do they do when they do that?

It's adorable.

This is Origin Stories, the Leaky Foundation podcast.

I'm Meredith Johnson, and the person bribing baby bears is Dr. Ellison McNutt.

She's a biological anthropologist and comparative anatomist at the Ohio University Heritage

College of Osteopathic Medicine. Our story today is about

why she was coaxing those bears to walk through mud, and how Ellie and her colleagues

solved a decades-old mystery about one of the most fascinating discoveries in the history of

science, the Lytoli footprints.

These are fossilized footprints discovered in the 1970s by Mary Leakey at a site called Lytoli in Tanzania in East Africa.

There are thousands of prints at Lytoli, left behind by creatures ranging from millipedes to elephants.

And among them, there are three trackways of prints that are different.

The really famous ones made up of 54 footprints that were clearly human-like.

That one's called trackway G.

There's trackway S found more recently. And then there's Trackway A,

five strange prints that scientists didn't know what to make of when they were first discovered.

Those prints were all but forgotten until Ellie came along to uncover the secret story

that was hidden in the mud of Lytoli for more than 3 million years.

Hands down, Laitoli is one of the most important paleoanthropological discoveries ever made.

And the idea that there could be 3.66 million-year-old prince that just managed to survive for that long is really amazing.

I think that they capture folks in a way that almost nothing else does in the fossil record.

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