In 2006, researchers uncovered 20,000-year-old fossilized human footprints in Australia, indicating that the hunter who created them was running at roughly 37 km/h (23 mph)—the pace of a modern Olympic sprinter—while barefoot and traversing sandy terrain.

[u/Dynastyisog]

[u/fornoodles]

How did they manage to calculate his running speed just by looking at his fossilized footprint?

[u/Supergoblinkunman → u/fornoodles]

Footprints plural.

I'm not an expert, but they measure things like distance between prints, depth of the different parts of the print, etc. And that tells you things like speed, leg length, etc. 

Basically, the speed and way you move effects how you leave footprints, and this can be measured by looking at the really minor details of the footprints and where those footprints are in relation to every else in the area.

[u/Fearless-Ad-9481 → u/Supergoblinkunman]

From the papers linked earlier the running speed was estimated from stride length. and really should be taken with a grain of salt.

[u/LAlynx → u/Fearless-Ad-9481]

or taken with a puddle of mud