If they did not cross paths ... said the walkers left sharply defined footprints on a moist surface that was gently buried by a layer of sand soon after, before the surface had time to dry ...

Gypsum dune fields at White Sands National Monument within the Chihuahuan Desert and the Tularosa Basin near Alamogordo, New ...

Studying preserved footprints in New Mexico continues to provide insight into the first human movements in North America. A research team believes the footprints are more than 23,000 years old ...

STEVE:'Most footprints get washed away, but we were lucky. Our ancient river flooded and filled the footprint with mud and sand, protecting it. So we've got our protective layer of sand.

AB: What is the significance of finding these footprints in South Africa ... gotten stuck on a sand spit, and had to cross tidal flats and channels to get back to the mainland, where the food ...