Ok I’m gonna go nuts if I don’t say this, but this is super obviously not a footprint! Has no one here ever made fake baby footprints with the side of their hand before? Look, you can see the creases from the curl of the fist, and toes aren’t even really toe shaped. Actual feet have a completely different set of creases. Plus, I can’t find a single reliable source for this image or information. If you google it, you’ll get a ton of tumblr, Facebook, and Reddit results and not a single museum or anthropologist. Now, I can’t speak to when this is from, maybe people were making fake handprint feet in Roman times, but I sincerely doubt that that’s the part of the post that’s accurate.
Anyway, if you want to make your own baby footprints, curl your hand into a fist and then look at the side of your fist that your pinky finger is on. See how the creases there match the ones in the photo? Now I know that side of your hand up and press it to your paper. That’s the “sole” of the “foot”. Now ink all your fingertips, and use each one to make a corresponding toe print. That’s it, you’ve got a foot shape. I’ll make one right now to show what it looks like, because why not.