The Bureau of Land Management photo. Original public domain image from Flickr https://www.rawpixel.com/image/3398196/free-photo-image-archaeology-california-cc0Free Image from public domain licenseInterior of the base of the human skull. Watercolour and pencil drawing, by J.C. Whishaw, 1852. https://www.rawpixel.com/image/13975080/image-paper-face-personFree Image from public domain license