This image is a faithful reproduction of a two-dimensional work of art and thus not copyrightable in itself in the U.S. as per Bridgeman Art Library v. Corel Corp.; the same is also true in many other countries, including the European Union. The original two-dimensional work shown in this image is free content because:
This Image (or other media file) is in the public domain because its copyright has expired. This applies to the United States, where Works published prior to 1923 are copyright protected for a maximum of 75 years. See Circular 1 "COPYRIGHT BASICS" PDF from the U.S. Copyright Office. Works published before 1923, (in this case aprox. 13,000 to 15,000 bce) are now in the public domain.
This image is also in the public domain in countries that figure copyright from the date of death of the artist (post mortem auctoris), in this case aprox. 13,000 to 15,000 bce, and that most commonly runs for a period of 50 to 70 years from the last day of that year.
This from the photographer:
I (HTO), the copyright holder of this work, hereby release it into the public domain. This applies worldwide.
In case this is not legally possible: I (HTO) grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.