The place where the sun don't shine?

 The  ' Archaeology and Art ( @archaeologyart Jul 11) social media account has just published these "looks like" interpretations of some peytroglyphs: ·

Various ancient petroglyphs depicting the Sun Cross or Solar Wheel motif, found across different cultures* and geographical regions, dating from prehistoric periods to antiquity.

Examples of these symbols appear across multiple archaeological contexts, including locations such as Siberia, Italy, Ethiopia, the Indus Valley, Tibet, and North America.

Why are these a "sun" - which looks nothing like any of them - rather than being perfectly obvious anal symbols? They occur over such a wide spatial (and presumably chronological) spread because most people's rectal orifices look more or less the same. Some show an internal sphincter, others the external aspect.