[Bockit]

I did a semester of 'Religious Studies' focusing primarily on non-monotheistic religions as an undergrad and when we studied the origins of religion the absolute earliest things to be considered religious was when some kind of ritual was put into the treatment of the dead.

The example of the earliest known burial on the wiki page you linked sounds like one of the specific events we studied.

"The earliest undisputed human burial dates back 90,000 years. Human skeletal remains stained with red ochre were discovered[by whom?] in the Skhul cave at Qafzeh, Israel. A variety of grave goods were present at the site, including the mandible of a wild boar in the arms of one of the skeletons."