Were Neanderthals Religious?

The 21st century has witnessed a plethora of archaeological findings and the development of means for recovering analyzable DNA from fossils. Together, these discoveries have disclosed three new species in our genus, Homo, and compelling evidence that our ancestors interbred with one of them, viz., Homo denisova, as well as with Neanderthals (Homo neanderthalensis). This raises the question of whether the species with whom our ancestors were so intimate and who, at least in the case of Neanderthals, buried some of their dead, might plausibly be supposed to have had proto-religious proclivities. That query brings to mind long-standing questions about how religions and religiosity are usefully characterized in the first place.