lots of animals mourn their dead, even ritualistically. humans aren’t special in that way. not to mention that, even among humans, burying the dead is not the only practice. many cultures practice marine burials (dumping the corpse in a body of water), or, more popularly, cremation. many carry out these manners of disposal with no ritual at all.

Grief and mourning don’t necessitate a burial. other manners of corpse disposal can allow those who remain to process grief, and some can even provide a location for family and friends to visit in memorium.