Complex sentence: It has been suggested by author and orator Terence McKenna that religious reverence for the cow is a result of early humankind's association of psilocybin mushrooms with it, developing as a result of the discovery of Psilocybe cubensis in the animal's excrement.
Split into simpler sentences: It has been suggested by author and orator Terence McKenna that religious reverence for the cow is a result of early humankind's association of psilocybin mushroom with it. This association developed as a result of the discovery of the psilocybin mushroom in the animal's excrement.