Although I don't disagree with your perspective that there could be additional senses invisible to us, I think the explanation for the size of the elephant brai

Although I don't disagree with your perspective that there could be additional senses invisible to us, I think the explanation for the size of the elephant brain is ultra-simple: "The cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements. The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity." Huge body = huge cerebellum