Which dolphin species is the smartest? Bottlenose dolphins (Tursiops truncatus) have an absolute brain mass of 1,500–1,700 grams. This is slightly greater than that of humans (1,300–1,400 grams) and about four times that of chimpanzees (400 grams). How are dolphins the smartest animals? The Smartest Animals In The World ChimpanzeesRead More →