False equivalence. Dolphins have exhibited general problem-solving skills in a myriad of situations, and thus qualify as a general intelligence.
BTW I tried to get Chat-GPT to solve a problem chimpanzees have been observed being able to solve (using an inverted bowl to stand on in order to reach some bananas):
"I'm sorry, but it is not biologically plausible for a chimpanzee to use a bowl of water to access bananas on a tree"