A new KIND (no two people agree on what the word “species” means) of animal is an animal with new kinds of organs, new requirements for integration of the new organs with other organs both old and new, and a new basic plan for life.
Then how are we different from the apes? For we both have two eyes, a single heart, a single liver, dual lungs, a stomach, and so on... Show me where we have difference.
For that matter, how are our organs different from a horse? Or a cat? Or a whale? Show me where we are different species based upon your insistence on different organs.
Legs which are the major limbs are certainly a new kind of organ gonig from apes to humans; so is voluntary control over breathing. You might want to find a copy of Elaine Morgan’s “Aquatic Ape” for a long list of things which are totally different between us and apes.