Complex limb? Let me see an elephant tie a granny knot. Maybe with training? OK. Do a square knot.

Complex communication? Elephants have communication skills on par with a 3-4 year old human. An intensely trained dog might top 200 words. My vocabulary is an easy 50,000 words. Yours is too.

Now apply both of these challenges to a chimpanzee. I doubt one could tie a knot very well. Washoe the chimp we taught sign language had a vocabulary of only 450. Yet, I have I on good authority that a very close relative of chimpanzees have developed complex thought, complex language and advanced tool use and creation.