Which group is superior and why?Vertebrate or Invertebrates?

Question

I have three clues:
Superior is better.
Vertebrates are with backbone.
Invertabrates are without a backbone.

Superior is:
1 : situated higher up : UPPER
2 : of higher rank, quality, or importance
3 : courageously or serenely indifferent (as to something painful or disheartening)
4 a : greater in quantity or numbers b : excellent of its kind : BETTER
5 : being a superscript
6 a of an animal structure : situated above or anterior or dorsal to another and especially a corresponding part b of a plant structure : situated above or near the top of another part: as (1) of a calyx : attached to and apparently arising from the ovary (2) of an ovary : free from the calyx or other floral envelope
7 : more comprehensive
8 : affecting or assuming an air of superiority : SUPERCILIOUS
- su·pe·ri·or·ly adverb

Answer 1

I suspect that the question is written with the answer of "vertebrates" being better because the vertebrates are generally more complex.

However, natural selection measures success by the number of individuals surviving, and invertebrates outnumber the vertebrates by a wide, wide, wide margin.

Answer 2

One might argue that since invertebrates have been around longer (by the fossil record), they have demonstrated a possibly better survival capacity as compared to the newcomer vertebrates. Some recent studies in cuttlefish (invertebrate molluscs) suggest a level of intelligence on par with a cat, and therefore exceeding most vertebrates! By criteria of survival adaptations, evolutionary fine-tuning, diversity, and behavior, invertebrates may have the edge.

Answer 3

Having a backbone does not make one species better or superior to another. The word that would make more sense is "complex." Scientists see all species as being equally well-adapted to their environmental niche.

Answer 4

You don't actually have any clues.

You need to define "better". At what?