Question

Which is that organ which is vestigial for human but not for birds?

Answer 1

Coccyx is the vestigal organ for humans but not in animals because they have a tail.

Answer 2

Vestigial organ is an organ that has no use in the present, but suggests evolution of the species.

The human has a vestigial organ called appendix, not present in birds.

There are other vestigial organs like thymus, pineal gland and tonsils.

These are essential in suggesting human evolution has taken place.