Vestigial

The coccyx is a vestigial feature that shows the common ancestry of mankind and apes.

All non-winged insects have at least vestigial wings.

The coccyx is the vestigial structure of a tail.

The coccyx is a vestigial trait.

Remnants of the vascular supply of lost organs may be present in the tissues of the receptacle when all external evidence of the organs has disappeared. Only rarely does the vascular supply of a vestigial organ disappear while external remnants are still present.