Vestigial

[ve'stɪdʒɪəl;-dʒ(ə)l] or [vɛ'stɪdʒɪəl]

(adj.) not fully developed in mature animals; 'rudimentary wings' .

Edited by Edith--From WordNet

(a.) Of or pertaining to a vestige or remnant; like a vestige.

Edited by Carmella