Cant find Rigid Backbone Evolution

Rigid Backbone Evolution is not dependent on any objective. It should be available directly under the Evolution list. Have you already used it on another player? Are you checking on App or In game? Where exactly are you looking? Can you please add some screenshots so that someone from the community might point out any mistake?

i didn't apply on any player yet , and i remember i still found it few days ago , but after the update today , its gone 

Your 'My Evo' screenshot is weird. My Evo tab shows a list of evos in your case. This should not happen. Usually, My Evos tab shows InProgress evos only. Can you please refresh your App, and please check again or share a screenshot of the Evolution tab as highlighted below? 

I think cache issue , in "My Evolutions" tab actually empty , here's latest screen shoot 

When you scroll down, you will see NEXT button. See if it is available on NEXT page.
Other option is to verify it in-game.