Students will like researching all the periods in the Phanerozoic Era, finding the length of each period, and animals/organisms that lived during each period.
Once they have researched and filled in the table on the worksheet they can then make a time line. I encourage them to use a large poster board or even 2 taped together so that it can be a long timeline and they make great posters for the classroom to show off.
It works best to have students in groups. You can allow students to do this during class or just make it a home-project.