Paleontology science fair ideas?
Palaeontologists use lots of methods to investigate past life. 

Like most sciences these day, palaeontology is a growing field. More scientists are applying more methods in more sophisticated ways. The literature — what we 'know' — grows and grows. So palaeontologists use hundreds of different methods and tools today; indeed there's a whole journal dedicated to the subject!

But like a lot of other geological disciplines, it's more or less impossible to test a hypothesis rigorously, because there are no actual dinosaurs, they died out ages ago, and so we cannot know everything about them. So we have to get creative.

For example, a palaeontologist interested in how dinosaurs or early insects walked might...


Make detailed drawings of some fossils of the organism.
Use X-ray tomography to see through a specimen and look at a fossil in 3D.
Make a 3D computer model to look at how the animal might have walked.
Examine museum collections to look for evidence of a hypothesized gait, eg in field photos or in casts from actual outcrops — perhaps there's a track out there somewhere!
Look at the chromosomes of similar modern animals to determine lineages and 'shared DNA', and compare walking styles.
Build or 3D-print an actual model and see if it actually does what the scientist thinks.
Dress up like a dinosaur or dragonfly and walk around on a beach or mudflat to study the footprints. (I'm sort of but not really joking.) 


(Google around dinosaur locomotion for more!)

I realize you can't do all of this sort of thing for a science fair, but hopefully it illustrates that, when it comes to hypothesizing about the past, we have to come at problems from a few different angles, using high and low technology.

Hope this helps a bit, good luck with the project!!