This is Nizar Ibrahim.
He loves digging into the past.
I'm going to take you on a journey back in time.
I'm not talking about 500 years, 2000 years, no.
I'm taking you back in deep time, to a lost world
of African dinosaurs - a place that is far more bizarre
than any other ecosystem we know of.
The Sahara is a magical place - both beautiful and frightening,
peaceful and cruel, almost like a world of its own.
Today it is a sea of sand,
but a hundred million years ago this place was a huge
river system.
When I was about 25 years old, I began a fieldwork project
to collect fossils in the border region
between Morocco and Algeria.
People told me that I'm crazy.
But I think, in science, you sometimes have to be crazy.
I think you need people to push the boundaries,
I mean that's what science is about.
People thought I would never find anything significant.
Well, we found a few things.
This is the actual site where a partial skeleton
of Spinosaurus was found.
Let's see if we can find something new.
I never fully understood the concept of deep time
until I found an ancient piece of riverbed in the Sahara,
little pebbles, and a dinosaur tooth.
And all these objects were arranged
in the same direction of flow.
This scene just came to life in my mind : a dinosaur upstream,
losing a tooth, and the tooth is just rolling on the riverbed,
is carried downstream and suddenly gets stuck
in this little sand dune, in the river.
I had, in my hands, a snapshot of time,
from a time when humans were absent on our planet.