The image below shows another kind of foraminifera
called Pulleniatina. Unlike other microfossils, Pulleniatina
is not found on both sides of the isthmus through time.
In the graphic below, youll determine which layers
have Pulleniatina fossils.
! Click the red dots on the map to see cross sections
of cores from the Caribbean and Pacific drilling sites.
Move your cursor over the layers of each core to see
assemblages of microfossils present in the layers of
different ages. Look for Pulleniatina in each assemblage.