Running speeds

[Chris Geatch <cig100@unix.york.ac.uk>]

        I was wondering if fossil records show faster dinosaurs 
in more recent periods.  I'm not that well up on which period every 
dinosaur lived in but thought that the length of time they were around 
was plenty for selection pressure to act and therefore faster dinosaurs 
to evolve, (could it have been this selection pressure that made them 
smaller => faster?),

Chris Geatch,
2nd year biology undergraduate,
York university.