Quote from silentstormraider »"Dinosaur spells" are only spells that have Dinosaur in their type line or have the Changeling ability, as they are all creature types at all times. So the only non-creature spells that these two cards will reduce the cost of are Nameless Inversion and Crib Swap.
So, Commune with Dinosaurs and Dinosaur Stampede will NOT have their costs reduced by Kinjalli's Caller or Otepec Huntmaster.
Hope that helps.
That id not exact, also Blades of Velis Vel, Ego Erasure and Wings of Velis Vel will get their costs reduced.