What I would do (as GM of course) is to simply say that the beastie materialized out of thin air beside the caster snarling, frothing at the mouth and ready to pounce (the beast that is, not the caster). :wink: This is obviously more "cinematic" and exciting, although it clashes with the spell description.
I think what is meant that if the caster is in a particular environment, say the Vendhyan jungle (there used to be jungles in historical India. I know this for a fact. The word jungle itself comes from ancient Sanskrit!) then the caster may summon a beast which is plausibly of that ecosystem or environment, but not one that is from another. So a Vendhyan tiger (Hyborian version of a Bengal Tiger, perhaps) could appear, but not an Arctic polar bear, or man-eating penguin of Hyperborea! :lol:
I agree that there should be a more considerate rewrite of this spell in the future.