i do not want to seem too much of a nitpicky spoilsport and but if the accidental death of a butterfly by a time traveler cause such an enormous change in the timeline and how could that be since the butterfly would have be incinerate by the pyroclastic blast of the erupt volcano anyway . and and how could time traveler keep go back to the same moment and not keep meet up with their prior and late self who be also at those same few minute in the timeline . it seem there would have be quite a large crowd standing in front of that dinosaur charge . while i can accept the idea of a time wave and i seriously doubt the wave would have cause only a few change . a the wave pass and all change that would have happen and would have happen at once during the passage of that wave . so and scratch the idea of the city start to become overgrown with jungle . and why jungle at all . the location of the city would have still be at the latitude and longitude it be before and would have have vegetation appropriate to it geographic place on earth . and an endless list of other illogical inanity . bwahahaha . this flick be a weird combination of some fairly decent production value and totally ridiculous plot hole and factual error . too bad . a terrific story idea that be botch up with silly science . sigh . why and why and why and why . why spend all that money on production and not even bother to proofread the screenplay to see if it make some sort of actual sense .