i always thought a neat way for them to end the series would be:
Dinosaurs are set loose on the world. They have become too dangerous and need to be stopped before they end us, but animal rights activists don't want to kill them so we have to come up with a way to dispose of them humanely. Time travel. They round up all the dinos and take them back in time to when the dinos actually lived. When they get there, they see no signs of living dinosaurs, or dinosaurs at all. Turns out, we created dinosaurs from fossils we found of dinosaurs that were there because we went back in time to drop off the dinosaurs.
Dinosaurs are set loose on the world. They have become too dangerous and need to be stopped before they end us, but animal rights activists don't want to kill them so we have to come up with a way to dispose of them humanely. Time travel. They round up all the dinos and take them back in time to when the dinos actually lived. When they get there, they see no signs of living dinosaurs, or dinosaurs at all. Turns out, we created dinosaurs from fossils we found of dinosaurs that were there because we went back in time to drop off the dinosaurs.