Season 4 was divided into two parts: A Summer series of new episodes written to serve as a coda to the series, culminating in Changing Nature, a definitive finale that sees the dinosaurs witness the dawn of the ice age; and a second, Fall series consisting of older episodes that had been preempted and never allowed to run.
Season 4 was split into two parts: a summer run of new episodes that served as a conclusion to the show, culminating in "Changing Nature," a finale where dinosaurs witness the ice age's beginning; and a fall series consisting of previously unbroadcast episodes.