Twice Upon A Christmas,Once Upon A Christmas Movie

Twice Upon A Christmas,Once Upon A Christmas Movie:To wind up the second annual Expedition Week, National Geographic Channel takes a look at ancient crocodiles with considerable appetites. Computer animation helps the retelling of the story from 65 million years ago, “When Crocs Ate Dinosaurs” (National Geographic Channel, 9 p.m.).

It comes between two other prehistoric investigations, “Bizarre Dinosaurs” (National Geographic, 8 p.m.) and “Baby Mammoth” (National Geographic, 10 p.m.).