This beautiful but wordless animation shows dinosaurs living their everyday lives, and the struggle of a mother protecting her young vs. hungry predators looking for a meal. It's set in Alaska, 69 million years ago, which was in the Cretaceous period. That's toward the tail end of the dinosaurs, and they were starting to evolve into creatures better adapted to the cooling planet. At least the smartest ones did.
If you didn't catch exactly what happened, watch the video again, or skip down past the next picture for an explanation. The dinosaurs featured are Troodon, Nanuqsaurus, and Pachyrhinosaurus. This video is part of a series called Dinosauria Animated Series by David James Armsby.
The Troodon is well on its way to becoming a bird. When she becomes truly desperate to save her chick, she screeches a sound imitating the cry of an infant Pachyrhinosaurus. That draws the herd of Pachyrhinosaurus to confront the predatory Nanuqsaurus. This talent for imitation is also expressed in the first scene, when she imitates the sound of an icicle falling, and in the epilogue, when she teaches her chick how to do it.