Traveling Through Primitive Society, the Tribe Is Going to Die

In order to commemorate ten years of friendship, Lily and her best friend (Yun Duo) made an appointment to go camping together in the wild, but they were caught in a violent storm. There was no signal on the mobile phone, the GPS failed, and the tent was blown over. The two had to find a cave, wake up and walk out of the cave. The scene in front of me is of various animals galloping past. Behind them there was a group of people wearing animal skins and chasing the animals with stones of various sizes in their hands. Is this time travel? And it's still primitive times