Primordial World Book 1 by Baileigh Higgins

This is their world, and we are the prey.
A scientific experiment gone wrong transports large portions of the modern world millions of years into the past. Trapped in the late Cretaceous Period, the survivors have no choice but to build a life for themselves and their children. Ridley, a descendant of the original settlers, has never known anything except the primordial world and its prehistoric creatures.

Tragedy Strikes…
When her father goes missing, Ridley will do anything to find him, but sophisticated search parties cost money. Hoping to win the grand prize, she enters a grueling long-distance endurance race hosted by the city of Vancouver. Accompanied by Loki, her loyal canine companion, she faces uncharted territory, savage prehistoric beasts, and treacherous rivals in one of the most dangerous competitions known to man.

Category: Science Fiction – Post-Apocalyptic