An emotionally-detached Forest Ranger rescues a traumatized boy from an abandoned logging site and must fight for survival against prehistoric creatures that were awakened during deforestation.

It is really good. It plants a nice seed in my head and I already see images flourishing.

I suggest that the main event is the appearance of the prehistoric creatures:

"When a deforestation wakes a pack of prehistoric carnivours, an emotionally-detached Forest Ranger must fight for survival while protecting a boy he has rescued."

The gist of the story is clear. I wonder though why an "emotionally-detached" forest ranger would risk anything to save a traumatized boy he does not know? What wakes his father instincts? You might strengthen the logline by making the boy the ranger's nephew rather than a stranger.

Also, why is the boy at a logging site? Logging sites are places where men work. Would a camp site do as well?

E.g.,

When a ranger comes across a ravaged camp site and find his young nephew is the only survivor, he must save them both from prehistoric creatures awakened by nearby loggers.

Just some food for thought...