You should still have options for North, South, East, and West when spawning in, just like on a normal map. I spawned inches from a Spino's mouth the first time, and a Rex's mouth the second time, but the third time was the charm (still had to run for my life). Made it to level 5 without dying so far.
Edit: I suppose it is possible your PGArk was created with only 1 spawn point. That would suck.