Its strange as it seems everyone’s game is different as far as prize frequency.
My game has been super stingy on Sarcosuchus and Ostafrika for several months now and similar on my daughters game. My game has been pretty rare to get a Suchomimus but her game was raining them about a month ago, enough she was able to make a lvl 40 from having maybe 1 or 2. to start.
Her game recently has been lots of T-rex and Unay, probably enough for her to make a second lvl 40 of each at this point.
Both our games are missing some Aquatic unlocks, notably, Krono, Rhizodus and Dunkleosteus. Dunkleosteus is one of my daughters favorite prehistoric creatures and she has been wanting one on her game for a long time with no luck. Just today though, she got an offer for one in the trade harbor, it wasn’t the best trade in the world but the heart wants what the heart wants. We will speed it up in the hatchery probably tomorrow… if she can wait that long.