Jurrassic Park: Chaos Island
 

Not operation genesis which was released in the last few years but a different one released in which you controlled the characters from the films and could hatch dino eggs to help you fight off hunters. It would be really cool to see it on the site if anyone's got it.

I remember playing a demo of this a while ago. It was quite fun, don't remember the name of it though.

EDIT: It might be "The Lost World", not sure though.

Jurrassic Park: Chaos Island, IIRC. Read a review of it once, years ago.

If it's chaos island, then you can buy it here:
http://www.cdaccess.com/html/quick/chaosislpr.htm

Mobygames description gives indeed the idea this is the game you are looking for:
http://www.mobygames.com/game/windows/chaos-island