While there isn't one official "Jurassic Park" expansion for GTA San Andreas , several total conversion mods create a story-driven prehistoric experience. The most prominent is the mod, which replaces the streets of Los Santos with a wild prehistoric world. The Story of "Cretaceous Runner"
: You must complete missions centered around the life of a dinosaur, such as fighting off predators and retrieving stolen eggs . gta-san-andreas-jurassic-park-mod
If you'd like to try these out, I can help you find or more details on specific dinosaur species available in these mods. While there isn't one official "Jurassic Park" expansion