The study of dinosaur vocalization began after the discovery in August 1995 of a rare Parasaurolophus skull fossil measuring about 4.5 feet long." Note: I listened to the sound on a YouTube clip as their sound files did not open on my system.
This line was released on June 1998, shortly after TLW Series 2 came out in stores. The premise was that mad scientists merged various dino DNA resulting in "Genetically Mutated Dinos Gone Bad". Features some repainted dinosaurs/humans/vehicles along with some new sculpts.