Thunder lizards are definitely both pulp and vsf, and one of the least expensive ways to start a campaign in either genre. Buy maybe half a dozen vsf or pulp character types, and a couple of bags of dinos, and get ready to adventure in the forgotten palaces and temples of the lost world. A few bags of giant spiders, bugs and snakes won't hurt either.
It also helps that there seem to be two fairly popular sets of mold for dinos, one that works fairly well in 25mm, and a smaller set that works for 15. They work as is, though they can be made to look quite nice with a little additional shading and highlighting.