If you want a more ready-made solution, the microworld games have a range of dino riders that work well:
http://www.microworldgames.com/collecti ... zardriders the MWG lizardmen range coming out in the new year might also be relevant.
and that can be supplemented with beasties from DRM
http://www.darkrealmminiatures.co.uk/st ... .php?cat=7and EW bounty hunters
http://www.exoduswars.com/Guild-Mounted ... rchSize=12Just a note though, the GW exodites are very chunky – the GW raptor rider mini is longer than a land raider and towers over the similar riders from EW or MWG riders. I think the MWG t-rex is a bit bigger than the GW carnosaur, or at least is a fair bit meatier. The GW triceratops dwarfs allo/anky/tri assault units from MWG and would give an imperial SHT a run for its money in a game of chicken.