I was thinking it would be in the point. Somehting really narrow, like 1" wide, with a long blade (6"?). Of course, these were bio-engineered dino's, so we have metal and what not available (but obsidian
is sharper).
I definately would want to use some foot bow, or a crossbow, or catapult. No fun there!
So far, a 150#-200# bow, 2500 grain arrow, with a wicked, narrow point for penetration. Hill killed a few elephant with one shot from his 115# bow and 1700 grain arrows, getting about 30" of penetration.
Of course, there's also the idea of shooting poison arrows. You would only need a 70# bow and 700-800 grain arrows to poke a little hole to get some poison in 'em. And you could shoot them much farther away than with the clean-blade set up. But, again, not nearly so much fun
!