The weapons required for the achievement (kill a dinosaur with each weapon) are:

.44 Magnum Revolver
.45 Caliber Handgun (Colt 1911)
1855 Rifle (Colt Model 1855)
30-06 Auto-Rifle (BAR)
5.56 Rifle (SCAR-L/Mk-17)
9 MM automatic handgun (Glock 18)
Black Powder Rifle (Sharpshooter)
Crossbow
Light Machinegun (M249)
Rocket Propelled Grenade
Shotgun (automatic)
Shotgun (short barrel)