Yeah I'm definately going to get Lost Prehistorica, also loving the bone crafting idea.
Next I want to remodel the Barbarian totem options from Unearthed Arcana as most of the warriors will be Barbarians, so a little variation would be nice.
Here is what I have so far:
Allosaurus - Generic Barbarian abilities.
Anklosaurus - Heavy armour and big bone club, probably gets power attack and some form of crushing blow later on.
Raptor - Wields a clawed bracer, uses Whirling Frenzy and gets Run, maybe some kind of Pounce later on.
T-Rex - Wields a big toothed axe, gets Power attack and some kind of piercing blow to represent bite.
Tricetops - Wields a horn pick, uses Berserker Frenzy, and gets Diehard feat tree and maybe some kind of charge bonus.
Please help me balance these out.