Note:the brontotherium patriarch in Great Divide (ring war area) will update this step (heroic encounter) Only one drops, No Trade, BUT... it has the new 'tradeable for 48 hrs...' flag on it, and everyone in the group can trade it around to get the update. DON'T DO THIS. Everyone needs the item to craft the Chipper. The Patriarch respawns almost immediately anywhere between the questgiver and the Ring War area.
Get 3 petrified treant twigs
Note:Dropped by Petrified Ancients in Forgotten Pools This IS now a group update.