0.57" (1.45 cm) Haplocanthosaurus. tooth from the Morrison Formation of Moffat County, Colorado. 149 million years old. 

Haplocanthosaurus teeth are flatter, straighter, and come to a a tip. The teeth also can have a type very round, faint denticle. These features can distinguish these teeth as Haplocanthosaurus and not Camarasaurus/Brachiosaurus.