Sauropods from the Morrison Formation of North America are a fantastic assemblage of Dinosaurs. They come in different sizes and although they may look the same, head and teeth configurations are different. A good overall comparison is Scott Hartmans skeletal drawing thunder lizard.
http://pre02.deviantart.net/b47c/th/pre/i/2015/111/6/2/thunder_lizard_size_comparison_by_scotthartman-d6909lc.jpg
Comparison of three of the more common teeth shows how different they are.
The first item