How do you distinguish different vertebrae? What are the characteristics of sea creatures vs land animals? Then when a land animal what are the distinguishing features between them? Are there specific things to look at or for when trying to ID them? What is the characteristics you look for when figuring whale or mastodon/mammoth? What are the specific characteristics you look for when differentiating deer, horse, sloth, bison? And so on... thank you so much for the input here