Chapter Four: Teeth Everywhere

This chapter really grasped my attention when Shubin stated that teeth were a powerful window into animal's lifestyle. Once I heard this I was really intrigued as to how we know this...then I read that teeth are the hardest part of the body and are the best preserved, which is why they are the most common fossil. Shubin said that mammals use precise chewing that first came between 225 and 195 million years ago! That's still surprising even though each chapter Shubin tells us that we became what we are now because of what originated millions of years ago. This chapter was especially interesting because he talks about his first expeditions and how he was just as shocked as I was when I read that Farish's team could predict likely and unlikely places to find early mammals by simply reading scientific articles and books. I found it humorous that Shubin had to follow around Chuck in order to learn how to find fossils...and how suddenly he could find fossils everywhere just by discovering a tooth glistening in a rock. He continued to humor me when he stated his first expedition that he organized himself was disappointing until he discovered that they found a fossil that was part mammal and part reptile (with tooth on tooth occlusion), called a tritheledont back at the lab. I like how Shubin can make me laugh and enjoy learning by throwing in jokes every now and then, like when he waid he was leader only in name. When they went back to find more of the rare fossils, they ended up stumbling upon them by accident after being trapped by tides and deciding to pass the time by looking at volcanic rock (fossils preserved in the mud!). Shubin's conclusion of this chapter especially stuck with me, he said that the story of mammals is the story of processing food. He said that all animals have hydroxyapatite-containing structures (what make up teeth). He also stated that this substance was used to make the first trace of teeth (as seen with the conodont). He said that this same substance that made teeth was then used to reveal the origin of making organs (just like the armor of ostracoderm). How cool is that? My answer is....very.