In the passage, it had three points proving that there re no bees living 200 million years ago, on Earth. The first point is that there were no fossils of bees from 200 million years ago, and the earliest is 100 million years ago. In the lecture, the student attacked by saying that since bees do not have bones, their fossils could only be made by the liquid of a certain tree, and that type of tree might not be on Earth 200 million years ago. So, the fact that there are no fossils of bees do not mean that bees do not exist, it could be that the material used to make fossils didn't exist. Then, the second point of the text is that there are no flowers on the planet 200 million years ago, so bees could not exist because back then there are no pollen, so they don't have food.