Book of Life

There is a curious analogy between paleontology and biblical archaeology.  
In archaeology, you have the ruins of Jericho that can be dug up, and they're basically unchanged: some pieces may have been carried off by scavengers, and all the soft parts have dissolved, but basically the stone has been buried in the desert for a long time, and the archaeologist digs it up and makes guesses about it.
Along with that, the cultures involved are all still alive, still driving world history. So there's another source of information about the cultures that we can get through studying living languages, living cultures, and the text that holds them together.  The text itself has undergone edits, transpositions, errors, but manages to be maintained more or less intact through a process of careful copying and fact checking. 
We can dig up the bones of dinosaurs and make guesses about them, and try to reconstruct them that way.  Or we can look at the creatures descended from them, the birds, and study what has become of bird ways of life. And then there's the text, the bible of the saurischians, their DNA: which has been modified to suit the times, edited, miscopied, but thanks to the error checking molecules still contains in it most of the information about what dinosaurs were like, if we can learn to interpret the language its written in.