"Still, from a few teeth and jaw fragments, they build up so much. Evolution is just conjecture on conjecture on conjecture. I don't have enough faith to believe in a 37 million year long chain of guesses."
That was what I thought. A few teeth and jaw fragments and they know all this from 37 million years ago? A leap of faith.
Only to the ignorant. Teeth and jaw fragments can tell a knowledgeable person a lot about the owner of that tooth or jaw fragment. Dentition can be signature features in identifying evolutionary relationships because certain dental features and certain combinations of features arise and are preserved in some lineages and not in others.
Further, by examining the surrounding structures, the combinations of teeth, their placement, etc., knowledgeable people can learn a lot about the behaviors and diet of these creatures, because certain features are consistent across lineages, depending on these dietary or behavioral factors.
Indeed. . .a 'Leap of Faith'.
Why? Because we are intelligent enough to take what we see in extant organisms and apply that consistency of morphology to fossils? Why would something that reliably applies to today's organisms not apply equally to extinct organisms?
Was there some point in the past where the morphological relationship between features and functions changed drastically? When would that have been? During some time period or event that has no physical evidence?
Or were you just barking at the moon?