Theoretically any PhD can trace their lineage back as far as the beginning of the modern versions of whatever discipline it is
For instance in Neurotree, many can trace their lineages all the way back to the William James or Jean Piaget, some of the original modern psychologists.
@Buffy Nope. See this request: meta.stackexchange.com/q/367235/300001 It is tagged as "status-review" so probably the staff is considering it. For other types of flags I don't know whether it would be useful.
But as far as I recall, the OP gets notified when the question is closed (not 100% sure).
@ClarkSmith I would guess that most lineages in neurotree would not end in psychology, though. People who are neuroscience professors today got their degrees in all sorts of fields, including physics and engineering as well as other areas of biology