calc_definitive_max_rank_of_last_retained_commonality_between

calc_definitive_max_rank_of_last_retained_commonality_between(first: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen], second: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen]) → int | None

Determine latest possible generation of MRCA.

At most, how many depositions elapsed along the columns’ lines of descent before the last matching strata at the same rank between first and second?

Returns

int, optional

The number of depositions elapsed or None if no common ancestor is shared between the columns.