Talk:Mysteries of the Past/@comment-30491881-20170202095729/@comment-26662093-20170202150614

Debateable. Blood typing was discovered in 1900, and in Welcome To Concordia Violet tells us that the breakthrough allowing scientists to categorize blood into different types is quite recent. As we're never given a concrete date, it is possible that for the sake of simplcity they're just counting 'Early 20th century' as 'Late 20th Century'.

I would personally avoid changing anything until we get confirmation one way or the other though.