How so? Scientific research on many subjects dates back to the ~17th century or so, so I'm not sure how it's a tautology to say that scientific research on a particular subject didn't begin until the 20th.

Unless you mean that the "contemporary" bit is a tautology, but you just inserted that word yourself.

Just because their research didn't lead to correct conclusions doesn't mean it wasn't research

But what if it didn't use the correct methods? I think it's fair to restrict the definition of "research" to methods which are likely to lead you towards the right answer rather than the much older method of "just making shit up".