With teeth, you can go really far, because in cool, dry conditions they can be preserved for tens of thousands, if not hundreds of thousands, of years. Also, yo

With teeth, you can go really far, because in cool, dry conditions they can be preserved for tens of thousands, if not hundreds of thousands, of years. Also, you only need a tiny amount of genetic material to analyse. Of course, having some genetic material is very different from having complete DNA. I guess in this case the researchers just got lucky and got the right segment after all.