Absence of evidence <i>is</i> evidence of absence; it just isn't proof

Source abstract

One often hears it said that "absence of evidence is not evidence of absence". For example, if you excavate some fossil sauropods and they don't have preserved feathers, that not evidence that sauropods didn't have feathers. Oh yes it is. This is an example of a mantra that's short, catchy, and wrong. Every time you see absence of evidence, you are accumulating evidence of absence.