What would actually convince you? Defining the evidence threshold for cryptid existence

Genuine question, and I'm asking as someone who's genuinely conflicted on this: what would actually constitute definitive evidence that a cryptid exists?

Because I notice people have completely different thresholds. Some want HD video and DNA samples. Others are convinced by consistent anecdotal reports spanning decades. Some trust eyewitness testimony from credible witnesses. Others think eyewitness testimony is basically worthless.

For the sake of discussion, let's use an example: what would convince you that the Loch Ness Monster (or a large unknown species in Loch Ness) exists?
- Multiple photographs over time?
- Acoustic signatures?
- Sonar data?
- Physical specimens (scales, bones)?
- Skeletal remains?
- A captured living specimen?

I ask because I think clarifying this is important. If we can't define evidence standards, we can't really have rational discussions about whether phenomena are 'real' or not. We're just talking past each other.

Physical evidence. Bones, teeth, skin samples, anything that can be independently verified and subjected to DNA analysis. Eyewitness accounts are interesting starting points, but they're not evidence - they're data that requires investigation. Photos can be faked, sonar data can be misinterpreted. DNA analysis can't be faked (easily).

I think you're setting the bar impossibly high with that requirement. Most undiscovered large species aren't 'undiscovered' because they don't exist - they're undiscovered because they're elusive, live in difficult terrain, or exist in small populations. We'd need a specimen to get DNA, but we can't get a specimen without extensive investigation first.

The threshold question is brilliant because it reveals that 'believers' and 'skeptics' are often operating from completely different epistemological frameworks. Skeptics want material evidence. Believers work with pattern recognition across multiple anecdotes. Neither approach is inherently wrong, but they're incommensurable.

Consistent, detailed eyewitness testimony from credible sources (scientists, trained observers, multiple independent witnesses) combined with circumstantial evidence (tracks, scat, habitat analysis, ecological plausibility) constitutes reasonable confidence even without physical specimens. We don't need every species to be captured to acknowledge it exists.

For me: verified skeletal remains or genetic material. Everything else is speculation. I'm not claiming creatures don't exist because we lack evidence - I'm claiming we don't have sufficient evidence yet. The absence of evidence isn't evidence of absence, but it's also not evidence of presence.