I tackle the controversial issue of time-travel at Mysterious Universe:
"A few days ago I was interviewed on a Canadian morning radio show
about my research into so-called 'cryptids.' We’re talking about the
Chupacabra, lake-monsters, Mothman, and so on. During the course of the
interview the host – in a very lighthearted fashion – asked me if I
thought it was possible that what people are seeing might be animals
extinct in our world today, but which are time-traveling back and forth
from the periods when they were alive. Because that’s the kind of question daytime radio asks, right?
"I told the host I’m actually quite open to the idea that at least some
of our cryptids may originate in other realms, or dimensions, of
existence. Which had him momentarily stuck for words, I’m pleased to
say. But, I added, that’s very different to imagining Bigfoot has a Delorean-style time-machine
to traverse countless millennia. Even I have limits on what’s feasible
and what isn’t. Well, most of the time I do. Okay, some of the time. So,
I said it was pretty unlikely. Even though, admittedly, I have to say I
have heard a few stories broadly along those lines."
Here's the link.