Bigfoot believers have been pointing to supposed dermal ridges as proof that bigfoot does exist. Well what is a dermal ridge? They are ridges on the skin - think finger or toe prints. If a cast does have dermal ridges, they reason that it would be too hard to fake (at least out in the middle of nowhere) and couldn't be naturally there in a random impression in the ground.
However, are the so called dermal ridges found in some bigfoot castings actually dermal ridges or are they part of the casting process?
Here are two quality links that cast a major doubt on dermal ridges found in supposed bigfoot tracks.
Michael R. Dennett's article on Matt Crowley's research and Matt Crowley's website itself.
Essentially, what happens is when you make a cast, the material is poured and what materials you use can lead to tiny ridges on the cast. It is entirely possible to make an impression of a brick or smooth cereal bowl into the ground, then make a casting and get the same sort of thing that bigfoot enthusiasts claim are dermal ridges.
This research certainly takes away from the dermal ridge claim.