July 12, 2006

Dermal Ridges, Flexion Creases and Casting Artifacts

*Photo of a human fingerprint*


1.An object produced or shaped by human craft, especially a tool, weapon, or ornament of archaeological or historical interest.

2. Something viewed as a product of human conception or agency rather than an inherent element: "The very act of looking at a naked model was an artifact of male supremacy" (Philip Weiss).

3. A structure or feature not normally present but visible as a
result of an external agent or action, such as one seen in a microscopic specimen after fixation, or in an image produced by radiology or electrocardiography.

4. An inaccurate observation, effect, or result, especially one resulting from the technology used in scientific investigation or from experimental error: The apparent pattern in the data was an artifact of the collection method.

Dermal Ridges:

A fingerprint is an impression normally made by ink or contaminants transferred from the peaks of friction skin ridges to a relatively smooth surface such as a fingerprint card. These ridges are sometimes known as "dermal ridges" or "dermal papillae". The term fingerprint normally refers to
impressions transferred from the pad on the last joint of fingers and thumbs, though fingerprint cards also typically record portions of lower joint areas of the fingers (which are also used to effect identifications). Friction skin ridges are not unique to humans, however, and some species of primate also have friction skin ridges on "fingers" and paws in configurations sometimes similar to human friction ridge skin. Some new-world monkeys also have friction ridge skin on their tails, possibly associated with use of their tails for gripping during climbing, and the knuckle-walking great apes have friction ridge skin on the dorsal surfaces of their fingers. Friction skin ridges on humans are commonly believed to provide traction for grasping objects. In the over 100 years that fingerprints have been examined and compared, no two areas of friction ridge skin on any two fingers or palms (including between identical twins) have been found to have the same friction ridge characteristics.

Flexion Crease:

A permanent crease in the skin on the flexor aspect of a movable joint.

Over the last year or better there has been a debate going on as to whether items seen on the Onion Mountain cast are dermal ridges and flexion creases - or casting artifacts. It is my opinion, and always has been, that we must police ourselves. Matt Crowley has been doing excellent work in this respect. He has been doing work to determine the difference and if it's possible whether these items on the Onion Mountain cast are in fact casting artifacts, or as Jimmy Chilcutt says, dermal ridges and flexion creases. (Hope that made sense, lol)

I became involved in this debate last year at the TBRC 2005 Bigfoot Conference in Jefferson Texas, when a researcher asked me to look at a copy of the Onion Mountain cast. He then explained to me the debate that was ongoing at that time. I studied the cast for a while, but one thing stood out to me - and I couldnt figure it out, so I said to this researcher" Well, what I want to know is why on the heel of the cast and near the ball of the foot - Im not seeing the same "overlapping" (for lack of a better word) that I am seeing on the sides of the cast." If the side of the foot is showing this, I should be seeing it, where the thickness is the same, and I am not. Plaster of Paris I have discovered in my years of working with it - is very consistant, if you have a mistake in one spot - it will "follow through" in other areas where the conditions are the same. If this "overlapping" on the edges of the cast are a mistake by the person making the cast, we should be seeing this elsewhere too, not just on the sides. I see none at the toes, or at the ball or at the heel.

Well, he then said, "Come with me, I want you to tell this to Dr. Meldrum, and Matt Crowley" my immediate response? "NO, Im not telling these people nothing", lmao. After a few minutes of coaxing - I was talked into having these conversations.

Fast forward 7 months later - there is still no answer to my question. Matt Crowley agrees with my opinion on this, yet he has no explanation - and he cannot duplicate it either.

Matt Crowley did some early tests with Plaster of Paris, but he quickly moved on to Hydrocal and Ultracal. I have been a bit frustrated by this, as the initial test is about the Onion Mountain cast. I asked a number of people if they knew exactly what casting cement, the Onion Mountain cast was made with, and no one could say for sure, so I recently fired off an email to the man who would know - John Green, and he did, in fact, state the Onion Mountain cast was made with Plaster of Paris. It's my opinion if you are working to prove or disprove something - you should be as "true" to the original work as possible.

If you all remember, I did earlier castings using Plaster of Paris, for my very first casts I posted here on this blog. I noticed then that when the cast had finished "cooking" and I was able to measure - there was a full inch difference in the size from that of the actual track, this confused me as to why. I said nothing until recent discussions and found out that Plaster of Paris does expand with increases in temperatures and moisture content of the soil.

I never disputed that Plaster of Paris is a less than an excellent casting cement - but it does pick up detail.

The Challenge....

Matt Crowley recently challenged me to do these experiments myself and I accepted his challenge. I have no problem accepting that "artifacts" do indeed exist on casts.. He has proven that to me and what to keep my eyes open for. What I do not agree with is his assertion that because of his work regarding the "Onion Mountain cast" there is little to anything in the arguments by Jimmy Chilcutt that these are in fact dermal ridges or flexion creases. He has not proven that to me. I do not agree that simply because you have "artifacts" then all noted dermal ridges and flexion creases are "artifacts". Each noted dermal or flexion crease should be evaluated separately.

So, I took his challenge, but as stated earlier, I decided to remain true to the actual cast in dispute. I couldn't just "zip on over" to my local pottery store and pick up volcanic ash as Matt suggested, but I did purchase the next best thing - Tricalcium Phosphate or "bone ash." Bone ash has the same consistency and weight of volcanic ash. *WARNING* if you attempt this, buy appropriate face protection.. As this is some nasty stuff. I breathed in a lot of this bone ash, and this is not a pleasant experience, and it doesn't taste good either... :(

Ok, here is what I have so far. I will do future postings with more pictures and test results.

I am in no way attempting to say Matt Crowleys work is less than EXCEPTIONAL, I am simply working to show IF, in fact, dermal ridges and flexion creases can be cast using Plaster of Paris, if certain conditions create a better chance for that happening, and how that can relate back to the possibility that the items being pointed out by Jimmy Chilcutt could be exactly what Mr. Chilcutt says.

I always ask people to draw their own conclusions so these are the results I have to date.

Accepting the Challenge...

The first cast was done in dry Tricalcium Phosphate (sorry for the mistake in my earlier post) This is a dry material and has the consistency and feel of fine ash.. Breathing it is not fun. I did two castings in the Tricalcium Sulfate, one of my foot dry, and one with my foot after soaking it in water for one hour. The second test, I felt, was important because the animal we are looking for does not wear shoes or foot protection of any kind.

This is what I found.

On dry substrate dry foot track size length 9 inches, width 3 inches. No change in size noted after cast was dried. This is true to my findings of size with my first practice cast discussed earlier. I did one pour, but did not pour in the center of the cast, I simply put the casting agent in by hand, in a method similar to the splash technique as my question deals with the presence of dermal ridges and flexion creases.

*Cast one dry Tricalcium Phosphate, dry foot.

*Results -- Flexion creases and dermal ridges

*Casting Material: Plaster of Paris

As you can see, flexion creases are visible. I think this is because of the lack of pressure in the substrate- as pressing down firmly sent my foot all the way to the pan containing the Tricalcium Phosphate.

I also did not mix the Plaster of Paris thick. I instead used a thin mixture as I always do.

In a later post I will post pictures I took of my foot - in weightbearing and non weightbearing positions as I think this is important in regard to what we could be seeing on the side of the foot.

I think the ridge we see on the side of the foot is the actual spreading of tissue, skin and fatty tissue when the foot has full body weight applied, but as with all of my comments this is but one theory.

Picture 1. Arch of right foot/noted Flexion Creases

Picture 2. Heel of right foot/noted dermal ridges

to be continued....

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