Mazon Creek Puzzler

[John K]

Our nodules are slowly opening from our trip last month. We've got a couple pieces of calamites, and a lot of jellies. This little guy appeared last night:



the nodule is about 1" long.


I haven't been able to find another example anywhere, not even in RCFossils most excellent galleries (unless I missed it...) We're thinking it's a ray/shark purse - seems overly optimistic, but it's the only thing we could come up with.
Anyone?

Edited March 7, 2014 by John K

[Auspex]

Keep freezing that one; if there's something in it, it's under the pyramid.

[RCFossils]

I would agree to keep freeze thawing. What you are seeing is not a fossil but there might be one hiding under the tent shaped hump. Happy hunting!

[jeepinthemud]

What is the "freeze thawing" method? What would I use it on, etc?

[John K]

I would agree to keep freeze thawing. What you are seeing is not a fossil but there might be one hiding under the tent shaped hump. Happy hunting!

the fossils found at Mazon Creek are found encased in siderite nodules. Cracking them with a hammer produces so-so results, often destroying the encased fossil. The best way (though painfully slow, IMHO) to get them to open is to alternetly soak, freeze, then thaw them, until they open up, usually along the fossil plane. We've been transferring plastic bags of nodules between the freezer and the sink for the past week and a half; while most of what we got are turning out to be blanks, we have got a number of really nice jelly fish, a calamites section, and a piece of carbonized branch (ginko, maybe...) and the weird tent thing above. Nothing too spectacular, but pretty cool non-the less.







I would imagine that this method would work with any substrate that you would want to ssplit, but are afraid of hammering on. Edited March 7, 2014 by John K