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Cretaceous Leaf? Another Mystery...

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Roadrunner

Good luck!

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paleoflor

I would agree with the "cone" hypothesis. My objection against the "crinoid" option is the six-fold symmetry of the unidentified specimen. If it were any echinodermata, one would expect to see a five-fold symmetry. Even for crinoid species with many arms (only the earliest, most primitive crinoids had five) I would expect to see multiples of five. For example, the proposed genus Saccocoma has ten arms.

post-2676-0-74052600-1404855777_thumb.jpgpost-2676-0-23529100-1404855778_thumb.jpg

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Roadrunner

I would agree with the "cone" hypothesis. My objection against the "crinoid" option is the six-fold symmetry of the unidentified specimen. If it were any echinodermata, one would expect to see a five-fold symmetry. Even for crinoid species with many arms (only the earliest, most primitive crinoids had five) I would expect to see multiples of five. For example, the proposed genus Saccocoma has ten arms.

attachicon.gifcone.jpgattachicon.gifech.jpg

I agree it may not be a crinoid - however, if you look closely it starts with a pentagon.

Saccocoma: Jurassic of Europe, and Possibly North Africa and North America

This is a minute stemless crinoid, with a bud-shaped calyx, 5 small basals and a minute central plate (a central pentagonal calyx plate which occurs inside the basal circlet).....

http://books.google.com/books?id=7kPwZ2LeSAoC&pg=PA178&lpg=PA178&dq=saccocoma+crinoid&source=bl&ots=WZUv11JGOg&sig=_qZ-xvQTi1Xnn5ogJKRJbMzoDLw&hl=en&sa=X&ei=7qm8U4D6D8ebyATZo4GICw&ved=0CEwQ6AEwCQ#v=onepage&q=saccocoma%20crinoid&f=false

I'm glad that a better explanation has been found. It is important to identify what we find as much as possible, and the person holding it has the best view of it. :)

Edited by Roadrunner

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Wrangellian

So plant material in Drumheller can preserve as a whitish material rather than coal black?

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Roadrunner

So plant material in Drumheller can preserve as a whitish material rather than coal black?

I'd either have ask a geologist or research Drumheller material more. However, it is iron oxide (the reddish material) that is being pulled out by the organic matter. Does the black Drumheller material have iron oxide that can be seen? The original post material wasn't coal black originally, was it? The matrix in the OP at least looks identical to some materials found in our area.

I have some errands to run, but if you are interested I will take one of my samples later today and try to break it in such a way that demonstrates that the redaction isn't superficial and has spread out from very little organic material in the center of the reduction. And often the reduction is very symmetrical surrounding the organic material, but not always. I have a perfect example I broke in exactly the right place at work demonstrating a sphere from what looks to be only superficial from a tiny dot in the middle. However, I can't access that right now. Anyway, I should probably have one at home too.

Edited by Roadrunner

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piranha

Here is the evaluation from a paleobotany specialist who has conducted extensive research in the Cretaceous of Drumheller.

Your specimen is, indeed, a conifer seed cone. Those are relatively common in the ironstone concretions at Drumheller, and ones like yours are assignable to the Cupressaceae. They are described in Rudy Serbet's doctoral dissertation (Serbet, R. 1997. Morphologically and anatomically preserved fossil plants from Alberta, Canada: A flora that supported the dinosaur fauna during the Upper Cretaceous (Maastrichtian). Ph.D. Dissertation. Ohio University.)

A quick glance at your specimen suggests that it is the seed cone of Drumhellera kurmanniae Serbet and Stockey, which is similar to living Sequoia and Sequoiadendron. The cone is exposed in cross section and the specimen shows a cone axis from which bract / scale complexes are radiating (lighter colored objects). I can't identify resin canals in your photos, but that cone should have them.

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Roadrunner

Here is the evaluation from a paleobotany specialist who has conducted extensive research in the Cretaceous of Drumheller.

Auspex was right - yet again! (I could have guessed that). :)

Are you still interested in pictures of iron oxide reduction in red sandstone?

BTW, I don't know why I kept typing "redaction," as it is "reduction" spots.

Edited by Roadrunner

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jpc

I have seen my share of these in Cretaceous, Paleocene and Eocene rocks of this area... it is indeed a section through a Metasequoia cone. While I have never actually prepped one out of the rocks we find them in, I have seen them free standing in 3D and it fits. They are a common enough fossil in Drumheller where the thing was found.

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Jace

Its not a Pyrite growth??? i've seen others that look like this...

Edited by Jace

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MarcusFossils

Auspex was right - yet again! (I could have guessed that). :)

Are you still interested in pictures of iron oxide reduction in red sandstone?

BTW, I don't know why I kept typing "redaction," as it is "reduction" spots.

Sure thing! I'de love any additional information! Thanks.

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MarcusFossils

I have seen my share of these in Cretaceous, Paleocene and Eocene rocks of this area... it is indeed a section through a Metasequoia cone. While I have never actually prepped one out of the rocks we find them in, I have seen them free standing in 3D and it fits. They are a common enough fossil in Drumheller where the thing was found.

Piranha's expert: "Your specimen is, indeed, a conifer seed cone. Those are relatively common in the ironstone concretions at Drumheller, and ones like yours are assignable to the Cupressaceae. A quick glance at your specimen suggests that it is the seed cone of Drumhellera kurmanniae Serbet and Stockey, which is similar to living Sequoia and Sequoiadendron."

So which one is it then?

Edited by MarcusFossils

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Auspex
...So which one is it then?

Keeping in mind that everyone who has weighed in has done so on the basis of the photograph of a cross section, displayed on a computer screen. If it is even possible to confidently assign this specimen to a species, it would take careful comparative in-hand study to do so with confidence. Remember that it took a while just to get to "cone" :) .

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PRK

I have found, that it is usually difficult to assign a special name , even when "in hand". So I'm satisfied with a genus ID. And that goes for most all fossils I find, or see

Edited by PRK

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piranha

Piranha's expert: "Your specimen is, indeed, a conifer seed cone. Those are relatively common in the ironstone concretions at Drumheller, and ones like yours are assignable to the Cupressaceae. A quick glance at your specimen suggests that it is the seed cone of Drumhellera kurmanniae Serbet and Stockey, which is similar to living Sequoia and Sequoiadendron."

So which one is it then?

Without even knowing the locality, a second paleobotanist specializing in this material has independently concurred on Drumhellera. That's how I'd label it!

Probably: Drumhellera. Is it from southern Alberta?

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jpc

Even though I have seen a few of these, I cannot say that I am up to date on the taxonomy. So I remain conservative (which is unnatural for me :) ) and call them Metasequoia.

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