Fort Union Seed Pod?

[Salvageon]

In my fossil leaf collecting in the Fort Union formation near Roundup, Mt I run across these plants quite often. They are just a stem with these round pods or fruit attached. Pictured are two examples and as you can see the pods are round and not flattened out all the time. So far I have not found any leaves attached although there are several different species in the surrounding layers. Any ideas on species would be greatly appreciated. Thanks

[jpc]

Those are very nice.

[Auspex]

This is pretty interesting to me. I have a mystery that bears a resemblance:

It's from the other side of the K-Pg boundary, but still...

Someone has to know something!

[Salvageon]

Top and left look like two bird tracks to me.

[Auspex]

Top and left look like two bird tracks to me.

Yes, Cretaceous bird tracks (which is why it is in my collection). It is the plant material that is the mystery.

[Salvageon]

That's not far for me. I'll have to explore over there some time. Great specimen.

[abyssunder]

...they are a little like those shown here http://waynesword.palomar.edu/glendive1.htm

[Plantguy]

Salvageon and Chas....Dang, those are all very nice examples. Can't offer any specific ID help but I did shoot an email off in off of garnering some help..if I hear anything back I'll update this.

EDIT: Hey gang. I already have an answer tonight...

Dr.Steven Manchester, Curator of Paleobotany,Florida Museum of Nat History took a look at the photos of the samples. He's thinking all are Equisetum rhizomes with whorls of tubers, rather than fruits. He's seen them occasionally in various Paleocene and Eocene sites.

Very cool! Thanks for showing us!

Regards, Chris

Edited May 31, 2015 by Plantguy

[Salvageon]

Thanks for all the info I'll look those up and try to find some matching pics. I'm sure I'll run into more hopefully with leaves or some identifying stuff with it. If I do I'll post more pics. Appreciate the interest,

[Diceros]

Wait, so the carbonized plants we're seeing here from the lt. Maastrichtian and lt. Paleocene of Montana are the roots of horsetails? I didn't know they even had roots. And the perpendicular knobs are root tubers, like a potato or a peanut? Are they to store food or just stabilize the upright horsetail? Sorry, non-plant person asking.

The shallow ripple marks on the Cret, slab suggest they lived in or near shallow fresh water, which was walked in by a big wading bird. You always see pictures of horsetails near shallow water. Seems like a nice place to cool off, after a long hot day.

[Auspex]

Wait, so the carbonized plants we're seeing here from the lt. Maastrichtian and lt. Paleocene of Montana are the roots of horsetails? I didn't know they even had roots. And the perpendicular knobs are root tubers, like a potato or a peanut? Are they to store food or just stabilize the upright horsetail?...

I had been given a similar but very tentative opinion a couple years ago. My problem with it is that the straight 'sticks' appear to be quite rigid; note how they are arrayed at all angles to the direction of energy (the ripples), without any deviation from being straight. Underground stems (rhizomes) are typically flexible by nature. Also, how would it happen that we would have a bunch of rhizomes ripped up, but no sign of other parts of the plant?

I need to add here that this small slab is just part of a very large one, upon which were found dinosaur tracks as well.

[piranha]

Steve Manchester is usually correct with his plant IDs. Here's the same ID from the UO paleobotany specialist:

"These are tubers on rhizomes of Equisetum, probably E. globulosum."

[Auspex]

I can not find anything associated with Equisetum that approaches the opposed-lobe morphology of these fossils...

[abyssunder]

I agree with you,Auspex.

Also, I don`t believe in the Equisetum rhizomes theory.

[Salvageon]

As soon as I can I'll try to find more specimens and will take pics of them in site if I can. Right now too many blasted thunder storms! Maybe I can sneak in between them.

[piranha]

I can not find anything associated with Equisetum that approaches the opposed-lobe morphology of these fossils...

~.jpg

Two undisputed paleobotany heavyweights agreed emphatically. I can't imagine these guys are incorrect, but as you still have doubt, you should shop it around to some more experts.

[Auspex]

Two undisputed paleobotany heavyweights agreed emphatically. I can't imagine these guys are incorrect, but as you still have doubt, you should shop it around to some more experts.

I do not dispute in any way that they said what they did, that they know what they are doing, nor that they are most probably correct

I'm just hoping for a better understanding myself.

[fiddlehead]

I might be able to clear this up. Some modern species of Equisetum, not all, produce tubers or bulbils along their rhizomes, which are generaly used to store food. They are also known to occasionally produce aerial shoots. The form in question here is generally excepted to be tubers, but they are unlike any know modern form, which appear mostly as a single inflated bulb surrounding the rhizomes. Occasionally, modern Equisetum are know to produce several bulb-like tubers of varying size in a row, and appear like small potatoes on a string. This interestingly is how forms interpreted as tubers appear in Paleozoic floras.

Hope this helps,

Jack

[Plantguy]

Hey all,

Looks like lots has happened since my last post yesterday..glad to see all the questions and additional info.

Chas, I saw your question about how it may have happened...I cant answer how your specimen came to be and would love to see it up close but as much of the time we only see fragments of plants and never the entire plant preserved intact anything seems possible in my mind....I was wondering if yours might simply be an example of just the rooting structure actually insitu and not derived from somewhere else?

Anyways, I know first hand the present day Equisetums are very tough plants and do alot to keep them self going...The ones I've seen send out these rhizomes everywhere. I've had some fun trying to eliminate them from a flower bed and just a small leftover segment seems to be able to keep the stand going. I understand this behavior with rhizomes and tubers goes way back...maybe directly attributable to having to adapt to being buried by sediment from creeks/creeks/ponds and the constant water level changes. I think the plant can regenerate from both the tuber and the rhizomes but someone else will have to confirm that.

I was hoping my species in the back yard had some tubers so I dug it up again when I got home today and nope not any at least this time...You can see the linear nature of the plant as it grows...I'm not even sure the tubers are a characteristic of this species as Jack has mentioned--but I love digging plants up and replanting them!

Here's a link to an article about a Cretaceous form with pictures of a present day E. arvense which shows tubers and some of those from the chinese fossil example.

Fossil Equisetum from the Lower Cretaceous in Jiuquan Basin, Gansu, Northwest China and its paleoclimatic significance Bai-Nian Sun, Bao-Xia Du, David K. Ferguson, Jun-Lin Chen, Yu-Li He, Yong-###### Wang, Palaeogeography, Palaeoclimatology, Palaeoecology 385 (2013) 202–212

http://www.researchgate

.net/profile/Yongdong_Wang/publication/263389261_Fossil_Equisetum_from_the_Lower_Cretaceous_in_Jiuquan_Basin_Gansu_Northwest_China_and_its_paleoclimatic_significance/links/0f31753ab81b8e1920000000.pdf

Here's also a google link listing a book

The Hell Creek Beds of the Upper Cretaceous of Montana By Barnum Brownmentioning Hell Creek Equisetum.

https://books.google.com/books?id=sXMrAAAAYAAJ&pg=PA843&lpg=PA843&dq=hell+creek+equisetum&source=bl&ots=hCCKRmWu7D&sig=9P17R3MnVjwALh9jBflEUO_znro&hl=en&sa=X&ei=-ARtVbClNYPTsAWmoIGYCQ&ved=0CEUQ6AEwCA#v=onepage&q=hell%20creek%20equisetum&f=false

With more time and research there might be some other specific Paleocene and Cretaceous writeups...

Thanks again all gang...I enjoyed seeing the fossils and learning some stuff about them...I know there is probably an unanswered question in this thread somewhere but I'm whooped and need to go to bed soon...god knows I need the beauty sleep!! bump it again as needed.

Regards, Chris

[Diceros]

Thanks for the helpful explantions, fiddlehead and plantguy - good to have fossil plant people handy!

[verydeadthings]

I'm certainly no expert on plant fossils, but I do have some Cretaceous Hell Creek Formation seeds from Montana that bear a passing resemblance to those fossils. Tentatively they have been identified as Spinifructus antiquus. Here's the link to the images and discussion: http://www.thefossilforum.com/index.php?/topic/51604-fossilized-tree-seed/#entry554602. I figured the post might be of interest even if not directly relevant to this topic. Great find!

[Salvageon]

Wow! Thanks for all the info. It will take a while to process all of it.

[Auspex]

My mind is beginning to get some traction on this; I like a good balance between the theoretical and the actual

[Diceros]

May I ask the fossil plant people a related horsetail question? I got my Masters degree in micropaleo, so I used a fine screen a lot. I'd read that horsetails had siliceous spicules embedded in their stalks (the reason herbivores don't eat them), so I cut up a few, put them in chlorox to dissolve (I apologize to you guys for the plant abuse), then screened them. Sure enough, there were the tiny clear glass-like spicules. My question is, do those horsetail spicules ever get preserved in the fossil record, in low-energy freshwater deposits? My guess it they're made of some unstable form of silica (the opposite of crystalline quartz), like amorphous opal, and might dissolve over time.

[Salvageon]

This may get a negative reaction but I've been thinking of trying to cut one of the pods in two with my tile saw. That is if I find some more. Will I be excommunicated for trying? It might answer some questions or just destroy it.