David Powers
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There is a strata that contains productids. It rest on a bed of mixed bryozoans. The shale is about 15 feet thick. It rest on a breccia limestone Bed. The breccia is evaporate crusts that were pilled by tidal activity.
In these shale I found part of a plant fossil. I am hoping to find more. So far I have not seen any fish. There are clams and crinoid bits.
Thank you, the specimen above was pure luck.
Cheers
David
Hi James,
Your formation is older. It would be equivalent to the Lodgepole formation which is part of the Madison group in Montana. I also have some Productids from that formation too.
The examples of Echinoconchus I saw were from Kansas coming from Penn age rocks.
The productids in the original post are from the Kibbey formation which is Chesterian late Mississippian.
All of the brachiopods on the plate are produtids. They can grow to a large size. The bachial valve on the younger ones start out flat but then become convex. I have only seen spines on the pedicle vales, never seen the bachial valve. These guys are very fragile. It is likely they are Echinoconchus. I tend to be conservative on identifying brachiopods.
I have a two more plates I am working on now. I collected them yesterday.
Hi James,
Thank you for your inqury. Based on some research the productida Echinoconchus sp are younger and found in a different region. The examples of Echinoconchus sp lack or do not show signs of spines.
Where as my specimens have spines projecting off the pedicle valve and pedicle opening. These spines are long. I have seen these spines extend a few inches into the matrix. The pedicle valves are very wrinkled. These productida are found in western edge of the late Mississippian age silty shale which are part of the Big Snowy Group. These rocks were once part of the edge of a large sea or tidal lagoon.
If you right click the posted image to view photo, you can them view the image in magnification to see spines and valve details. The photo shows both valves of this type of productida.
The differences in my leaves to those in the paper bugged me. So I contacted Dan Peppe PhD the co author of the paper you referenced. Believing he would have more insight and information for IDing these leaves. I am happy to say he answered my email. He sent me a Paper
REPRODUCTIVE AND VEGETATIVE ORGANS OF BROWNIEA GEN. N. (NYSSACEAE)
FROM THE PALEOCENE OF NORTH AMERICA
Steven R. Manchester1 and Leo J. Hickey
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, U.S.A.; and
Peabody Museum of Natural History, Yale University, New Haven, Connecticut 06520, U.S.A.https://www.researchgate.net/publication/249158109
These fossil leaves more closely match the Browniea Gen .
Between your help and Peppe’s these leaves are now identified.
Thank you
David C Powers
Hey @mackenzie-smith, thank you for the reply. I had looked at Dicotylophyllum hansonium from Peppe and Hickey 2014. At first I thought my specimens matched until I brought the photo in the report to a 100 res. and notice some differences between the example and mine. This is the best match considering leafs of a tree can be different in shape up to maturity and where they are on the tree.
I have other plates containing these an other leave. How know maybe I will find better specimens.
Thank you for your help.
Cheers
David
@mackenzie-smith I am seeking help identifying these leaves. They are from the Tullock Member of the Fort Union Formation. Site is northern edge of Miles City, Montana. I have gone to Rsearcher Gate and found a number of papers but none have images of these leaves. The leaves in the larger plate are about 3 x 7 cm. Secondary viens stater at base as palmate and the alternate along main vein. Secondary veins divide near margin . Toothe is serrate Mixed in with these leaves are Sequoia leaves and bark and grass or maybe pine needles. Rock is a clay shale.
Hi Jim Chandler,
Yes, I am familiar with the woostergeologist blog and I have read the post on the permian productid brachiopods collected from Texas. Those he writes about are a little younger. With brachiopods knowing the age of the formation where they were collected is really important. But there are a huge variety of brachiopods forming a confusing hay stack of almost look a likes. Ages and locations narrow the possibilities.
Thank for you advice.
David.
Hi McKenzie Smith,
Thank you for helping with this fossil. Yes, I noticed the lateral shoots. Because of their presence, it had to be a stem or root. I was a bit surprized to see the impression with marine fossils. At least the field of possible plants is narrowed. If there were leaves ID would be easier. Maybe next summer, I will find another with more elements to aid in identification.
Cheers
David C Powers
The fossils in question are casts. They are composed of a fine grain umber brown material that is different than the molds. The molds are fine gray sand and clay. The casts are somewhat fragile. No apparent shell. They are long with round terminations. No suturing. A slight low ridge runs the length of each fossil. Eash fossil is about 2 1/2 to 3 inches long about 5/8 wide and about a 1/8 inch thick. These do not match the baculites I found in the accompanying shale. The baculites usually have a hard gray cast material with fine sutures. The closest possibility is belemnites but the shape seems wrong to me.
These are not bones. They lack the hallmarks of bones.
The area is marine late Cretaceous.
Hi Jack Kallmeyer,
Thank you for the lead. I’m looking Archimedes now. It looks like a good match to the mesh and some other elements on this block.
Cheers
David
Hi Asa Kaplan,
Thanks for the link to the PDF. I saw that article before. I didn’t save the article for future use. I wasn’t sure the age of the limestone. I found this article “Type Sections of the
Madison Group (Mississippian)
and its Subdivisions in Montana
GEOLOGICAL SURVEY PROFESSIONAL PAPER 842”
This article identifies the area to the mile where I found the brachiopod. I will now use the linked article you’ve given to narrow the species. I will be looking at the ones you named to see how they line up with what I have.Cheers
David
