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Showing results for tags 'twin cities'.
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From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Flatter than A. recurvirostis and a bit bigger.-
- anazyga
- anagyga plinthii
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From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Those are the closest specimen I could find that I think is Anazyga lebanonensis. Described as longer in length than the other two Anazyga species from Decorah Formation.-
- anazyga
- anazyga lebanonensis
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From the album: Minnesota Ordovician Decorah Cephalopods
different specimen, very fragile. Side view showing the siphuncle. Uncommon in Decorah Formation Twin Cities Minnesota.-
- cephalopod
- triptoceras
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From the album: Minnesota Ordovician Decorah Cephalopods
One of the largest Triptoceras species I have found in Decorah Formation Twin Cities Minnesota. This is a very worn specimen with septae lines barely visible.-
- cephalopod
- triptoceras
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From the album: Minnesota Ordovician Decorah Cephalopods
Triptoceras planodorsatum Decorah Formation, Twin Cities, Minnesota. Very small, this is a side view showing the bend.-
- triptoceras
- cephalopod
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From the album: Minnesota Ordovician Decorah Cephalopods
Triptoceras planoconvexum appear to be medium sized compared to the other Triptoceras species from Decorah Formation in Twin Cities. Rare.-
- cephalopod
- triptoceras
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From the album: Minnesota Ordovician Decorah Cephalopods
Apparently Whitfieldoceras mumiaforme lasts into Decorah Formation from Platteville formation. This specimen has barely visible septae and is very thin. Seem to have enlargement on the left side which is constant with Whitfieldoceras and a bend along a certain portion of the shell. Ordovician, Decorah Formation, Twin Cities Minnesota. Rare.-
- cephalopod
- whitfieldoceras
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From the album: Minnesota Ordovician Decorah Cephalopods
Top view - Rare in Decorah Formation Twin Cities. Small size, the muddy limestone made it hard to tell what species it is.-
- cyrtoceras
- cephalopod
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From the album: Minnesota Ordovician Decorah Cephalopods
Poterioceras apertum found in St. Paul Decorah Shale Spring 2023. Rare from the looks of it.-
- decorah formation
- ordovician
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From the album: Bryozoan of Minnesota Ordovician
One of the longest rugosa bryozoan that i have found so far in Decorah Shale Formation. Branches subcylindrical, branching of equal thickness. Long intervals between branches. Clusters of large cells are conspicuous, The one in the northern most part of this picture might have a crinoid holdfast.-
- homotrypa
- homotrypa minnesotensis
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From the album: Bivalves of Platteville/Decorah Formation Minnesota
Whitella is an invalid genus name - all specimens once called Whitella is in Cyrtodontula. Found in Decorah shale - the largest uncommon bivalve I have ever found in Decorah Shale as of 2021. There could be others since all bivalves are listed as uncommon to rare in Decorah shale. It could be my bias but oddly enough I only find mold impressions of this one (all 3 individuals) as negative molds in limestone without any hard shale encrust in the hollows. Trying Paint to show outlines - strongly resembles modern Anadara notabilis in general shape for example - its NOT related to Anadara. I'm only picking the name Cyrtodontula compressa for now since its the only one that at least for me closely resembles the fossils in shape and sizes. Forgot to add ruler so measurements roughly from where estimated hinge line to farther part of the mold is 50 mm for the two smaller individuals and 60 mm for the larger individuals.-
- ordovician
- bivalve
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From the album: Bryozoan of Minnesota Ordovician
Batostoma species from Mifflin portion of Platteville Formation. Since there hadn't been any official researches into platteville bryozoan, I would assume this to be a early forerunner of Batostoma fertile as it looks very similar to it but on average smaller. One rock have a different species running parallel but camera couldn't get more details. -
From the album: Bryozoan of Minnesota Ordovician
Stictoporella frondifera. Very localized abundant in lower Decorah formation Minnesota, Ordovician, Twin Cities.-
- stictoporella
- stictoporella frondifera
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From the album: Bryozoan of Minnesota Ordovician
"Batostoma minnesotense" Decorah shale Twin Cities Ordovician. I couldn't tell any difference under digital microscope or by eye examination so any similar species are lumped by me under it. Very abundant in Decorah Shale. Only difference between this and Batostoma fertile is by compare of side by side specimens. Batostoma fertile have larger zoarium that is noticeable with the naked eye.-
- batostoma
- batostoma minnesotense
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From the album: Bryozoan of Minnesota Ordovician
Batostoma fragile Decorah Shale Ordovician Twin Cities Minnesota. When comparing all bryozoan fossils from Ordovician this one stands out as having the largest zoarium. (fossil terms for the pores). Its also the largest branching bryozoan I had found in terms of masses. One thing I have noticed with this is compare to "Batostoma minnesotense" It tend to be ,more lumpy and more flexible into forms, even at times mistook for Prasopora conoidea if not for its larger zoariums.-
- batostoma fertile
- batostoma
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
This is my first digital microscope picture submitted to this website. I tried it on bryozoan but couldn't see any significant differences. Part of Amphilichas cephalon close up. It was suitable because of its tiny size but was too big to get a full screen. Note the bumps on the eyes.-
- digital microscope
- trilboite
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Ceraurid hypostome. Platteville Formation (SW corner specimen) and rest are Decorah Formation. For a long time I thought it was little rolled up trilobites, that's how much the hypostome look like. Tiny .5 cm for Decorah ones and .6 cm for platteville ones. Decorah ones seem to be uncommon to common and very easily overlooked because of its tiny size. Heck I wonder how many had I overlooked over 5 years. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Amphilichas sp. cephalon. This is pretty small - .7 cm across. Platteville Formation Twin Cities Minnesota. Rare. Its cephalon is very distinct, having 5 well definite lobes.-
- trilobite
- platteville formation
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Sceptaspis lincolnensis cephalon with damage to one eye and part of head. 1.7 cm across. Platteville Formation Twin Cities. Rare at least to me.-
- sceptaspis
- sceptaspis lincolnensis
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From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Pionodema conradi. I knew I had some tiny orthid brachiopod from Middle Platteville Formation but after checking book and this website: https://2dgf.dk/xpdf/bull26-01-02-115-132.pdf Kind of weird. I think Hesperorthis concava was invalid - too similar and two very close look alike can't compete with each other. One other brachiopod mention on the list Campylorthis deflecta look too much like Strophomena species despite a website saying genus name is valid.-
- pionodema
- pionodema conradi
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From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Zygospira sp. Apparently there are a mystery with this genus when it comes to Twin Cities. I first noticed it only from Middle Platteville Formation - 100% nonexistent from upper Platteville Formation. Much more finer costae compare to Rostricellula minnesotensis and generally smaller. Belongs in Spiriferid family despite it strong resemble to Rhyconellid family. Then after a very long absent either the same species or a very similar species popped up again in upper Decorah formation and became very abundant. I suspects the reason for this seemly weird pattern is they may be much more specialized into the type of sediments that laid on the ocean floor. The middle platteville had layers of high carbonate shale mixed in, which does not exists in upper and lower Platteville formation. Then upper Decorah formation had a harder type of shale - middle and lower Decorah formation have shale that breaks into pieces very easily. Plus from my experiences with modern Florida gastropods there are two endemic species of gastropods that had very narrow ranges. One I don't have specimens of is Sanbriel Island turret snail which is endemic to southwest mainland Florida. Not found anywhere else. The other snail species, Shiny Atlantic auger, Hastula hastata is only found generally around Jupiter Island on Atlantic side. At first it may seem like the two snail species have nothing in common but I find it interesting that they occurs in a small zone in between the carbonate sediments of far southern Florida to the keys and the sandy rubble to the north.-
- zygospira
- spiriferid
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From the album: Platteville to Decorah formation Ordovician Twin Cities
Prasopora conoidea with unidentified bryozoan. You can also see rust stains. Rust stain can be very prevailing in some layers or spots on rocks. Mainly because glacial deposits tend to be very iron rich from Norrthern Minnesota and then they get dissolved in groundwater and redeposit on the fossil shell hash because they're much harder for water to pass through. Another thing to know: Prasopora strongly prefers muddy sediments and thus wont appear or rarely in carbonate rich environment. . -
From the album: Platteville to Decorah formation Ordovician Twin Cities
Some orthid brachiopods, mainly Cincinnetina and Dinorthis along with several lookalikes tend to be found only in Upper Decorah Formation. Upper Decorah tend to overlaps with Galena Formation and Richmondian formation. That's why you can find some of the same orthid brachiopod species from Minnesota to Ohio to Kentucky.-
- upper decorah formation
- minnesota
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From the album: Platteville to Decorah formation Ordovician Twin Cities
Another interesting thing about Upper Decorah Formation is numerous of unidentified Zygospira species along with orthids of different sizes. For some unknown reasons Zygospira species are largely missing from lower to middle Decorah Formation even though they're abundant in Middle Platteville as well too in Twin Cities.-
- minnesota
- twin cities
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From the album: Platteville to Decorah formation Ordovician Twin Cities
First Vinlandostrophia brachiopod find of the year! I will have to compare it to the other two species later. Hash is much more fragmentary - I call it bryozoan hash.-
- minnesota
- twin cities
- (and 3 more)