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Showing results for tags 'minnesota'.
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Another angle. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Turn out that is where the missing thorax is! So tightly coiled than I thought. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
This one specimen is a typical head - it is much more pointed. Then I accidently chopped a piece off and got a surprise. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
The head is bottom center - camera couldn't capture pieces of I suspects eyes or something else. Its the darker areas where parts of the very fragile shell remains. The more blunted parts are the pygidium. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
Illaenus americanus. Localized abundant in Middle Platteville formation. Localized means that one small area of a few feet may have a lot but harder to find not too far away. At first I was finding only Cephalons and pygidiums which can be more subtle difference in this species - the head is more pointed to supports its eyes. This one has 2 pygidium one adult one juvenile, plus unidentified pieces from other trilobites. -
From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
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From the album: Trilobites of Minnesota Decorah/Platteville/Galena Formation
The first three pictures are Ectenaspis beckeri. I usually don't like to work on trilobites much because of their fragility and their 3d structures plus I don't know what tools that's available to use with it. How I came to the conclusions - it have continuous solid structures which means throat are missing from this specimen. The tip is missing and maybe parts of the head as well. It have a unusually elongated head and its side spine appear to be curved. One theory I have is it is upside down. From Decorah formation. Don't know if its rare or uncommon as bottom half looks similar to others fr -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
?Oepikina minnesotensis. I'm not 100% sure yet. Oepikina tend to have very fine costae and those specimens are literally loaded with costae making them darker. There's two in the leftmost rock specimens along with a Strophomena. The annoying thing is its hard to see hinge line for a positive id. Among the most inflated brachiopod I have seen from Decorah formation, only inarticulate brachiopods are this inflated. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Sowerbyella minnesotensis. Upper Decorah formation, all of Galena Formation. Tend to be characterizing into identification of Upper Decorah formation (only exposed in Lilydale Regional Park and southern Minnesota). Other locations in Twin Cities tend to be lower (maybe middle) Decorah formation. Very abundant, can make up a big section of some shell hash. The one specimen in the middle is the largest and complete that I had found so far. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
?Cincinnetina minnesotensis. Middle Platteville Formation, rare. I hadn't found any Hesperorthis in middle Platteville yet and there's lack of information on Platteville orthid brachiopods as I have one to two other species from middle platteville but they're tiny and difficult for me to photograph at current. The big brachiopod in NE rock is Oepikina inquassa - they have very fine costae and may appear to be darker because of it. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Unlabeled inarticulate brachiopods. Common in Decorah formation and middle Platteville Formation. I had an interesting discussion with another person recently - turn out only inarticulate brachiopods tend to keep their shells - the other extreme lookalike which is non coiled limpet like Monoplacophora tend to be preserved as molds like true gastropods. -
From the album: Bryozoan of Minnesota Ordovician
Prasopora conoidea from Decorah Formation. Those are the largest ones I have found - seemly? (not 100% sure) only in upper Decorah Formation. The middle one is the largest I had found so far. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Unidentified orthids on the left. Dinorthis pectinella on the right. Very similar but seemly different? Smoother edges is one of the big differences. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Unidentified orthid for now. Strongly resembles Dalmanella sculpta but have sharp edges. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Vinlandostrophia extensa Decorah formation. Rare. I includes a specimen of Pionodema subaequata and Rhynchotrema ainslei for compare - the costae is much larger and more coarse. For a Vinlandostrophia it doesn't have wings. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
not identified yet. Two very similar genus. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Vinlandostrophia (formerly Platystrophia) trentonensis. Practically the only Minnesota Decorah formation orthid that I know of that have wings (Strophomena filitexta from a different family have wings but not as pronounced). Rare - hadn't found any 100% intact adult specimen yet as one wing always seem to be broken off. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Hesperorthis tricenaria - from Decorah formation. Seem like it have more diversity of shapes in Decorah than platteville, mostly in height. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Hesperorthis tricenaria. This is upper Platteville formation which is very abundant and the most easily identified brachiopod from that layer - diversity of fossils in upper platteville while abundant, tend to be very low in diversity. Among brachiopods of upper platteville, mainly Strophomena filitexta, Hesperorthis tricenaria, Oepikina minnesotensis, Rafinesquina sp, and maybe Oepikina inquassa is practically the only brachiopod species found in upper Platteville. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Dinorthis pectinella Tend to occurs in the same layers as Cincinnetina meedsi. Strongly costae, no inferior costae compare to Cincinnetina meedsi. Also tend to separate in halves when the brachiopod dies. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Oepikina minnesotensis. Occurs mainly in upper Platteville formation. I'm not 100% sure if they occurs in decorah formation as I had found unusual circular inflated shells but its much harder to see their hinge line or muscle scars at present. Either the decorah version is a extreme version of Doleriodes pervetus or Oepikina minnesotensis. They usually differs from Strophomena filitexta into being more compact and rounder, also more inflated. They're much smaller compare to Oepikina inquassa and less variable in shapes. You can see the fossil in the farthest left of the picture have unusual we -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Unusual Oepikina inquassa. Very rugose in texture and doesn't have any encrusting but still have fine costae thought its harder to see them in this photo. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
More variable in Oepikina inquassa shapes. Those are very strongly like garden shovel shapes. But usually tend to be heavily encrusted. -
From the album: Brachiopods of Platteville/Decorah Twin Cities Minnesota
Strophomena filitexta - very abundant in both decorah formation and platteville formation. Usually more variable in shape and get bigger in decorah formation.
