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Posts treating: "shell"

Wednesday, 29 June 2016

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Wooster Alumni in Iceland 

Wooster Geologists [2016-06-29 14:21:09]  recommend  recommend this post  (182 visits) info

 US,IS
Hafnarfjörður, Iceland – Guest Blogger Ben Kumpf (’18) There is never a dull moment in the life of a Wooster geologist. This afternoon at the Lava Hostel, Keck students were surprised with a visit from Brian S. Carl, Wooster alumni class of ’87. Brian, now a Senior Production Geologist for Shell, stopped by after hearing word

Peilinia quadriplicata pelecypod from Texas 

Views of the Mahantango [2016-05-22 09:01:00]  recommend  recommend this post  (177 visits) info

 Cretaceous; US
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Another pretty cool looking oyster that I found in the Texas creek I was exploring is Peilinia quadriplicata (also called Ostrea quadriplicata). This species is very easy to ID based on the look of the shell. I only found a left valve but it has the typical splayed look to it, kind of like a duck foot. While the shell started out with a relatively smooth margin, as the animal grew older it started to have some distinct "points" with flat, straight areas of margin between them. Overall the shell [...]

Neithea texanus pelecypod from the Duck Creek formation of Texas 

Views of the Mahantango [2016-05-16 09:01:00]  recommend  recommend this post  (144 visits) info

 Cretaceous; US,IE
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This is the pelecypod Neithea texanus from the Duck Creek formation of Texas. I found it in a creek in North Texas last fall. It looks very similar to a scallop but this particular specimen is missing the small "ears" that normally are present next to the beak and are part of the hinge line. Otherwise the shell has a triangular outline with a convex right valve and a slightly concave to flat left valve. There are strong, wide ribs on both valves and the rib pattern is reflected in the margin [...]

Glyptorthis costella brachiopod from the Viola formation from Oklahoma 

Views of the Mahantango [2016-05-10 09:01:00]  recommend  recommend this post  (178 visits) info

 Ordovician; US
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The last, identifiable, fossil that I found during my brief visit to the roadcut in Oklahoma that exposed the Viola formation, is the brachiopod Glyptorthis costella. It has a subrectangular shape with valves that are equally convex and decorated with many fine, closely spaced striae. The margin of the valves is flat with no obvious fold/sulcus structure. The posterior of the shell has a nearly flat, wide interarea. Both valves are recurved in the umbo with the brachial valve moreso than the [...]

Oxoplecia gouldi brachiopod from the Viola formation of Oklahoma 

Views of the Mahantango [2016-05-06 09:01:00]  recommend  recommend this post  (164 visits) info

 Ordovician; US
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Among the rubble that was the eroding rock of the Viola formation I found a few good examples of the brachiopod Oxoplecia gouldi. The shell is subrectangular to suboval in outline with both valves roughly equal in size and depth. There is a wide, shallow fold and sulcus structure present along with fine, widely spaced radiating striae on the surface of the valves. The pedicle valve extends out and curves back over the brachial valve. There is a wide, triangular interarea on the pedicle valve [...]

Lichenalia torta? bryozoan from the Moscow formation of New York 

Views of the Mahantango [2016-04-29 13:50:00]  recommend  recommend this post  (159 visits) info

 Devonian; RU,US
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Within the rocks of Fall Brook, near Geneseo, NY, sometimes you'll find odd dark colored fossils that look as though someone poured chocolate on the rock. I knew it was a fossil of some kind but getting a piece to reveal itself face up was not an easy task. So I kept a few pieces in the hopes that one day I would figure out what it could be. Now I may have an answer. While I was looking through the plates within the Paleontology of New York, volume  VI, I came across an illustration that [...]

Nucelospira ventricosta from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-04-01 09:01:00]  recommend  recommend this post  (132 visits) info

 Devonian; US
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This little, rounded shell appears to be a Nucleospira based on the shape.  I found it in the Bois d'Arc formation in Oklahoma. The brachial valve is slightly smaller and less convex than the pedicle valve but both are nearly perfectly circular. My fossil is smooth on the surface of the valve, at least in the areas where there is still shell, but it should be covered with lots of tiny, needle like spines. They likely either did not preserve well or were weathered away. There is a small [...]

Kozlowskiellina (Megakozlowskiella) velata brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-03-28 09:01:00]  recommend  recommend this post  (184 visits) info

 Devonian; US
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This highly decorated shell has a very long name: Kozlowskiellina (Megakozlowskiella) velata. It is related to Kozlowskiellina perlamellosa which is found in the Helderberg fauna of New York. The shell is triangular to half moon shaped with each convex valve featuring coarse plications (generally three on each side of the fold and four on each side of the sulcus). The shell is further decorated with strong concentric growth lamellae. The pedicle valve recurves, extends past the brachial [...]

Atrypina hami brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-03-16 08:01:00]  recommend  recommend this post  (184 visits) info

 Devonian; US
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Atrypina hami is an easy brachiopod to ID due to the wavy nature of the shell. It has a generally rounded appearance with flat to slightly concave brachial valve and a convex pedicle valve.  The pedicle valve extends beyond the pedicle valve and curves just slightly at the umbo. both valves have widely spaced, concentric growth lines and a handful of very wide ribs that affect the margin of the shell. It's this wavy appearance and the obvious growth lines that make this brachiopod [...]

Atrypa oklahomensis brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-03-07 09:01:00]  recommend  recommend this post  (164 visits) info

 Devonian; US
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The brachiopod genera Atrypa makes an appearance in the Bois d'Arc formation, as one would expect. It's pretty much an index fossil for the Devonian period as far as I'm concerned. In this case we have Atrypa oklahomensis. The shell is rounded with a very convex brachial valve and a slightly convex to flat pedicle valve. The surface of both valves have regularly spaced ribs and fine concentric growth lines. There is a small fold and sulcus present to some degree on every specimen I have found [...]

Rhipdomelloides oblata brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-02-27 09:01:00]  recommend  recommend this post  (193 visits) info

 Devonian; US
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Perhaps the most common fossil brachiopod to be found in the Bois d'Arc formation is Rhipidomelloides oblata. Most are small but some can get about an inch in width. The shell is rounded to subrectangular with both valves generally convex. A gentle curve is sometimes present in the anterior margin. The pedicle valve has a beak that recurves over the brachial valve. Both valves have fine striae and concentric lines decorating their surface.Pedicle valveAnteriorBrachial valvePosteriorProfileWhile [...]

Further exploration of the boundary between truth and untruth 

Earth and Mind Blog [2016-02-10 07:00:00]  recommend  recommend this post  (161 visits) info
Christopher Columbus is said to have balanced an egg on its end by cracking the shell, to demonstrate how an insight can be obvious once the trick is known. The story is untrue in a literal sense and yet it

Anthracospirifer sp. brachiopod from the Chainman formation of Utah 

Views of the Mahantango [2016-01-28 09:01:00]  recommend  recommend this post  (189 visits) info

 Carboniferous; US,IN
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I believe this next brachiopod fossil is Anthracospirifer sp.. It comes from the Chainman formation at Conger Springs in Utah. The shell is missing part of a "wing" but enough is left to help identify it. The pedicle and brachial valves are equally convex, rectangular shaped and have coarse plications. A sulcus on the pedicle valve corresponds with a single fold on the brachial valve. The pedicle valve has a wide interarea with a recurved beak.Brachial valveAnteriorPedicle [...]

Inner View of Orthotetes Brachiopod Fossil 

Louisville Area Fossils [2016-01-20 03:30:00]  recommend  recommend this post  (675 visits) info

 Carboniferous; US
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This image shows inside of the shell of an Orthotetes keokuk brachiopod fossil. It was found in the Edwardsville Formation of Floyd County, Indiana, USA. The fossil dates to the lower Carboniferous (Mississippian) Period. Thanks Kenny for the

Crurithyris sp.? brachiopod from the Chainman formation of Utah 

Views of the Mahantango [2016-01-19 09:01:00]  recommend  recommend this post  (212 visits) info

 Carboniferous; US
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This next brachiopod looks very similar to a genera called Crurithyris that is present in the Pennsylvanian. I can't locate any literature or examples from the Chainman formation at Conger Springs, Utah that indicate this could be any other genera. So I am tentatively labeling this as Crurithyris sp. The shell is small, wider than long with a very convex pedicle valve and a slightly convex brachial valve. The valves are smooth with no obvious ornamentation. The pedicle valve recurves back over [...]

Placopecten clintonius pelecypod from the Yorktown formation of Virginia 

Views of the Mahantango [2015-09-03 09:01:00]  recommend  recommend this post  (218 visits) info

 Neogene; US
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This shell was among a number of Chesapectin jeffersonius specimens and it caught my eye due to the difference. A little research leads me to believe that this is a Placopecten clintonius pelecypod as it exists within the Yorktown formation at the same horizon as C. jeffersonius. The shell is smaller than C. jeffersonius and the radial ribs are both more numerous and finer.This specimen came from the Yorktown Formation, which is Neogene in age (Pliocene epoch, Zanclean stage), along the James [...]

Coelospira concava or Atrypina imbricata brachiopod from the Kalkberg formation of New York 

Views of the Mahantango [2015-08-26 09:01:00]  recommend  recommend this post  (220 visits) info

 Devonian; DE,US,PL
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This is the last fossil that I am profiling from the Kalkberg formation for now. I'm very surprised at the number of species that I found from this formation considering that I have only visited it once and only at a single roadcut. The honor of being last goes to a mystery brachiopod. The shell is semielliptical with a convex pedicle valve and concave brachial valve. Both valves have very strong plications but no fold/sulcus structure. There are prominent growth lines visible towards the edges [...]

Paleschara or Leioclesma bryozoans from the Kalkberg formation of New York 

Views of the Mahantango [2015-08-24 09:01:00]  recommend  recommend this post  (213 visits) info

 Devonian; DE,US
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These little bryozoan "chips"were interesting to find and I'm trying to figure out what genera they are. They bear a resemblance to Paleschara sp. but they are not encrusting a shell, which is how I find them most often. they could also be another genera called Leioclesma sp. which looks similar but does not have the encrusting habit. Both of the below specimens did start out colonizing a small hard surface with the first specimen growing over an ossicle from a crinoid stem.Specimen #1 - Dorsal [...]

Platyceras sp. gastropod from the Kalkberg formation of New York 

Views of the Mahantango [2015-08-22 09:01:00]  recommend  recommend this post  (196 visits) info

 Devonian; DE,US
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I've found a few gastropod fossils in the Kalkberg formation that are well preserved, which seems to be typical for most NY Devonian material. The below three specimens all appear to be Platyceras sp. with the first two looking very similar to each other.Specimen #1Specimen #2 - a part of the shell is broken and missing and that truncates the outer spiral.Specimen #3 - This specimen is larger than the other two and may just be an older representative of the same species. The coil is covered [...]

Machaeraria formosa brachiopod from the Kalkberg formation of New York 

Views of the Mahantango [2015-07-25 09:01:00]  recommend  recommend this post  (240 visits) info

 Devonian; AR,DE,US
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This specimen, that I collected from the Kalkberg formation of New York, has given me some trouble trying to identify it but I think I've narrowed it down to Machaeraria formosa. I'm basing this due to the description by Hall in "Paleontology of New York", Vol III part 1, page 236:SHELL subtriangular or transversely oval; lateral margins forming an angle at the beak of about 90° to 110°. Ventral valve somewhat more depressed than the opposite: beak prominent, arched, not strongly incurved. [...]
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