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hndmarshall

is this a clam cast???

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hndmarshall

While I was out cracking that last rock I found this in the drive is this a clam cast???

found in my drive from a gravel load west oh Houston Texas from Brazos river

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Carl

I think it may just be a rock. But it sure comes darned close to a clam!

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Zenmaster6

Has a similar shape but this is indeed a rock. Here is a picture of a bivalve cast I found if that helps at all. best of luck, - John

51745026_852718038232071_8795855759624634368_n.jpg

51759851_373929866723315_2106938787358572544_n.jpg

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DPS Ammonite
5 hours ago, Zenmaster6 said:

Has a similar shape but this is indeed a rock. Here is a picture of a bivalve cast I found if that helps at all. best of luck, - John

51745026_852718038232071_8795855759624634368_n.jpg

51759851_373929866723315_2106938787358572544_n.jpg

You have a brachiopod and not a bivalve. A bivalve would have mirror symmetry along a vertical line (as shown in the last photo). The last photo shows no symmetry since the vertical line is curved.

74F37319-DAA8-4446-9056-7608F0289BC9.jpeg

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Herb

could be a clam cast but probably a stone

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Zenmaster6
21 minutes ago, DPS Ammonite said:

You have a brachiopod and not a bivalve. A bivalve would have mirror symmetry along a vertical line (as shown in the last photo). The last photo shows no symmetry since the vertical line is curved.

74F37319-DAA8-4446-9056-7608F0289BC9.jpeg

THANK YOU. I said it was a brachiopod 9000 times and everyone on this forum kept telling me it was a bivalve. Go look at my identification page for this. 

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Zenmaster6
26 minutes ago, DPS Ammonite said:

You have a brachiopod and not a bivalve. A bivalve would have mirror symmetry along a vertical line (as shown in the last photo). The last photo shows no symmetry since the vertical line is curved.

 

I was thinking that I knew my shells but everyone insists that it was indeed a bivalve. 

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DPS Ammonite
42 minutes ago, Zenmaster6 said:

I was thinking that I knew my shells but everyone insists that it was indeed a bivalve. 

cap1.PNG

 

 

This is a bivalve because the valves have shifted creating the offset beaks. Plus, I recognize from the pronounced concentric ridges that this is an Inoceramid, a clam. Note that if you shift the valves back in their original position you have a vertical plane of symmetry.

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Zenmaster6
36 minutes ago, DPS Ammonite said:

 

I agree on that one. I was just showing that my original thought was brachiopods had a shelf and bivalves were symmetrical 

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hndmarshall

found these online also from texas some are the flatter look similar shape as mine in the start of this thread and the same yellowish orange silt they are the blue background photos ....I also found another but its very worn its in the last two photos this one I am on the fence about.

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Herb

they are not brachiopods, they are worn pelecypod ( bivalve) steinkerns. Possibly Cyprimeria sp or even a Tapes sp  steinkern.

image.png.116c02bc797d1fac071e62f718bb4d19.png

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Max-fossils
13 hours ago, Herb said:

pelecypod steinkerns.

'Pelecypod' is an old word for bivalve ;) 

 

13 hours ago, Herb said:

Lima sp.

How do you come to this conclusion? 

(picture from internet of a Lima lima vulgaris)

46560.jpg.28d61a212e7ffc37ebab7eee00a8de22.jpg

 

 

---/---

 

About the specimen of the OP, I could see it being a bivalve or brachiopod steinkern indeed (but a super worn one). Thing is, it's so worn that the definite features to differentiate the two are gone. However these two grooves make me lean more towards bivalve:

000_0649.thumb.JPG.5422154c51a8aa893b8f00066bf4686f.JPG.8fcf94ad3de1d9f4e14259c410c0809d.JPG

Then again, it's so worn that it might just be a rock, and another of Mother Nature's pseudofossils made to trick us. 

If I were forced to put my money on one thing, then I would still say bivalve steinkern (but note that this is without great conviction)

Whatever it is, it's not a very impressive specimen. :( 

 

Keep hunting, I'm sure you can find better in your area! ;) 

 

Best regards,

 

Max

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Rockwood
On 2/12/2019 at 3:37 PM, hndmarshall said:

found these online also from texas some are the flatter look similar shape as mine in the start of this thread and the same yellowish orange silt they are the blue background photos ....I also found another but its very worn its in the last two photos this one I am on the fence about.

This argument becomes diluted by the fact that it is a group of one. If enough were found in association it would seem to increase the odds of it being a steinkern.

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Peat Burns
15 minutes ago, Max-fossils said:

'Pelecypod' is an old word for bivalve ;) 

 

How do you come to this conclusion? 

(picture from internet of a Lima lima vulgaris)

46560.jpg.28d61a212e7ffc37ebab7eee00a8de22.jpg

 

 

---/---

 

About the specimen of the OP, I could see it being a bivalve or brachiopod steinkern indeed (but a super worn one). Thing is, it's so worn that the definite features to differentiate the two are gone. However these two grooves make me lean more towards bivalve:

000_0649.thumb.JPG.5422154c51a8aa893b8f00066bf4686f.JPG.8fcf94ad3de1d9f4e14259c410c0809d.JPG

Then again, it's so worn that it might just be a rock, and another of Mother Nature's pseudofossils made to trick us. 

If I were forced to put my money on one thing, then I would still say bivalve steinkern (but note that this is without great conviction)

Whatever it is, it's not a very impressive specimen. :( 

 

Keep hunting, I'm sure you can find better in your area! ;) 

 

Best regards,

 

Max

He may have meant Lima (Plagiostoma)

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Archie

Looks like siliceous rocks with the coincidental appearance of a bivalves to me, where they have chipped they look like chert.

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JohnJ
18 minutes ago, Archie said:

Looks like siliceous rocks with the coincidental appearance of a bivalves to me, where they have chipped they look like chert.

Indeed.  The original specimen posted appears to be a lenticular chert nodule.

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Zenmaster6
16 hours ago, Herb said:

they are not brachiopods, they are worn pelecypod steinkerns. Possibly Lima sp.

image.png.116c02bc797d1fac071e62f718bb4d19.png

was that to me or to her?

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Herb
5 hours ago, Zenmaster6 said:

was that to me or to her?

to her

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Herb
8 hours ago, Max-fossils said:

'Pelecypod' is an old word for bivalve ;) 

 

How do you come to this conclusion? 

(picture from internet of a Lima lima vulgaris)

46560.jpg.28d61a212e7ffc37ebab7eee00a8de22.jpg

 

 

---/---

 

About the specimen of the OP, I could see it being a bivalve or brachiopod steinkern indeed (but a super worn one). Thing is, it's so worn that the definite features to differentiate the two are gone. However these two grooves make me lean more towards bivalve:

000_0649.thumb.JPG.5422154c51a8aa893b8f00066bf4686f.JPG.8fcf94ad3de1d9f4e14259c410c0809d.JPG

Then again, it's so worn that it might just be a rock, and another of Mother Nature's pseudofossils made to trick us. 

If I were forced to put my money on one thing, then I would still say bivalve steinkern (but note that this is without great conviction)

Whatever it is, it's not a very impressive specimen. :( 

 

Keep hunting, I'm sure you can find better in your area! ;) 

 

Best regards,

 

Max

pelecypod is used to differentiate from other types of bivalves ie... brachiopods, ostracods etc

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Herb
7 hours ago, Peat Burns said:

He may have meant Lima (Plagiostoma)

what I actually meant was something like a Cyprimeria sp or even a Tapes sp  steinkern. Most people know what a pelecypod is Class Pelecypoda.

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ynot
20 minutes ago, Herb said:

other types of bivalves ie... brachiopods, ostracods

Neither of those are bivalves. One is in a class of its own (brachiopoda) and the other is a  Crustacea 

Bivalves are Mollusc. 

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Herb
15 minutes ago, ynot said:

Neither of those are bivalves. One is in a class of its own (brachiopoda) and the other is a  Crustacea 

Bivalves are Mollusc. 

I am aware of that,  but many people are not, and a brachiopod also has two valves as does an ostracod

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ynot
6 minutes ago, Herb said:

  but many people are not,

And We should endeavor to set them straight. By referring to "other bivalves" You confuse the issue and others less knowledgeable will get the wrong information.

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Herb
13 minutes ago, ynot said:

And We should endeavor to set them straight. By referring to "other bivalves" You confuse the issue and others less knowledgeable will get the wrong information.

do you think anyone was confused when I initially called it a clam steinkern and later a pelecypod steinkern? In most texts and references they will be called pelecypods.

BRACHIOPODS are also bivalves, in that there are two hinged parts to the shell, but the term is usually restricted to true molluscs.

In hmdmarshalls blue backed pix the first one is clam steinkerns and the second one is brachiopods. The other appear to be stones.

 

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ynot
10 hours ago, ynot said:
10 hours ago, Herb said:

other types of bivalves ie... brachiopods, ostracods

Neither of those are bivalves. One is in a class of its own (brachiopoda) and the other is a  Crustacea 

Bivalves are Mollusc. 

@Tidgy's Dad, @RJB, @Shellseeker, @maxfossil,  

(Will not let Me tag anymore members here?)

(Please tag any shell, crustacean or brachiopod collectors You can think of for this survey, thanks.)

 

Should We refer to brachiopods and ostracods as bivalves?

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