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Hoploscaphites Landesi?


sander

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Dear Forum members,

I bought this ammonite last summer, on the nametag it said:

Garniericeras, Rybinsk, Jurassic.

There is just one problem; it doesn't look like a Garniericeras at all. I have been searching for 3 months which genus it could be from Rybinsk, but yesterday I stumpled upon a photo of a scaphites from the Pierre shale, which almost looks the same and has the exact same preservation. So I think it looks more like a Hoploscaphites landesi, or a relative of it from the Fox Hills Fm. or Pierre Shale Fm. Do you think the same as well?

Thanks in advance,

Sander

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The photos are kind of dark, but I agree the mode of preservation and the aspect of the specimen fits well with a Fox Hill scaphitid.

Don

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These photo's must be better. I hope so one can put a name on it and maybe the formation from which it comes. (perhaps even the findspot, I dont know how many findspots cut through these formations).

Thanks,

Sander

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Yes, but they do not look like this fossil, I really think it is a Scaphite of some sort, and the Scaphites that I have seen from Russia have been preserved rather differently. I had hoped that there would be a Pierre shale / Fox hills expert here, does anyone know an expert on this formation?

Thanks,

Sander

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Judging by only photos, I would say there is a very good chance this is a Pierre Shale fossil. Preservation is correct, and without looking through Neal Larson's book on Pierre Shale ammonites to ID it, it looks an awful lot like the stuff I get in eastern Wyoming.

Edited by jpc
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Hi JPC,

Have you found time to look into that book? I would really like to know which ammonite this is. On the web I only see a few species that have much small bumps on them, while this one only has four smaller ones while nearing the place where the animals head would have sticked out.

Thank you for your reply,

Sander

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I have that book at home. I will have a look later and let you know what I can determine from it.

A fossil hunter needs sharp eyes and a keen search image, a mental template that subconsciously evaluates everything he sees in his search for telltale clues. -Richard E. Leakey

http://prehistoricalberta.lefora.com

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  • 2 weeks later...
  • 1 month later...

Hi Sander, I must apologize. I completely forgot to have a look. Let me grab my book and have a look. Stay tuned.........

A fossil hunter needs sharp eyes and a keen search image, a mental template that subconsciously evaluates everything he sees in his search for telltale clues. -Richard E. Leakey

http://prehistoricalberta.lefora.com

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So I have been looking through my Pierre shale book and I am pretty confident that it is Hoploscaphites Landesi. I am by far no expert on these so this is my educated guess based on the reference material that I have. I do agree that it looks very much like pierre shale material in the way it is preserved. I hope this helps.

A fossil hunter needs sharp eyes and a keen search image, a mental template that subconsciously evaluates everything he sees in his search for telltale clues. -Richard E. Leakey

http://prehistoricalberta.lefora.com

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  • 4 weeks later...
  • 6 months later...

Dear Forum members,

I bought this ammonite last summer, on the nametag it said:

Garniericeras, Rybinsk, Jurassic.

There is just one problem; it doesn't look like a Garniericeras at all. I have been searching for 3 months which genus it could be from Rybinsk, but yesterday I stumpled upon a photo of a scaphites from the Pierre shale, which almost looks the same and has the exact same preservation. So I think it looks more like a Hoploscaphites landesi, or a relative of it from the Fox Hills Fm. or Pierre Shale Fm. Do you think the same as well?

Thanks in advance,

Sander

You said that was Jurassic. Yeah. That's probably not Hoploscaphites. Hoploscaphites landesi is only known from the Baculites compressus zone of the Late Cretaceous (Campanian) age Pierre Shale in Pueblo, Colorado and Meade County, South Dakota, along with Jeletzkytes nodosus. But good luck identifying your ammonite.

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On 7/30/2015 at 2:14 PM, Eocenecarnage said:

...Hoploscaphites landesi is only known from the Baculites compressus zone of the Late Cretaceous (Campanian) age Pierre Shale in Pueblo, Colorado and Meade County, South Dakota, along with Jeletzkytes nodosus...

 

 

Actually, Hoploscaphites landesi is recorded outside of Colorado and South Dakota. It was originally described from Canada, the holotype is from Saskatchewan:

 
Hoploscaphites landesi sp. nov.
 
Holotype: The almost complete specimen figured on Plate 1, figs. 12-14, is from the Bearpaw Formation, ? Demaine Sandstone, South Saskatchewan River, opposite the mouth of Swift Current River, Saskatchewan (coll. T.C. Weston, 1889; GSC 5342a) (GSC loc. 97988).
 
Derivation of name: The species is named for Dr. R.W. Landes who made collections of fossil invertebrates and studied the stratigraphy of the Bearpaw Formation in the southern Alberta plains.
 
Riccardi, A.C. (1983)
Scaphitids from the upper Campanian - lower Maastrichtian Bearpaw Formation of the western interior of Canada.
Geological Survey of Canada Bulletin, 354:1-103
 
 
 

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The family (of heteromorph ammonites) Scaphites inahbited the Cretaceous period seas, yes...However we can explain the mistake because the seller identified it as Garniericeras, that live during the Jurassic period...So, I agree with Holoscaphites landesi hypotesis,also.

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Actually, Hoploscaphites landesi is recorded outside of Colorado and South Dakota. It was originally described from Canada, the holotype is from Saskatchewan:

Hoploscaphites landesi sp. nov.

Holotype: The almost complete specimen figured on Plate 1, figs. 12-14, is from the Bearpaw Formation, ? Demaine Sandstone, South Saskatchewan River, opposite the mouth of Swift Current River, Saskatchewan (coll. T.C. Weston, 1889; GSC 5342a) (GSC loc. 97988).

Derivation of name: The species is named for Dr. R.W. Landes who made collections of fossil invertebrates and studied the stratigraphy of the Bearpaw Formation in the southern Alberta plains.

Riccardi, A.C. (1983)

Scaphitids from the upper Campanian - lower Maastrichtian Bearpaw Formation of the western interior of Canada.

Geological Survey of Canada Bulletin, 354:1-103

My bad.

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Judging by only photos, I would say there is a very good chance this is a Pierre Shale fossil. Preservation is correct, and without looking through Neal Larson's book on Pierre Shale ammonites to ID it, it looks an awful lot like the stuff I get in eastern Wyoming.

It probably isn't from the Pierre Shale. As I said Hoploscaphites landesi only occurs in the Baculites compressus Zone (74.21 MYA) of the Pierre Shale. The Pierre shale only occurs in the U.S, Canada, and possibly Mexico. Since yours occurs in Rybinsk, Russia, I would say it's almost impossible for yours to have come from the shale. I've posted a picture below showing one on my Hoploscaphites (either landesi or brevis) from SD, it is from Pierre Shale, and it looks dramatically different from yours. For one yours is too iredecent and the matrix rock is brown not gray

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eocenecarnage... keep in mind that color is not an important factor in fossil ID. There are many Pierre Shale sites that preserve the color as nicley as the original post. As well, there are many Pierre shale sites where the rock is browner than the typical gray.

sander... if you are still paying attention, we could use a picture of the edge-on view... how fat is it and how rounded/square are the 'shoulders'? I am looking at Larson's book, and honestly, I have a hard time IDing specimens to species with the book, but yours looks too rounded on the shoulders to be landesi. The specimen looks like a scaphitid. I know nothing about Russian ammonites, but I know they have some irridescent ones like we have here in the Pierre Shale. Also it is incomplete... missing the living chamber, so it maybe hard to pin down.

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eocenecarnage... keep in mind that color is not an important factor in fossil ID. There are many Pierre Shale sites that preserve the color as nicley as the original post. As well, there are many Pierre shale sites where the rock is browner than the typical gray.

sander... if you are still paying attention, we could use a picture of the edge-on view... how fat is it and how rounded/square are the 'shoulders'? I am looking at Larson's book, and honestly, I have a hard time IDing specimens to species with the book, but yours looks too rounded on the shoulders to be landesi. The specimen looks like a scaphitid. I know nothing about Russian ammonites, but I know they have some irridescent ones like we have here in the Pierre Shale. Also it is incomplete... missing the living chamber, so it maybe hard to pin down.

Is it brevis?
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