Green River Fm fish

[Wrangellian]

I received this piece without any data. Can anyone please confirm that this is from the Green River Formation in Wyoming, and maybe add more specific location/strat detail to that if it's possible to tell? Should I assume it is from the usual place in Kemmerer... and which layer? Or could it be from a different spot entirely? The ID of the fish would be appreciated too.

Sorry about the crummy indoor pic... I tried to get the color balance close to reality.

 

Edited June 3, 2023 by Wrangellian

[Fossildude19]

Eric,

This could be either a Gosiutichthys parvus or Knightia eocaena.  You would have to do fin ray or vertebra counts to be sure. Also size of the fossil is important.

Shapewise and sizewise, I'm leaning towards Gosiutichthys, but I have been wrong before. Fin ray counts are more reliable than my poor perceptions.

 

If it is Gosiutichthys, it is likely NOT from Kemmerer, but rather from Farson, or someplace else.

 

The larger pieces are likely Knightia eocaena.

 

@RJB  @jpc

[Wrangellian]

On 6/3/2023 at 7:31 AM, Fossildude19 said:

Eric,

This could be either a Gosiutichthys parvus or Knightia eocaena.  You would have to do fin ray or vertebra counts to be sure. Also size of the fossil is important.

Shapewise and sizewise, I'm leaning towards Gosiutichthys, but I have been wrong before. Fin ray counts are more reliable than my poor perceptions.

 

If it is Gosiutichthys, it is likely NOT from Kemmerer, but rather from Farson, or someplace else.

 

The larger pieces are likely Knightia eocaena.

 

@RJB  @jpc

Thanks Tim.

Ho boy, I knew it would turn out to be somewhat complicated.

The length of the visible portion fish is about 39mm, and it looks like there should be little more to the tail that could be uncovered.

[RJB]

I'm not sure about this one.  Rock looks different than most GRF rock.  There are some sites that I have not been too and could have different looking rock like the Gosiuteihthys site, but the fish also looks different somehow?  Maybe if some rock was removed by the lower gill area and up to the lower jaw?  My best guess would be the same as Tims.  I'm afraid im not much help.

 

RB

[hadrosauridae]

This doesn't resemble any of the Green River matrix from the Kemmerer area that I have seen.  The GRF does span a large area though, so it could be a different location and specific look to the matrix. 

[Wrangellian]

17 hours ago, RJB said:

I'm not sure about this one.  Rock looks different than most GRF rock.  There are some sites that I have not been too and could have different looking rock like the Gosiuteihthys site, but the fish also looks different somehow?  Maybe if some rock was removed by the lower gill area and up to the lower jaw?  My best guess would be the same as Tims.  I'm afraid im not much help.

 

RB

 

12 hours ago, hadrosauridae said:

This doesn't resemble any of the Green River matrix from the Kemmerer area that I have seen.  The GRF does span a large area though, so it could be a different location and specific look to the matrix. 

 

Hmmm... Do you think it's the low light angle I used for the pic? It does make it look more 'lumpy' than it is.

I'll try some more photos incl. the back, in sunlight tomorrow.. that might make a difference.

[hadrosauridae]

No, the GRF, especially the Kemmerer area, is known for its clean splits along bedding plains.  Your slab is very rough.  Lighting angles wont change its nature.  I can go pull a 50 slabs and theyll be as flat a chalk boards.

[Yoda]

I only have a handful of the GRF fish. 
But they are all like this one. 
Quite smooth. And the matrix is very pale 

 

 

[jpc]

There are many other layers of GRF.  I would not rule it out based on peoples' knowledge of only the split fish beds, which is what the above fish comes from. 

 

Tim's analysis is spot on.  I am not an expert at IDing Knightia from Goscuitichtyes so I will not try.    

[Wrangellian]

Are we confident enough to say it's from the Green River Fm at least? or maybe it's from Princeton BC or some other place? (That is a possibility as the collector had a few other things from that region too, but I don't know if those fish occur in the Allenby Fm as well, or not)

Edited June 6, 2023 by Wrangellian

[Wrangellian]

Hopefully these outdoor/sunlit photos help to see what we're looking at, incl. a macro photo of the fish:

The whole piece btw is 82 x 63mm, x 5mm thick, if that helps.

 

 

 

Edited June 6, 2023 by Wrangellian

[Wrangellian]

Do the pics not help to clarify anything? Do I need to reply to people or do shout outs?

@Fossildude19 @hadrosauridae @jpc @RJB

[Fossildude19]

Thanks Eric, I had not seen the new photos.

I count 34 vertebrae, and 13 anal pterygiophores.  That would make this a Gosiutichthys parvus.

 

See the reference chart in this post:

 

 

[jpc]

2 hours ago, Fossildude19 said:

Thanks Eric, I had not seen the new photos.

I count 34 vertebrae, and 13 anal pterygiophores.  That would make this a Gosiutichthys parvus.

 

See the reference chart in this post:

 

 

I would go with Tim's analysis.  He actually takes the time to do the research.  Thumbs up emoji for Tim. 

 

[Wrangellian]

12 hours ago, Fossildude19 said:

Thanks Eric, I had not seen the new photos.

I count 34 vertebrae, and 13 anal pterygiophores.  That would make this a Gosiutichthys parvus.

See the reference chart in this post:

Thanks again Tim - straight to the goods. I appreciate that. Thumbs up emoji

 

10 hours ago, jpc said:

I would go with Tim's analysis.  He actually takes the time to do the research.  Thumbs up emoji for Tim.

Yes, I don't know where I'd be if I didn't have access to those like Tim who specialize in things I do not - It often takes me a while to research something and penetrate the jargon etc. that is needed to make an ID. I have a bunch more recently-received fossils that I would like more info on, and it will take me long enough just to photo and post them. I'd be old and grey by the time I got all the research done if I couldn't just ask someone who has it at their fingertips. And I assume those people don't mind offering their expertise if they have it, otherwise they wouldn't be here!

 

So I gather this is Mid-Eocene, from the Lake Gosiute deposits of Wyoming. That narrows it down. If I can't narrow it down any further (to a specific site/layer, then at least I have this much on it - helluva lot better than what I had before which was no more than an assumption of being from the Green River Fm.

[jpc]

I believe Gosiutichyes is indeed only known from the Lake Gosiute portion of the GRF.  

[Wrangellian]

21 hours ago, jpc said:

I believe Gosiutichyes is indeed only known from the Lake Gosiute portion of the GRF.  

OK, thanks. I guess we can't narrow it down any further based on the type of rock, except that it doesn't appear to be from the usual site in Kemmerer (whatever that is - split fish layer or 18" layer?)

 

[jpc]

It is also not from the best known Gosuitichtyes site, which is a very dense (dense in fish carcasses, not mass divided by volume) mass mortality layer. 

[Wrangellian]

20 hours ago, jpc said:

It is also not from the best known Gosuitichtyes site, which is a very dense (dense in fish carcasses, not mass divided by volume) mass mortality layer. 

OK. I guess you mean the site where this plate is from. (not the best pic):

I've had this one a while and it's had 3 different IDs since I got it - now I'm told Gosiutichthys sp. (parvus also? These are even smaller than the one in question), and I see the difference in matrix - this stuff is more finely layered and a lighter yellowish color.

 

I also have these smaller pieces - should I assume they are from the same site as this above? They look like the same material or at least much more alike than the one that started this topic. I've shown all these on TFF before.

 

[Randyw]

I know i’m late to the party but i believe the partial fish in the upper left of the original picture is a disarticulated diplomystus….

[Wrangellian]

On 6/11/2023 at 7:05 PM, Randyw said:

I know i’m late to the party but i believe the partial fish in the upper left of the original picture is a disarticulated diplomystus….

Thanks. That doesn't contradict anything that's been said about the possible origin of the piece, does it?

[Randyw]

1 hour ago, Wrangellian said:

That doesn't contradict anything that's been said about the possible origin of the piece, does it?

Nope. But while they are found world wide (i believe) they are most commonly found in the vanished lakes of the grf formation.. I think its a diplo dentatus wich would be a grf fish, it doesn’t look right for a diplo shengliensis from china or a diplo birdi from lebonon.. so if i’m right it would further put it in the grf series of lakes.

Edited June 13, 2023 by Randyw

[Wrangellian]

3 hours ago, Randyw said:

Nope. But while they are found world wide (i believe) they are most commonly found in the vanished lakes of the grf formation.. I think its a diplo dentatus wich would be a grf fish, it doesn’t look right for a diplo shengliensis from china or a diplo birdi from lebonon.. so if i’m right it would further put it in the grf series of lakes.

Right, Thanks again... So the Diplo is a worldwide genus but the species D. dentatus is only found in the GRF? I guess more importantly the Gosiutichthys is only found in the Lake Gosiute portion of the GRF. Just don't know the exact site.

If it helps anyone narrow down the location further for me, it likely was found in the 20th century from a site known to collectors, probably from a guidebook or the like. I don't know how many such sites there would be - maybe still too many.

Edited June 13, 2023 by Wrangellian