Knightia alta

[MotloAstro]

Hi everyone, are parts of this Knightia painted? Bought from a pretty reputable dealer, not a dubious random online seller.

 

Edited May 8, 2019 by MotloAstro

[Pixpaleosky]

It is not painted, but is has received a layer of varnish all over in order to hide the white of the stone where there are no scales or where the stone has not been entirely removed

[MotloAstro]

34 minutes ago, Pixpaleosky said:

It is not painted, but is has received a layer of varnish all over in order to hide the white of the stone where there are no scales or where the stone has not been entirely removed

Thanks

[Fossildude19]

@MotloAstro

 

I think that this is a Knightia eocaena, not a Knightia alta, though.

 

EDIT: A revision of the fossil genus Knightia, with a description of a new genus from the Green River Formation (Teleostei, Clupeidae). American Museum novitates ; no. 2731 Grande, Lance. 1982

[MotloAstro]

33 minutes ago, Fossildude19 said:

@MotloAstro

 

I think that this is a Knightia eocaena, not a Knightia alta, though.

 

EDIT: A revision of the fossil genus Knightia, with a description of a new genus from the Green River Formation (Teleostei, Clupeidae). American Museum novitates ; no. 2731 Grande, Lance. 1982

Thanks a lot.

[digit]

I've seen many a Knightia with a full accompaniment of scales--I've also seen ones that have been badly painted in to "restore" missing bits. this one does not look artistically "enhanced" to me. If you have the specimen in hand, looking it over under magnification should convince you that the scales are really there by looking at the texture--there should be no dark colored area that has the same texture as the oil shale background matrix only bone or scale.

 

These are the most common fishes from the Green River Formation and assuming you got it for a reasonable cost, you should be happy with a greatly detailed fish from the Eocene.

 

Cheers.

 

-Ken

[Mark Kmiecik]

I have prepped a few Green River fish and I don't think this specimen has any paint or varnish on it at all. The "darker" part of the fish between the bones where much of the time you find mostly or only matrix, appears to be covered by a blotchy surface, which is actually preserved scales that lie between the fish and the matrix. In other words, the scales on the other side of the fish. It's great to have a specimen with that feature. 

 

P.S. -- As in extant scaly fish you should be able to count the growth rings on some of the scales to determine how old the fish was when it died. A jeweler's loupe, or other 10x or better lens for that.

[Fossildude19]

4 hours ago, Mark Kmiecik said:

I have prepped a few Green River fish and I don't think this specimen has any paint or varnish on it at all. T

I believe this was coated with a sealant of some sort. 
I see what looks like overlapping stain from the coating.

 

[digit]

Most of these are coated so that the bones and scales don't peel off. It was Green River Formation fossils that rekindled my interest in fossils some dozen years back (note the Diplo as my avatar photo). Back in the day, the suggested method was 1 part white glue diluted in 10 parts water. The entire block was submerged till saturated and then allowed to drip off excess and dry. Looking back, this sort of a consolidant is likely to discolor with age and I'd probably use different sealers these days but I believe all Green River Formation fossils tend to be sealed (for freshness).

 

Likely, this specimen is sealed only over the fossil itself as Tim as spotted the edge of the sealant visible in the photo.

 

 

Cheers.

 

-Ken

[Mark Kmiecik]

1 minute ago, Fossildude19 said:

I believe this was coated with a sealant of some sort. 
I see what looks like overlapping stain from the coating.

You've got good eyes. I couldn't see that if you told me it was there. I don't see it at all in the positive, but it's there plain as day in the negative. And yes I am wearing my bifocals! It sucks to be 68. I just learned how to check photos for evidence of having been painted. Would there be any way to tell if the prepper had not gotten any on the matrix?

[Mark Kmiecik]

2 minutes ago, digit said:

Most of these are coated so that the bones and scales don't peel off. It was Green River Formation fossils that rekindled my interest in fossils some dozen years back (note the Diplo as my avatar photo). Back in the day, the suggested method was 1 part white glue diluted in 10 parts water. The entire block was submerged till saturated and then allowed to drip off excess and dry. Looking back, this sort of a consolidant is likely to discolor with age and I'd probably use different sealers these days but I believe all Green River Formation fossils tend to be sealed (for freshness).

 

Likely, this specimen is sealed only over the fossil itself as Tim as spotted the edge of the sealant visible in the photo.

 

 

Cheers.

 

-Ken

Back in the day they used diluted albumen or yellow dextrin to coat Mazon Creek specimens. They don't have a tendency to peel or crumble, so I believe it was merely a way to increase contrast to make the specimen stand out. I have prepped about a dozen Green River fossils and still have some that I'll probably never get around to, but while I was involved with them I never came across any discussion from the seller or online about any preservative coatings. Is this something new? 

[Fossildude19]

It's been done by some dealers for quite some time. 

LINK

[MotloAstro]

Thanks everyone - the scales indeed seem to have a different texture than the matrix. I hope I'll be able to check its age sometime in the future Mark, thanks for the tip, but I don't have any suitable magnifiers to do it now unfortunately.

[Mark Kmiecik]

4 hours ago, MotloAstro said:

Thanks everyone - the scales indeed seem to have a different texture than the matrix. I hope I'll be able to check its age sometime in the future Mark, thanks for the tip, but I don't have any suitable magnifiers to do it now unfortunately.

You can get good quality 10x jeweler's loupe online for cheap. Less than 10x may not be enough, but 10x is what I have and it is adequate.