Marine Reptile Bone

[Harry Pristis]

Are there any marine reptile collectors here? This is a pic of a bone I collected out of the Pierre Shale in South Dakota. I'm pretty certain that it is a bone from the flipper ("flipper bone"? "metacarpal"?) of a large marine reptile. I don't know if these things are identifiable beyond that -- any ideas?

-----Harry Pristis

Edited September 18, 2007 by Anson

[Uncle Siphuncle]

Harry

Looks like you get around quite a bit collecting. Can't help you with the bone but it is a cool piece. Try Mike Everhart at the Oceans of Kansas website. He may have some comparative Niobrara pieces for you to look at. Did you find some good nacreous ammonites like Discoscaphites, Sphenodiscus, Placenticeras, or Jeletzkytes while you were there? Any Dakoticancer overana crabs? I'd love to collect the Pierre Shale, Fox Hills Sandstone, and Bearpaw Shale up that way sometime.

[Harry Pristis]

I traveled quite a bit, Dan. Perhaps that is one reason my collection is so eclectic. Mike Everhart has published a book now by the same name, OCEANS OF KANSAS. I should contact him or buy his book.

Here's my favorite ammonite from South Dakota.

-----Harry Pristis

[Uncle Siphuncle]

Killer ammonite; more exquisitely preserved than many of the Texas steinkerns. We don't get many with original shell outside of the Woodbine/Eagle Ford groups of the DFW area but we do have some cool pyritized ones from the Del Rio, Weno, Pawpaw, etc.

Did my personal email get through to you? It was the first one I've attempted through this website.

[Harry Pristis]

Pyritized fossils are very interesting. They may retain exquisite detail, and they buff up so that they really stand out in a drawer. Unhappily, "pyrite disease" seems to be incurable.

For a long time I thought that pyrite disease was a chemical reaction involving water ("humidity") and sulphur in the pyrite leading to sulphuric acid which ate up the fossil. I tried everything I could think of to interrupt that cycle. Nothing worked.

The latest thinking is that pyrite disease is caused by an iron-eating bacteria -- amazing, huh! I haven't heard of any reasonable conservation measures that will protect pyritized fossils from iron-eating bacteria.

Do you have this problem with Texas ammonites? Here's a pic of three pyritized ammonites from France and Germany that I have been watching since I noticed their infection.

---------Harry Pristis

[Gatorman]

Harry I read an article on this somewhere :huh: but the person that wrote it had found a way to significantly reduce the reaction time... i just cant remember what it was

[ebrocklds]

i haven't had a chance to try his but i was thinking you may be able to seal it with a polyvinyl acetate. this would keep the oxygen out, either stopping the reaction or killing the bacteria? i do know that on certain fossils that turn green from the use of glue accelerant the sealing method stops the greening. it is worth a try.

brock

[Uncle Siphuncle]

Guys

We do have this problem on TX fossils. I've seen it first hand with pyritized micromorphic ammonites from the Del Rio formation at the Waco Pit. I took my best, cleanest specimens and put them in a Riker mount. So far I don't see any oxidation. Then again I've only been seriously collecting for about 4 years so perhaps I haven't had enough time to see the fruits of my labor go to pot. Anyway, there are several Lower K formations in Central and North TX featuring pyritized material. I haven't seen any of the "golden" ammonites or pyritized crabs from the Pawpaw fm disintegrate. Ditto for the pyritized Macrasters of the Georgetown fm with the big cubic crystals.

[Harry Pristis]

i haven't had a chance to try his but i was thinking you may be able to seal it with a polyvinyl acetate. this would keep the oxygen out, either stopping the reaction or killing the bacteria? i do know that on certain fossils that turn green from the use of glue accelerant the sealing method stops the greening. it is worth a try.

brock

That sounds so logical, Brock. That was my major effort when I thought I could disrupt the putative water-->sulphur-->sulphuric acid cycle. I heated the ammonites with my infra-red lamp to drive off moisture, then sealed them with Butvar-76 in an acetone solution.

I have not considered using polyvinyl acetate (white glue); after all, I considered water a significant part of the problem. I'm not confident that white glue is any more effective than Butvar. Has anyone here tried white glue for this purpose?

--------Harry Pristis

[ebrocklds]

i am not sure that we are talking about the same polyvinyl acetate. what i refer to is vinac or paraloid in acetone. i am young so maybe i haven't heard that they are refered to as white glues? i don't know. but i know vinac is one of my favorite consolidants becase it is 100% reversible and you can make it as thick or thin as you want. i wish you luck to find a solution

brock

Rescue of decomposing specimens with ethanolamine thioglycollate:

In 1984 Lorraine Cornish and Adrian Doyle from the British Museum of Natural History in London introduced ethanolamine thioglycollate, or short “ET”, as a novel treatment against pyrite decay. ET is normally used to perm hair, but can do wonders in rescuing affected fossils. The pale pink ET liquid smells rather unpleasant and is moderately toxic. Therefore, it should only be used outside with proper ventilation and safety gear such as PVC gloves and eye goggles. A 5% solution of ET in industrial spirit (95% alcohol) is used to treat oxidizing fossils. The fossils are soaked in the solution for about 1-2 hours. During this time, the color will change from clear to purple, indicating neutralization of the specimen and the formation of various organic complexes (hence the purple color). The treatment should be repeated until the color reaction no longer appears. A final wash with spirit will remove remaining ET (and the smell of it). Before re-introducing the fossil into the collection, the storage container should be replaced and the label laminated, if it was in contact with the fossil. I have successfully used this method; however, a few specimens required a second round of treatment.

[ebrocklds]

http://www.mindat.org/mesg-6-36559.html

there is a link to a mineral site talking about several different ways to stop the problem.

i will post more as i find them

[Harry Pristis]

i am not sure that we are talking about the same polyvinyl acetate. what i refer to is vinac or paraloid in acetone. i am young so maybe i haven't heard that they are refered to as white glues? i don't know. but i know vinac is one of my favorite consolidants becase it is 100% reversible and you can make it as thick or thin as you want. i wish you luck to find a solution

brock

Rescue of decomposing specimens with ethanolamine thioglycollate:

In 1984 Lorraine Cornish and Adrian Doyle from the British Museum of Natural History in London introduced ethanolamine thioglycollate, or short “ET”, as a novel treatment against pyrite decay. ET is normally used to perm hair, but can do wonders in rescuing affected fossils. The pale pink ET liquid smells rather unpleasant and is moderately toxic. Therefore, it should only be used outside with proper ventilation and safety gear such as PVC gloves and eye goggles. A 5% solution of ET in industrial spirit (95% alcohol) is used to treat oxidizing fossils. The fossils are soaked in the solution for about 1-2 hours. During this time, the color will change from clear to purple, indicating neutralization of the specimen and the formation of various organic complexes (hence the purple color). The treatment should be repeated until the color reaction no longer appears. A final wash with spirit will remove remaining ET (and the smell of it). Before re-introducing the fossil into the collection, the storage container should be replaced and the label laminated, if it was in contact with the fossil. I have successfully used this method; however, a few specimens required a second round of treatment.

Thanks for the research, Brock, posting this pyrite disease "cure" and the Minedat posts. After all is said and done, there is no simple treatment nor a complete cure. I am going to stay away from pyritized specimens.

White glue (Elmer's, "school glue") IS the water-soluble form of polyvinyl acetate. Apparently, Vinac is an acetone-soluble form of polyvinyl acetate. I didn't realize that. I don't know the chemical differences.

I have never tried Vinac, as I've had access to and have been satisfied with Butvar B-76 (polyvinyl butyral). I don't think using Vinac will have much impact on pyrite disease (I know that Butvar didn't).

----Harry Pristis

[mosasaur]

Harry, I am familiar with Clidastes, a mosasaur, and this does not quite match. A plesiosaur might be the answer - let me do some research. Of course, it could be another kind of mosasaur!!

Kenneth Quinn

[LanceH]

HarryPristis,

You could also email a pic to Mike Polcyn at Southern Methodist University (SMU) in Dallas who's a mosasaur expert.

Here's a Youtube video of him in action identifing Roz's mosasaur bones.

[Roz]

" It is a neck vert from the elasmosaurid. It was the largest and most advanced of the long-necked plesiosaurs. It is the base of the neutral canal, where the nutritive formaminae are visible." That is the ID I received regarding the one I found pictured., sure looks like yours..how exciting. I love them!

[Mike Owens]

" It is a neck vert from the elasmosaurid. It was the largest and most advanced of the long-necked plesiosaurs. It is the base of the neutral canal, where the nutritive formaminae are visible." That is the ID I received regarding the one I found pictured., sure looks like yours..how exciting. I love them!

Interesting specimen! May I inquire as to the general area it was found in? What is the height?

[Roz]

Yes, I found it in southwestern, Arkansas. The length is 3 and a half inches. Near Arkadelphia, AR

[ral514]

http://www.mindat.org/mesg-6-36559.html

there is a link to a mineral site talking about several different ways to stop the problem.

i will post more as i find them

Hi - I registered just to respond to this thread, as I've done some experimenting with "Iron breathing" bacteria from my own backyard. I'm not an expert, just someone with a little knowledge and a very stubborn DIY streak, but maybe what I learned can help you to find a solution.

Based on some internet research, I decided to grow a batch of my own Geobacter metallreducens. Most of the information I used came from articles like this one - second page of National Geographic News article - which is worth reading from page one, but the parts pertinent to dealing with "Pyrite Disease" can be skimmed at the link to the second page.

I live in a city that was an uninhabitable peat bog only 60 or so years ago. I can't find any details (yet) as to the methods used to reclaim the land, but most of the classic "wetland" characteristics remain, eg. claylike soil, bog iron chunks, plant types, etc... I dug up some chunks of heavy gray clay that are a few inches below the surface throughout my yard because it resembled descriptions I'd found of geobacter bearing wetland soils. I let the chunks of "clay" dry, then put them in a glass jar with some rusty metal - tools, nails, bolts. I added vinegar to the jar because I couldn't find a stronger form of acetic acid, so I allowed extra time for the reaction, and added more vinegar when the action settled down.

The action, while slower than the reaction described in the article, nevertheless began immediately. Bubbles began to rise from the chunks of clay. Now one would expect some bubbling when adding liquid to dry soil of any kind, but this bubbling action was sustained. It was like watching yeast proof in warm sugar water. After a few days of feeding my bacteria, I checked my rusty tools, and found that they were covered in fine, black particles that I could wipe away with my fingers. In particular, the old wood files gave the best results. They were as sharp as they had been when they were new, as all of the oxidation had transformed and lifted away from the fine edges. Not all traces of rust were gone, though I think that more time, or stronger acetate, would have cleaned it all away. Even so, the difference was amazing.

Basically, if geobacter is responsible for the problem with your fossils, then cutting off the oxygen supply won't help much. This type of bacteria lives in oxygen depleted environments normally, by extracting oxygen from oxidized metals in it's environment. Any specimen you have will already have oxidized minerals, even if only in microscopic amounts, throughout the structure. When the bacteria breathes those oxygen molecules out, it breaks up those tiny particles that hold the fossil together, and they'll just crumble away.

Likewise, the idea of acetate glue, based on my experiment, would only hasten the reaction.

I would try attacking the food source instead. Since acetate is food for geobacter, then try starving it out by soaking a specimen (one that isn't valuable - I'm not an expert!!!) in a baking soda solution for a few days, or even weeks. I haven't been able to find out - yet - what it is about the acetate that makes it a food source for this bacteria. Acetate, being acidic fruit matter that's fermented, might be made inedible by neutralizing the acid, but it may be the yeast content (so maybe salt would help??), or any number of other properties that provide geobacter energy to grow and multiply.

Sorry, I know this is a horrifying jumble of scientific ignorance mixed with wild conclusions, but maybe someone with a more solid grounding in the principles I've been playing with can find something useful in it. I grew up with a mother who taught Biology, so I tend to experiment with anything I'm curious about, but without much discipline I'm afraid. If any of this helps, then I'm glad, as my interest in fossils is new, and forums like this have been my best source of education and information.

[Gatorman]

Thanks for the information and welcome to the forum, I hope you'll stay and share with us what you learn and find.