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List of Ways Fossils are Preserved


BobWill

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I an putting together some hand-outs for the Dallas Paleontological Society table to use at local events. We are committed to educating the public about the science of paleontology. Below is one proposed list that I have put together from different sources and re-worded to fit in a small space. Some of you may find mistakes or other things to add or even a better way to explain something. I would appreciate any help you can offer. Anyone should feel free to use this in any way you like. Any other material you think would make a good hand out would be appreciated. We have a nice deep time chart and a hand-out on age-dating fossils as well as diagrams of local strata. Thanks.

 

            20  WAYS  FOSSILS  CAN  BE  FORMED

                                             DUPLICATION

1    Internal Mold  (sediment in contact with inner surface solidifies then original dissolves)

2    External Mold  (sediment in contact with outer surface solidifies then original dissolves)

3    External Cast   (original outer surface dissolves and space fills with solidifying material)

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

                                            

                                           MINERALIZATION

5    Permineralization    (space between cells fills with minerals that solidify)

6    Petrification    (space between cells fills with silica binding to cellulose)

7    Repalcement    (cells replaced with new minerals that solidify)

8    Recrystallizaion    (replacement when the new minerals are a crystal form)

                                              

                                              TRACE FOSSIL

9     Tracks

10   Infilled Burrows

11   Coprolites   (animal droppings)

12   Feeding Traces

13   Urolite   (urine splatters)

14   Regurgitants   (animal vomit)                         

                                              

                                                DESSICATION

15   Peat Pit

16   Tar Pit

17   Frozen Tundra

                                                     

                                                     OTHERS

18   Compression   (thin carbon film formed by chemical change under pressure)

19   Resin Inclusion   (Life trapped in resin which hardens into amber or copal)

20   Bioimmuration   (impression formed on a shell by growing over another life form)

 

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Congratulations Bob for defining the term “internal cast” correctly:

“4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)”

 

Remember an internal cast is not an internal mold or a steinkern. The inner surface of a bivalve replaced by pyrite is an internal cast.

 

Point out that you are teaching taphonomy.

 

Add another type(s) of desiccation preservation sometimes called mummification.  Fossil sloth dung is found in the Grand Canyon. Dry conditions preserved the matter. Also, mummified wood was found next to Canadian diamond pipes. 

 

https://www.google.com/amp/s/www.livescience.com/amp/23374-fossil-forest-redwood-diamond-mine.html

 

Coalification might also be a distinct type of preservation. 

 

 

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My goal is to leave no stone or fossil unturned.   

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2 hours ago, DPS Ammonite said:

Point out that you are teaching taphonomy.

Add another type(s) of desiccation preservation sometimes called mummification.  Fossil sloth dung is found in the Grand Canyon. Dry conditions preserved the matter. Also, mummified wood was found next to Canadian diamond pipes. 

Coalification might also be a distinct type of preservation. 

 

 

Thanks John,

I had mummification on the original list but took it off because I didn't know about those two examples and I didn't want to start the classic "how old does it have to be to call it a fossil" debate ;) I will put it back.

I had no idea coalification was different from compression but I see where it just happens slower so I will add it too. I hope they still fit on one page.

I knew you guys would have some ideas,thanks again.

 

 

 

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If that is the actual wording of the print-out, you need to fix the spelling of #7 "replacement" and #8 "recrystalization."

 

Would a gastrolith be categorized as a feeding trace?

 

My least favorite fossil type would have to be the urine splatter partly because I don't think I could find a stand for that.

 

I wonder if anyone has found a sabercat (or any fossil cat) hairball or a fossil owl pellet.

 

Jess

 

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20 hours ago, siteseer said:

If that is the actual wording of the print-out, you need to fix the spelling of #7 "replacement" and #8 "recrystalization."

 

Would a gastrolith be categorized as a feeding trace?

 

My least favorite fossil type would have to be the urine splatter partly because I don't think I could find a stand for that.

 

I wonder if anyone has found a sabercat (or any fossil cat) hairball or a fossil owl pellet.

 

Jess

 

Thanks for the correction Jess. I'll wait to hear opinions on including gastroliths before I add it. Otherwise here is the list with John's suggestions added and spelling corrected. As written it fits well on a single page for printing.

 

             22  WAYS  FOSSILS  CAN  BE  FORMED

                                             DUPLICATION

1    Internal Mold  (sediment in contact with inner surface solidifies then original dissolves)

2    External Mold  (sediment in contact with outer surface solidifies then original dissolves)

3    External Cast   (original outer surface dissolves and space fills with solidifying material)

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

                                            

                                           MINERALIZATION

5    Permineralization    (space between cells fills with minerals that solidify)

6    Petrification    (space between cells fills with silica binding to cellulose)

7    Replacement    (cells replaced with new minerals that solidify)

8    Recrystalizaion    (replacement when the new minerals are a crystal form)

                                              

                                              TRACE FOSSILS

9     Tracks

10   Infilled Burrows

11   Coprolites   (animal droppings)

12   Feeding Traces

13   Urolite   (urine splatters)

14   Regurgitants   (animal vomit)                         

                                               

                                                DESSICATION

15   Peat Pit

16   Tar Pit

17   Frozen Tundra

18   Mummification

                                                     OTHERS

19   Compression or Carbonization  (thin carbon film formed by chemical change)

20   Coalification    (compression occurring by much slower processes)

21   Resin Inclusion   (Life trapped in resin which hardens into amber or copal)

22   Bioimmuration   (impression formed on a shell by growing over another life form)

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I'm not so sure about including gastroliths, since, although they are leftovers, so to speak, I think that they aren't generally any further "fossilized" than when they were swallowed, although I'm not 100% sure about that.

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Greetings from the Lake of Constance. Roger

http://www.steinkern.de/

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As gastroliths are just stones that have been swallowed I don’t know if they qualify as fossilized....

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3 hours ago, Ludwigia said:

I'm not so sure about including gastroliths, since, although they are leftovers, so to speak, I think that they aren't generally any further "fossilized" than when they were swallowed, although I'm not 100% sure about that.

Gastroliths are trace fossils. A stone is transformed into a fossil when it is shaped while inside the animal. Similarly a layer of mud is transformed into a trace fossil when a dinosaur steps on it and the mud later turns into a mudstone with a print.

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3 hours ago, DPS Ammonite said:

Gastroliths are trace fossils. A stone is transformed into a fossil when it is shaped while inside the animal. Similarly a layer of mud is transformed into a trace fossil when a dinosaur steps on it and the mud later turns into a mudstone with a print.

It occurred to me that they are also collected and displayed like other fossils.  Since the animal had an impact on the stone It seems right that it might be considered a fossil even though nothing is "fossilized."  John, have you seen a reference in a paper or textbook calling them fossils or declaring they should be considered trace fossils?

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“Both coprolites and gastroliths are trace fossils. These fossil types deal with the behavior of the organism from which they came rather than the actual organism itself.”

 

https://ucmp.berkeley.edu/paleo/fossils/coprol.html

 

Gastroliths are digestichnia according to this article:

 

https://www.researchgate.net/publication/259558334_Digestichnia_Vialov_1972_-_An_almost_forgotten_ethological_class_for_trace_fossils

 

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My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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15 hours ago, DPS Ammonite said:

“Both coprolites and gastroliths are trace fossils. These fossil types deal with the behavior of the organism from which they came rather than the actual organism itself.”

 

https://ucmp.berkeley.edu/paleo/fossils/coprol.html

 

Gastroliths are digestichnia according to this article:

 

https://www.researchgate.net/publication/259558334_Digestichnia_Vialov_1972_-_An_almost_forgotten_ethological_class_for_trace_fossils

 

Thanks for the links. I just looked on wikipedia and see where I could include, rests, termite mounds and even stromatolites as well. Since this is getting so involved I may include trace fossils under "others" followed by a list. I have added the new list below. I may have coined a new phrase. I hope no one minds, "bio-sedimentological structures."

 

             17  WAYS  FOSSILS  CAN  BE  FORMED

 

                                             DUPLICATION

 

1    Internal Mold  (minerals in contact with inner surface solidify then original dissolves)

 

2    External Mold  (sediment in contact with outer surface solidifies then original dissolves)

 

3    External Cast   (original outer surface dissolves and space fills with solidifying material)

 

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

 

                                            

 

                                           MINERALIZATION

 

5    Permineralization    (space between cells fills with minerals that solidify)

 

6    Petrification    (space between cells fills with silica binding to cellulose)

 

7    Replacement    (cells replaced with new minerals that solidify)

 

8    Recrystallization    (replacement when the new minerals are a crystal form)

 

                                                                     

 

                                               DESSICATION

 

9   Peat Pit

 

10   Tar Pit

 

11   Frozen Tundra

 

12   Mummification

 

                                                     

 

                                                    OTHERS

 

13   Compression or Carbonization  (thin carbon film formed by chemical change)

 

14   Coalification    (compression occurring by much slower processes)

 

15   Resin Inclusion   (Life trapped in resin which hardens into amber or copal)

 

16   Bioimmuration   (impression formed on a shell by growing over another life form)

 

17   Ichnofossils or Trace Fossils    ( tracks, infilled burrows, coprolites or droppings, feeding         

 

                                                              traces, urolites or urine splatters, regurgitants or vomit,

 

                                                              rests, gastroliths, termite mounds, bite marks, and bio-sedimentological

 

                                                              structures like stromatilites)

 

 

 

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It just occurred to me that in the first item "internal mold" the material inside a shell would not really be sediment but rather minerals seeping in after burial. I changed it  in the last iteration posted. If that's wrong I'll change it back.

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7 hours ago, DPS Ammonite said:

Gastroliths are trace fossils. A stone is transformed into a fossil when it is shaped while inside the animal. Similarly a layer of mud is transformed into a trace fossil when a dinosaur steps on it and the mud later turns into a mudstone with a print.

 

Yes, under the definition I've always gone by, a fossil is not only the remains of an ancient organism but also any evidence of activity of an organism.  A gastrolith is shaped by the digestive system of an organism in an observable way.  

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3 hours ago, BobWill said:

Thanks for the links. I just looked on wikipedia and see where I could include, rests, termite mounds and even stromatolites as well. Since this is getting so involved I may include trace fossils under "others" followed by a list. I have added the new list below. I may have coined a new phrase. I hope no one minds, "bio-sedimentological structures."

 

             17  WAYS  FOSSILS  CAN  BE  FORMED

 

                                             DUPLICATION

 

1    Internal Mold  (minerals in contact with inner surface solidify then original dissolves)

 

2    External Mold  (sediment in contact with outer surface solidifies then original dissolves)

 

3    External Cast   (original outer surface dissolves and space fills with solidifying material)

 

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

 

                                            

 

                                           MINERALIZATION

 

5    Permineralization    (space between cells fills with minerals that solidify)

 

6    Petrification    (space between cells fills with silica binding to cellulose)

 

7    Replacement    (cells replaced with new minerals that solidify)

 

8    Recrystalizaion    (replacement when the new minerals are a crystal form)

 

                                                                     

 

                                               DESSICATION

 

9   Peat Pit

 

10   Tar Pit

 

11   Frozen Tundra

 

12   Mummification

 

                                                     

 

                                                    OTHERS

 

13   Compression or Carbonization  (thin carbon film formed by chemical change)

 

14   Coalification    (compression occurring by much slower processes)

 

15   Resin Inclusion   (Life trapped in resin which hardens into amber or copal)

 

16   Bioimmuration   (impression formed on a shell by growing over another life form)

 

17   Ichnofossils or Trace Fossils    ( tracks, infilled burrows, coprolites or droppings, feeding         

 

                                                              traces, urolites or urine splatters, regurgitants or vomit,

 

                                                              rests, gastroliths, termite mounds and bio-sedimentological

 

                                                              structures like stramotilites)

 

 

 

 

 

I see "recrystallization" got misspelled again.  It has two l's and a t in there.  "Stromatolites" is also misspelled at the bottom.

 

 

 

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1 hour ago, siteseer said:

 

 

I see "recrystallization" got misspelled again.  It has two l's and a t in there.  "Stromatolites" is also misspelled at the bottom.

 

 

 

Thanks Jess. Corrections made, again...

Any opinion on bite marks?

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4 minutes ago, BobWill said:

Thanks Jess. Corrections made, again...

Any opinion on bite marks?

 

Oh yeah, bite marks are evidence of activity and they tend to be found on other fossils but I also have an impression of a xenacanth tooth from the late Carboniferous of Ohio (the Linton site).  The tooth either floated or rotted away but left an identifiable impression in sediment.

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1 hour ago, siteseer said:

 

Oh yeah, bite marks are evidence of activity and they tend to be found on other fossils but I also have an impression of a xenacanth tooth from the late Carboniferous of Ohio (the Linton site).  The tooth either floated or rotted away but left an identifiable impression in sediment.

Would the impression in sediment be considered an external mold rather than an ichnofossil? I suppose the answer to that may depend on whether it rotted away after being enclosed in the sediment or washed away beforehand. I have also heard the argument that an external mold is a trace fossil even though an internal mold is not. Including them with the other three duplication fossils does give them more continuity in a way.

I don't know if I should exclude a bite mark on another fossil because it is on the fossil. We have examples of fossil-on-fossil with bioimmuration  and oysters attaching themselves to other shells etc. but I don't see bite marks on the list of ichnofossils on the wiki-page. Maybe @DPS Ammonite has seen a paper on that too. I suppose they could also just be considered another form of feeding trace.

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The tooth impression is an external mold. 

 

Ichnofossils show movement from a behavior of an organism. Molds are formed from dead organisms. As an example, an impression of a resting live starfish is a resting trace fossil. An impression of a dead starfish (usually much more detailed than a resting trace) that did not move is an external mold. 

 

A bite mark is a trace fossil. The best way to search for literature on trace fossils is to search for “x trace fossil” where x could be “bite mark”.

See the article and referenced paper on bite marks:

 

https://blogs.scientificamerican.com/laelaps/bitten-bone-a-sign-of-a-cretaceous-snack/

 

Don't limit yourself to lists of trace fossils on Wikipedia. There are good papers on trace fossils by Seilacher, Bromley and others. See this website for general references:

 

http://www.sjvgeology.org/geology/trace_fossils_references.html

 

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My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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Final (for now) version with 27 ways instead of 17 so it sounds more impressive. I reduced the font size to make them all fit on one page better. Thanks to everyone for all the help. Feel free to use this any way you like.

 

                     27  WAYS  FOSSILS  CAN  BE  FORMED

 

                                          DUPLICATION

 

1    Internal Mold  (minerals in contact with inner surface solidifiy then original dissolves)

 

2    External Mold  (sediment in contact with outer surface solidifies then original dissolves)

 

3    External Cast   (original outer surface dissolves and space fills with solidifying material)

 

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

 

                                       

 

                                        MINERALIZATION

 

5    Permineralization    (space between cells fills with minerals that solidify)

 

6    Petrification    (space between cells fills with silica binding to cellulose)

 

7    Replacement    (cells replaced with new minerals that solidify)

 

8    Recrystallization    (replacement when the new minerals are a crystal form)

 

                                            

 

                                            DESSICATION

 

9     Peat Pit

 

10   Tar Pit

 

11   Frozen Tundra

 

12   Mummification

 

                                             

 

                                      ICHNOFOSSILS OR TRACE FOSSILS

 

13   Tracks

 

14    Infilled burrows

 

15    Coprolites or droppings

 

16    Feeding traces

 

17    Urolites or urine splatters

 

18    Regurgitants or vomit

 

19    Body rests

 

20    Gastroliths

 

21    Bite marks

 

22    Bio-sedimentological structures like stromatolites

 

23    Termite mounds

 

                                                     

 

                                                OTHERS

 

24   Compression or Carbonization  (thin carbon film formed by chemical change)

 

25   Coalification    (carbonization occurring by much slower processes)

 

26   Resin Inclusion   (Life trapped in resin which hardens into amber or copal)

 

27   Bioimmuration   (impression formed on a shell by growing over another life form)

 

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  • 2 months later...
On 12/11/2019 at 12:57 AM, doushantuo said:

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I am just now getting around to adding this to my list and will call it  " Condensed Phosphroite Pseudo-Steinkerns" unless someone can suggest a better name. While I'm adding items it occurred to me that I may also need to add hardened resin in addition to resin inclusions if it would be considered a fossil. If so, should it go under trace fossils since it's something the actual living thing left behind like a coprolite and is there a general term better than hardened resin besides just amber & copal?

These two would make a nice round 30 items for the list. If I should add them I will post the new list, hopefully with all those creeping mistakes corrected.

 

edit: I forgot to mention I have also added   "Adpression   -  (compression-impression)"  from the Wikipedia page on fossilization which apparently is not the same as carbonization like I thought.

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3    External Cast   (original outer surface dissolves and space fills with solidifying material)

 

4    Internal Cast    (original inner surface dissolves and space fills with solidifying material)

 

I'm not sure how I missed this thread, but I'd like to point out that there is no real difference between 3 & 4 in the common case of bivalves:  In either case, the result is an external cast.  "Surface" is a weak descriptor for containment wall, partition, or barrier.  But, the simplest way to correct the problem is to invert the sequence in "4  Internal Cast" to something like:

 

"(space fills with solidifying material and then the original containment wall dissolves)"

 

Just trying to help.

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http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

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