Tortoise Egg

[TigerCreek]

I'm trying to determine how long it takes for something like this to happen to a tortoise egg. Years, decades, hundreds of years?

I found this Gopher Tortoise egg in the South Georgia/North Florida area.

It is about the size of a ping pong ball, heavy and solid.

It had been washed up in the rain and was found in soil that consists of a lot of sand, peat and clay.

The egg appears "fossilized" or "petrified" for lack of a better term.

The shell is firm and porcelain-like with a lot of scratches.

I candled the egg to show where the air sack appears to remain after staining itself into place and confirms it was an infertile egg.

I can share a video link I have of the egg if it would be helpful and allowed.

[digit]

Quite an interesting find.

 

Unfortunately, the odds of this being a fossilized tortoise egg are vanishingly small. The eggs of a Gopher Tortoise are indeed about ping-pong ball size but they have a paper thin shell to them and (of course) very liquid interior. Certain dinosaur eggs (with much thicker shells) have (under the right circumstances) been known to fossilize but these rarely have the preservation of a "fresh" egg and the fossilized shell is usually composed of small fragments still more or less in their proper position.

 

Having a tortoise egg fossilize perfectly smooth and round like the object shown above would be rare indeed. Much more likely is that it is an errant ceramic ball used in industry for crushing or making things into powders in what is called a ball mill. If you do an internet search for "alumina ball mill balls" you will see lots of images of alumina ceramic grinding balls of various sizes used for this purpose. These balls are created by pressing powdered alumina material together in a high pressure press (the way some pharmaceutical pills are created) before firing in a kiln to harden them. This results in a distinctive ring toward one side. During its use in a ball mill the rough edge would have worn away as the ball itself becomes polished to a more spherical shape. Your "candeling" may be showing this as an "air sack".

 

   

 

How a random ball mill ball would have ended up where you found it is indeed a mystery but much more probable of an occurrence than a miraculously preserved tortoise egg. The scraping marks on the surface would also seem to be consistent with its use in a ball mill. Still a very cool find and it would find a place in my display case as a real oddity (but industrial instead of biological).

 

Welcome to the forum! Lots of good information here and a bunch of friendly members eager to share information on their favorite obsession.

 

 

Cheers.

 

-Ken

 

Cheers.

[Fossildude19]

Welcome to the Forum.

 

Definitely a ceramic mill ball. 

People mistake them for egg fossils all the time. 

Keep looking.   

 

 

[TigerCreek]

Thanks for the replies. Never considered a mill ball.

The issue I have with it being a mill ball is the air pocket when candling. It's not a line but a pocket. This is the same view you have when candling an unfertilized egg. I would be curious to see what a mill ball of this size looks like when candled.

I have no interest in trying to make this something that it isn't, but I am curious to know how long and with what conditions would it take to transform an unfertilized egg into something like this?

[Fossildude19]

Technically speaking, anything over 10,000 years old and mineralized can be considered a fossil.

 

The thing to take into consideration is the area it was found.

Have eggs been found there before? 

Was this in the middle of nowhere, in the woods? Stream or river bank/bed? 

How could it have survived not being in stone matrix?

 

We have some egg guides,  HERE: 

 

Have a read through them. 

We get probably 4-5 egg posts here in a month. Sometimes more, sometimes less. 

Of those, maybe one per year is actually a fossil egg.

Sometimes, not even 1 is. 

I'd be willing to bet that if you cut this open with a tile saw, you would find it is totally ceramic. 

 

If you still have lingering doubts, please take the item to a local museum or university paleontologist, and have it looked at. 

We'd love to hear the outcome.   

 

 

 

[TigerCreek]

Thanks. I appreciate your time.

[digit]

1 minute ago, TigerCreek said:

but I am curious to know how long and with what conditions would it take to transform an unfertilized egg into something like this?

To transform a liquid filled egg into a solid fossil perfectly preserving the shape with no deflation, distortion or cracking of the surface you would need quite remarkable conditions.

 

Turtle/tortoise eggs are about 60% water and only about 3% minerals--the rest being proteins and lipids (fats/oils). So to fossilize (mineralize) an egg you need to bring it from 3% minerals to 100% minerals without distorting the shape. Infertile eggs which do not hatch but remain in the next soon break down. Once the shell is weakened due to microbial decay the inner liquids seep out and the egg deflates. A normal unhatched egg would likely disappear into the surrounding soil within a few months with little to no traces.

 

To become mineralized, the egg would have to be preserved in a high mineral content environment and be protected from microbial decomposition. These are the same long odds that all ancient biological materials overcome in order to become fossils. Quite often this involves a quick burial by sediments cutting off any chance of predation by larger carnivores/scavengers or smaller decomposers like insects/fungi. To keep microorganisms (like bacteria) from decomposing (rotting) the material, it helps to have an anoxic (deprived of oxygen) environment. Quite often for soft tissues this involves burying in sediments in hypoxic areas of sea water, fresh water, or ground water.

 

Bones are already mineralized and so their conversion to permineralized fossils is much easier. All that needs to happen is for the bones to be preserved from scavenging and erosion. Being buried in the sand of a river during a flash flood or encased in volcanic ash are two common ways in which articulated (or semi-articulated) animal skeletons are preserved as fossils. There were countless millions of dinosaurs (and countless more animals of all types) that have walked, crawled, slithered, and swam on this planet and only a tiny fraction have had the perfect conditions to preserve anything for us to find millions of years later.

 

To convert something as liquid as a tortoise egg to a solid mineral form and preserve its shape would require the very rapid infusion of minerals. It would be about as difficult as trying to fossilize a water balloon. You would need to have the egg buried in an anoxic environment (to protect it from predation or decomposition) and be able to very rapidly infuse it with minerals. The closest scenarios I can think of offhand that would even stand a slight chance of this type of preservation would be either being washed into a silty bay and buried in deep anoxic highly-mineralized sediments or possibly being buried by volcanic ash which then was wet enough to start dissolving the minerals so they could percolate into the egg.

 

It is difficult enough for bone to be preserved as a fossil and bones are a good portion mineral to start ~65% hydroxyapatite (calcium and phosphorous). This mineral lattice is enough to allow the collagen protein of the bone to decompose and be replaced with additional minerals to preserve the shape of the bone. The 3% mineral content of a tortoise egg is nowhere near enough to help it keep its shape while the other 97% is exchanged for minerals. The mineral rich waters in karstic cave systems that produces speleothems (stalactites and stalagmites) has been known to coat and mineralize objects fairly rapidly but other than by that extreme circumstance I cannot think of how a liquid filled egg could be mineralized rapidly enough to preserve its shape without the egg rotting and collapsing first.

 

43 minutes ago, TigerCreek said:

The issue I have with it being a mill ball is the air pocket when candling. It's not a line but a pocket. This is the same view you have when candling an unfertilized egg. I would be curious to see what a mill ball of this size looks like when candled.

There is a difference in color at the end but I'm not sure you can guarantee that this means it is hollow there. The fact that ball mill construction results in them having a discontinuity one one side similar in size to the lighter area you see while candling leads me to believe this is some artifact of the ball's production.

 

it would be great if you could figure out how to purchase an actual ceramic mill ball online for comparison. A quick search on the usual choices for online stores and auction sites did not turn up any cheap options. Having one to shine a light through would certainly satisfy any lingering doubts you might have but this is not the first mill ball that has turned up on this forum and I'm quite certain of its identity.

 

Still, a novel artifact--though too small to use on a billiard table.

 

 

Cheers.

 

-Ken

[TigerCreek]

Thank you for the very thorough explanation.

[digit]

The Fossil Forum is a repository of information. Knowledge expressed here may help you in the present but it also serves to educate those who may happen upon this conversation in the future as the result of some web searching for the curious egg-like object they've just discovered somewhere.

 

if you have an interest in fossils, check out the region specific section of the forum and see what others are finding in your state. You might even spot some members who live in your area. Fossil hunting with someone who can show you the ropes is a great way to get addicted started.

 

http://www.thefossilforum.com/index.php?/forum/99-georgia/

 

 

Cheers.

 

-Ken