Raptor

[smoovevirgo]

I posted this a couple,days ago but I don't see it anymore so here it is again with an article on oviraptorid eggs. It's exactly the same.

[LordTrilobite]

I'm sorry but that is just a rock. It lacks an eggshell, which is what one would expect from a real egg. It also lacks the fine structure.

[Rockwood]

Agreed. Similar, but not exact.

[CraigHyatt]

Take it to a museum or university. They will tell you it's not an egg.

[Ludwigia]

The title of this thread is misleading.

[Rockwood]

The title of this thread is misleading.

Fittingly so.https://en.wikipedia.org/wiki/Oviraptor

[doushantuo]

All amniote eggs show porosity* and spherulitic structure.**

*fluid and gas exchange for the embryo.

**these distinct structures are the consequence of the presence of a Membrana Testacea

Now,you have to realize,fossil eggs are a rarity.We have daily experience with the fragility of galliform ("chicken")eggs,don't we?Never put them on the bottom of your shopping bag.

So you have to realize what an isolated egg means,taphonomically and ethologically.

Amniotes(those vertebrates that surround the embryon with allantois and chorion)lay eggs in clutches.

A lot of fossil eggs are found in nesting structures,and not as single items.

Also,if you're scouting a site,how likely is it that a macrofossil egg is overlooked by other collectors?.If it is STILL there it might be likely that other collectors had picked it up ,and had come to the conclusion it was NOT

an egg.****

If anyone is interested:it is still very uncertain why eggs have the shape they have(oval,elliptical,spherical AND pyriform).The egg obviously experiences stress in the oviduct.If this were NOT the case,most eggs would be elliptical and not oval.

More fun facts(i sound like Sheldon from BBT):rubbery eggs exist(laid by lepidosaurs),incompletely mineralized eggs,and moulting influences clutch size.

Monotremate("platypus") eggs,BTW,are NOT homologous with reptile/avian /fish/amphibian eggs

*** or,less parsimonious: that most collectors are myopic

Edited August 15, 2016 by doushantuo

[fifbrindacier]

Once again, i agree with the others, it is a rock. Maybe a moraine rock. The fractures you see are the result of the compression it sustained, the shocks when it was rolled down, the erosion. It has a suggestive color and shape that also make it look like a potato.

Human's mind, sight, senses and capacities of analysis are located in the brain closed in a skull. I have a friend that often compare that skull and the brain inside with a can that you can open to free its content. You have in you all the resources to open your can to other shapes than eggy and to fossils.

[Troodon]

The egg in the picture has EGGSHELL on it, why is it so difficult to see? Point out the shell in your picture, it's smooth as baby's butt. You continue to show us stones that just look like eggs but the world and universe is full of those type of shapes.

That museum article says the following:

Genuine fossil eggs usually have an easily identifiable shell which differs significantly from the enclosed sediments either by having a fine surface ornamentation (the smoother the "shell," the less likely it is to be a non-bird dinosaur egg) or a specific type of crystalline structure in cross-section. Also, because eggshell tends to be brittle, the shell is almost always heavily cracked with clear shifting of the eggshell

[doushantuo]

I think i've pointed several times to the writings of Hirsch ,Sabath**,and Mikhailovksi**.

**in the SAME issue of APP,no less .

Edited August 15, 2016 by doushantuo

[fifbrindacier]

All amniote eggs show porosity* and spherulitic structure.**

*fluid and gas exchange for the embryo.

**these distinct structures are the consequence of the presence of a Membrana Testacea

Now,you have to realize,fossil eggs are a rarity.We have daily experience with the fragility of galliform ("chicken")eggs,don't we?Never put them on the bottom of your shopping bag.

So you have to realize what an isoleted egg means,taphonomically and ethologically.

Amniotes(those vertebrates that surround the embryon with allantois and chorion)lay eggs in clutches.

A lot of fossil eggs are found in nesting structures,and not as single items.

Also,if you're scouting a site,how likely is it that a macrofossil egg is overlooked by other collectors?.If it is STILL there it might be likely that other collectors had picked it up ,and had come to the conclusion it was NOT

an egg.****

If anyone is interested:it is still very uncertain why eggs have the shape they have(oval,elliptical,sperical AND pyriform).The egg obviously experiences stress in the oviduct.If this were NOT the case,most eggs would be elliptical and not oval.

More fun facts(i sound like Sheldon from BBT):rubbery eggs exist(laid by lepidosaurs),incompletely mineralized eggs,and moulting influences clutch size.

Monotremate("platypus") eggs,BTW,are NOT homologous with reptile/avian /fish/amphibian eggs

*** or,less parsimonious: that most collectors are myopic

I am myopic !

I think they have those shapes to avoid robbery (not rubbery ) or to take the less space possible for the parents to sit on, or maybe it is because those shapes are the most efficient ones to keep the heat inside. Maybe it also is because of the centrifuge strenght and the flexibility of their shell.

[doushantuo]

Topologically speaking:oval egs take up the least space in a roundish nest.There are mathematical models to prove that

You don't want to know about my eyesight,Fif.I've got contact lenses the size and thickness of pepsi bottles

Edited August 15, 2016 by doushantuo

[fifbrindacier]

Also, because eggshell tends to be brittle, the shell is almost always heavily cracked with clear shifting of the eggshell

Like when you crush a cooked egg.

[tmaier]

The devil is in the details.

Search for the devil. :0

Edited August 15, 2016 by tmaier

[doushantuo]

eggs are a strength/porosity compromise.The embryon has got to exchange fluids and gases with it's surroundings,but the egg has to survive transport,and being laid,which is sometimes being done on a tough surface/

substrate.

It seems ,funnily enought ,that invertebrate predation is more of a problem than macrovertebrate predation

Edited August 15, 2016 by doushantuo

[fifbrindacier]

Topologically speaking:oval egs take up the least space in a roundish nest.There are mathematical models to prove that

You don't want to know about my eyesight,Fif.I've got contact lenses the size and thickness of pepsi bottles

And, do you have pepsi bottles ?