[alancalverd]

So, there's little point- other than a really good point.

Many coldblooded oviparous creatures bury their eggs rather than actively defend them, so rotation isn't always required.

Apropos chickens

When force is applied evenly, an average of 53 pounds of force is required to crack an egg when it is standing up on its end. It takes 90 pounds of force to crack an egg on its side in the same circumstances.
The amount of force required to crack the egg depends on the surface of the egg over which the force is applied. The shape of the egg naturally helps to distribute force across the surface, making it much more difficult to break. When an egg is cracked on the side of a pan or another edge, the force is concentrated over a relatively small surface area, so it can be cracked with less force.

That's one hell of a chicken, standing on one leg! My money is on a soft, fat dinosaur (yes, I've lost money on horses) incubating a clutch of eggs.

[Deecart]

When force is applied evenly, an average of 53 pounds of force is required to crack an egg when it is standing up on its end. It takes 90 pounds of force to crack an egg on its side in the same circumstances.

I dont agree with these results.
I suppose they came from this experience : https://www.admet.com/egg-compression-strength-test-2/

But if you look carefully, you will see that the egg explode soon the weight is in contact with the shell.
This is obvious with the test with the egg pointing upward.

The problem here is : The foam used is not adequate.
1. It doesent distribute accurately the weight.
2. When compression is strong (like it is the case here), it dosent act any more to distribute the weight on the surface of the egg and the compression occur at a very tiny surface (so it breaks instantly).

This experience demonstrate the limit where the foam remain elastic, not the limit where the egg break (so for the egg pointing upward, but the weight with the egg lying horizontaly do not exceed this foam limit).

Other experiments have been done like this one :

The egg is cushioned by a hemispherical cap made of Sorbothane, one above and one below (see photo). Lead bricks are added, one at a time, on top of the egg. Each lead brick weighs 25 lbs and one egg supported 10 bricks! Yes, you could just stand on the egg without breaking it.

https://sciencedemonstrations.fas.harvard.edu/presentations/egg-shell-strength

Here they use sorbothane instead of the poor foam of the previous experiment.
The conclusion is : When pointed upward, the egg support 250 pounds so around 110 Kg.
I suppose that when disposed horizontaly the egg do not resist so much, perhaps around 50 pounds so around 25 Kg like the previous experiment showed.

[Deecart]

Concerning thoses dinosaur birds, perhaps their eggs dident break because they were not solid at all, like those of the snakes.

We can say : Lets make the egg ticcker, but making the egg thicker has some disavantage.
Oxygen can not diffuse so well.
The nestling need to break the egg.

[Petrochemicals]

The chicken eggs, altougth it is already very robust, break if you put, let say 4 chicken on it.
Even better if the "object" put on it is solid (like could be the skin of dinosaurs), so there is no distribution of the weight.
The exeption (it is much more robust) is when the egg is pointed upward, but this is unlikely to occur in nature.

Chicken eggs crack best when a knife is put across it, similarly to glass cracking in a fracture like pattern because of a small pressure point. If the contact is spread it bears greater weight. Also chickens do not sit on eggs but sit with them around their breast feather, sort of leaning toward them.

[Deecart]

Also chickens do not sit on eggs but sit with them around their breast feather, sort of leaning toward them.

Yes, i have actually a turtle dove with 4 eggs and this is how she does (she has also some special feathers on the breasts that help surrounding the eggs).
She sometime walk on the eggs by accident but they remain intact.
The question of having strong eggs is not because they "sit on it" but because they must be strong enought to resist the weight of the bird when they do some movement.

[alancalverd]

There is plenty of evidence than an ostrich egg (shell thickness about 1.5 mm) can support a human. Not sure how big a dino egg was but it's pretty clear that 100 kg per egg is well within the structural capabilities of a viable egg.

[Deecart]

There is plenty of evidence than an ostrich egg (shell thickness about 1.5 mm) can support a human. Not sure how big a dino egg was but it's pretty clear that 100 kg per egg is well within the structural capabilities of a viable egg.

Yes, this kind of egg surely resist 100kg and much more safely.

The dominant ostrich couple (male and female) are taking care of the eggs of their own and of the eggs of the group.. In this way they can brood the nest in turn and the eggs are protected by the most dangerous parents within the group.
When the eggs become hatchlings, the one who take care of them is the dominant one, the male dominant.
The ostrich can easyly kill any predator with his 400kg propulsed "claws" (altought he is not very clever and some clever animals like lions can trick him).
For the ostrich, "an egg is not an egg" (they are able to recognize their own !), but finaly all the hatchlings who survived are his children.

The female common ostrich lays her fertilized eggs in a single communal nest, a simple pit, 30 to 60 cm (12–24 in) deep and 3 m (9.8 ft) wide,[1] scraped in the ground by the male.

The dominant female lays her eggs first, and when it is time to cover them for incubation she discards extra eggs from the weaker females, leaving about 20 in most cases.[2]

A female common ostrich can distinguish her own eggs from the others in a communal nest.[3]

 Ostrich eggs are the largest of all eggs,[4] though they are actually the smallest eggs relative to the size of the adult bird — on average they are 15 cm (5.9 in) long, 13 cm (5.1 in) wide, and weigh 1.4 kilograms (3.1 lb), over 20 times the weight of a chicken's egg and only 1 to 4% the size of the female.[5] They are glossy cream-colored, with thick shells marked by small pits.[6]

The eggs are incubated by the females by day and by the males by night. This uses the coloration of the two sexes to escape detection of the nest, as the drab female blends in with the sand, while the black male is nearly undetectable in the night.[6] The incubation period is 35 to 45 days, which is rather short compared to other ratites. This is believed to be the case due to the high rate of predation.[5] Typically, the male defends the hatchlings and teaches them to feed, although males and females cooperate in rearing chicks. Fewer than 10% of nests survive the 9 week period of laying and incubation, and of the surviving chicks, only 15% of those survive to 1 year of age.[7]

https://en.wikipedia.org/wiki/Ostrich_egg







 

[micheal2008]

of course. The answer is the egg.

[paul cotter]

It's a very simple matter actually: the egg gave rise to the chicken, the egg having been purchased at the local  supermarket. Q E D, as Euclid would have said.

[Colin2B]

of course. The answer is the egg.

The egg of what?

[Zer0]

the cock Came first...Period!

P.S. - 🐓

[micheal2008]

Of course the egg came first. Chickens and ducks, can lay eggs without sperm.