Dad showed me this one some time ago, but here you go.
These things are eggs, petrified. You can see how the outer shell, breaks away in "onion" layers as for example, chicken eggs that get exposed to air and sun for some time - it fractures into layers.
That's the how you know knowledge. Dad says these are antediluvian dragon/serpent eggs - the big six foot diameter ones - to smaller hybrid animal forms. All chimera.
