The fossil egg has a soft shell, shown in dark gray in the drawing (upper right), with arrows pointing to its folds and surrounding sediment shown as light gray. The cross section (lower left) shows that the egg consists mostly of a soft membrane surrounded by a very thin outer shell.

The fossil egg has a soft shell, shown in dark gray in the drawing (upper right), with arrows pointing to its folds and surrounding sediment shown as light gray. The cross section (lower left) shows that the egg consists mostly of a soft membrane surrounded by a very thin outer shell.