Dinosaur egg size (usually not much longer than a centimeter or two) and lack of an eggshell with its typical anatomy. Stones: The erosive effects of water can sometimes round rocks into egg-like shapes. Paleontologists' knowledge of the structure of dinosaur eggs is limited to the hard shell. However, it can be inferred that dinosaur eggs had an amnion, chorion, and an allantois, the three major membranes in modern bird and reptile eggs. Dinosaur eggs vary greatly in size and shape, but even the largest dinosaur eggs ("Megaloolithus") are smaller than the largest known bird eggs, which were laid by the extinct
Specimens of Archaeopteryx 1998, Vieser 1988). The Eichstätt specimen of "Archaeopteryx" is represented by an almost-complete skeleton visible on both slab and counter-slab, though the majority of the skeleton is on the main (overlying) slab. The animal is preserved lying on its right side, as in the Berlin specimen. The specimen is in almost complete articulation with many items in their original positions. The vertebral column, which had become strongly recurved in death, enabled the animal's head to lie above the pelvis in near-perfect preservation. This excellently-preserved skull is one of the most notable features of this specimen. The majority of the Eichstätt