A dinosaur egg unearthed in Alabama in 1970 contains well-preserved and incredibly detailed remains of a nearly hatched dinosaur embryo.
The first dinosaur egg with an embryo ever found in the eastern United States is believed to come from a Lophorhothan, a duck-billed dinosaur that lived in the area now covered by modern-day Alabama. The embryo's leg bones are clearly visible, as is what appears to be fossilized yolk.
The 83-million-year-old egg was originally discovered by three high school students in 1970, but scientists at the time were unable to accurately determine its contents. James Lamb, a North Carolina State University graduate student, discovered the embryo after he borrowed the egg from Auburn University for a research project. While studying a part of the egg which previously had been cut away, he noticed three tiny bones. On a subsequent trip to Alabama, he arranged to have CT scans taken of the egg. The CT scans confirmed the embryo's presence and revealed the orientation of its bones.
An extraordinary set of circumstances allowed did the egg survive, since most dinosaur-age terrestrial deposits in the eastern United States have long since eroded. Lamb theorizes the egg was washed out to sea during an ancient hurricane. Eventually, the pores that supplied air to the embryo allowed sea water to fill the egg, and it sank, settling into chalk sediments on the ocean floor. Because chalk particles are so tiny, fossils preserved in them reveal much more delicate features than those preserved in grittier sediments. Chalk's alkalinity also helps buffer the fossils against destructive acids.
The egg is believed to be the only one in the world preserved in marine sediments.
In studying the egg, Lamb determined that its home was much like the Outer Banks of North Carolina and that carbon dioxide levels in its atmosphere would have been four times higher than current levels.
The he Auburn University Museum of Natural History currently houses the rare egg in a Styrofoam box marked “dino egg.” A more sophisticated and publicly accessible display is being planned.