Hatching a Mystery
From the sands of the Cretaceous Period to the hands of Mark Reinhold '98
Every day in his lab at James Madison University, paleoecologist Mark Reinhold '98 puts his hands on remnants of life that inhabited Earth at least 65 million years ago.
Eight dinosaur eggs.
Another JMU scientist determined that they originated in China or Mongolia.
"There are a number of dinosaur egg deposits in China and Mongolia," said Reinhold, "and they all date to the Cretaceous Period, about 65 million to 140 million years ago, when that area was desert."
"We know they're definitely eggs from their crystalline structure," he continued, "which we determined by examining shell fragments with a scanning electron microscope."
But dinosaur eggs?
"Their size makes it clear." (Ostriches didn't exist then, of course.)
Hoping to find traces of embryos within the dino eggs, Reinhold and his students boldly took them to where perhaps no dino eggs have gone before: the local hospital MRI room.
One by one, the eggs were placed in the space where a person's head would go in the MRI machine.
Although they found no embryonic or bone evidence, said Reinhold, "we did find iron concretions and fragments of shell at the base of the eggs.
"We didn't even know for sure that they had been hatched until we did the scans and found shell fragments at the bottom and breakage in the top of the shell within the sediment."
Now Reinhold and his students try to move from the general to the specific.
To find out what kind of dinosaur hatched from the eggs, they're doing thin sections, examining them with a polarizing microscope.
To recreate the environment the eggs hatched in, they're doing oxygen and carbon isotope analysis, which will indicate the temperature of the location where the eggs were laid, maybe the rock formation they came from, and possibly even what the parent dino ate for dinner. They're also looking for pollen in the sandstone on top of the eggs. Laboratory analysis could determine the age of the pollen, which would allow a closer estimate of the age of the eggs.
The beauty of the eggs now lies in the practical science they enable his students to do, said Reinhold.
"My students are as excited as I am," said Reinhold, who specializes in the study of mass extinction of species. "It'd be really handy if we could do a small-scale ecological reconstruction.
"I envision the parent approaching the nesting site, digging a nest into the sand. It's likely the parent didn't stick around after laying the eggs, because if she had, the shells would've been crushed into tiny pieces by nesting behavior after the babies hatched.
"After the baby dinosaurs crawled out, something happened. Possibly a sandstorm that further covered the eggs."
Reinhold and his students are thrilled to be doing the research on the dinosaur hatching. Millions of years later, the dinosaur eggs are spawning a brood of budding paleontologists.
Mark Reinhold '98 is a geology instructor at James Madison University. In his lab, he and his students work in the company of eight cantaloupe-sized, fossilized dinosaur eggs from 65 million to 140 million years ago. They're analyzing the eggs to determine their exact age, and thereby the species of dinosaur that laid them, and to recreate the ecological circumstances of their birth.