Today, at home in Leicester, England, Terry Manning's laboratory beakers may be simple plastic bowls, but they hold precious clues to the family or genus of a dinosaur. Not all fossil eggs contain embryos. Eggs were often crushed by the mother, siblings, or even intruders, and the insides drained out. If eggs were perhaps only cracked, then rapidly buried before they rotted or decomposed, groundwater solutions bearing calcite (which fossilizes animals) could enter the shell and eventually surround the bones and tissues with stone. As Manning puts it, “the animal is perfectly packaged in calcite.”
Manning's method is perhaps his madness. He uses a painstaking process that etches away only 1/2000 of an inch of surrounding rock and fossilized eggshell a day! His secret solution of acid gradually uncovers the animal hidden within. “When I find eggs with similar features, I think about how best to prepare them to show the embryo,” he points out. “We used mechanical methods in some early experiments, but I finally adapted known chemical methods. To date, I have on hold many eggs with bones, but I haven't had time to solve the problems they present.”
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