Ancient eggshells crack open new truths about elephant birds, new CU Boulder study finds

• Although the elephant birds found in Madagascar's far north were closely related to those of the central area, the study shows their genetic makeup and diets were distinctly different.

Of note: Unlike most discoveries of this nature, this one was made without access to any skeletal remains, which have largely been lost in a hot and humid climate. Instead, it came from the shells of their 1,000-year-old eggs — which outsize footballs.

• Elephant bird eggshells are significantly thicker than any others. That better protects the DNA trapped inside and allows scientists to get a much clearer picture of how these creatures lived, from what they ate and drank to where they nested, and how.

Why it matters: "This opens up a field that nobody would have thought about before," paper co-author Gifford Miller said in a statement.

What's next: Researchers say the "pioneering achievement" will unlock new insights into the full diversity of birds that once inhabited Earth and why so many species have gone extinct.

• "There’s surprisingly a lot to discover from eggshell," said lead author Alicia Grealy, who conducted this research for her doctoral thesis at Curtin University in Australia.