DNA retrieved from fossilized eggshells

A team of researchers from Australia and New Zealand universities have successfully extracted DNA from the fossilized eggshells of extinct birds. Don’t fear the devilish, door-opening cunning of the velociraptor quite yet. The oldest eggshell was from an emu that lived 19,000 years ago.

Fossilized elephant bird egg“We were able to obtain DNA from both thin (duck) and thick (elephant bird) eggshells, which suggests that thickness may not play a significant role in the recovery of DNA from eggshells,” lead author Charlotte Oskam told Discovery News.

“Furthermore, we were able to isolate DNA from eggshells from three countries, each with very different climate conditions,” added Oskam, a researcher at Murdoch University’s Ancient DNA Lab.

The 19,000 year-old emu eggshell was from Australia, as was an owl eggshell. They also got DNA from the fossilized eggshells of extinct moas and ducks from New Zealand and extinct elephant birds from Madagascar.

Fossilized moa eggshellsThe combination of calcium carbonate and a strong organix matrix in the eggshells decays very slowly. The strength of the structure protects the embryos from decay after the egg is laid, and keeps on protecting the eggshells long after the nest is empty.

Oskam explained that the “moa eggshell has 125 times lower microbial contamination when compared to moa bone. This highlights eggshells as an attractive substrate for ancient DNA work, especially whole genome studies.”

Successful DNA extraction isn’t going to lead to any cloned giant moas coming back, not this time anyway. Instead the research team is hoping the genetic information will fill out the evolutionary histories of these animals, and also be a useful non-invasive way of examining the genetic profiles of living animals.

Dinosaur eggs are still way off. Eggs that old (dinosaurs went extinct 65 million years ago) have become fully mineralized, so DNA extraction is so far impossible.

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