<http://schema.org/alternativeHeadline>
"A flea that's been trapped in amber for 20 million years is carrying ancient bacteria, which scientists say could be the oldest evidence yet of a disease that has shaped human history."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/animals/blogs/flea-fossil-may-hold-ancestor-bubonic-plague>