<http://schema.org/alternativeHeadline>
"The flightless bird is thought to have gone extinct by 1662, but one geologist has discovered observations that may challenge that extinction date."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/animals/stories/debating-the-dodo-extinction-date-challenged-by-journals>