<http://schema.org/mainEntityOfPage>
<http://www.upi.com/Top_News/US/2011/06/03/First-mastodon-skulls-in-Colo-unearthed/51161307131972/>
<http://www.upi.com/Top_News/US/2011/06/03/First-mastodon-skulls-in-Colo-unearthed/UPI-51161307131972/>