The paper is not available yet - from the article: 'The group's findings, to be published this week in the Proceedings of the National Academy of Sciences.'
So where did Ms. Ross-Flanigan obtain the information? From University of Michigan paleontologist William J. Sanders - she quotes him in the story. Specifically she wrote:
The dating of the new fossil, discovered in the East African country of Eritrea, also pushes the origins of elephants and mastodons five million years farther into the past than previous records, Sanders said.
I am perfectly aware that the paper has not been published yet. That's why I was confident you had not read it.
As for the statement: reporters put quote marks around direct quotes. As best that was the reporter's understanding of what the scientist sid.