Age of oldest rocks off by millions of years

Reading article, I couldn't find logic in this:

"They found that the half-life is just 68 million years, 30 per cent shorter than thought. That means that every rock dated by samarium-146 decay – which include some of the oldest on Earth and the moon, and even some Martian meteorites – formed 20 million to 80 million years earlier than thought."

There wasn't a link in the article but with the code at the end and searching, there is the original:

http://www.sciencemag.org/content/335/6076/1614.short

"Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with 146Sm-142Nd converge to a shorter time span and in general to earlier times, due to the combined effect of the new 146Sm half-life and (146Sm/144Sm)0 values."