From the BBC article you linked to in the OP :
Dr Schweitzer is not making any grand claims that these soft traces are the degraded remnants of the original material - only that they give that appearance.
"This may not be fossilisation as we know it, of large macrostructures, but fossilisation at a molecular level," commented Dr Matthew Collins, who studies ancient bio-molecules at York University, UK.
"My suspicion is this process has led to the reaction of more resistant molecules with the normal proteins and carbohydrates which make up these cellular structures, and replaced them, so that we have a very tough, resistant, very lipid-rich material - a polymer that would be very difficult to break down and characterise, but which has preserved the structure," he told the BBC.
It's early days yet, but I don't think this is going to shatter the foundations of evolutionary biology. It's just a rare and fascinating glimpse into a creature that lived millions of years ago.
I'm not a paleontologist (or any other kind of scientist), I just read the article you provided, so I could be wrong - but at least I did read the article

Confused ? You will be...