Says you... Here's what the Reuters article had to say:
Paleontologists forced to break the creature's massive thighbone to get it on a helicopter found not a solid piece of fossilized bone, but instead something looking a bit less like a rock.When they got it into a lab and chemically removed the hard minerals, they found what looked like blood vessels, bone cells and perhaps even blood cells.
"They are transparent, they are flexible," said Mary Higby Schweitzer of North Carolina State University and Montana State University, who conducted the study.
She said the vessels were flexible and in some cases their contents could be squeezed out.
"The microstructures that look like cells are preserved in every way," added Schweitzer, whose findings were published in the journal Science.
"Preservation of this extent, where you still have this flexibility and transparency, has never been seen in a dinosaur before." Feathers, hair and fossilized egg contents yes, but not truly soft tissue.
Studying the soft tissues may help answer many questions about dinosaurs. Were they cold-blooded like reptiles, warm-blooded like mammals, or somewhere in-between? How are they related to living animals?
"If we can isolate certain proteins, then perhaps we can address the issue of the physiology of the dinosaur," Schweitzer said.