This story is in the news again, so I’ve reposted my description of the paper from 3½ years ago. This is an account of the discovery of soft organic tissue within a fossilized dinosaur bone; the thought at the time was that this could actually be preserved scraps of Tyrannosaurus flesh. There is now a good alternative explanation: this is an example of bacterial contamination producing a biofilm that has the appearance of animal connective tissue.
Read GrrlScientist’s explanation and Greg Laden’s commentary and Tara Smith’s summary of the recent PLoS paper that tests the idea that it is a biofilm.
Look! A scrap of soft tissue extracted from dinosaur bone:
It has been reported in Science this week that well-preserved soft tissues have been found deep within the bones of a T. rex, and also within some hadrosaur fossils. This is amazing stuff; fine structure has been known to be preserved to this level of detail before, but these specimens also show signs of retaining at least some of their organic composition. What the authors have done is to carefully dissolve away the mineral matrix of the bone, exposing delicate and still flexible scraps of tissue inside.