Robert Farrar sent in this link – which begins in 2005 and the discovery by Mary Sweitzer of fossilised soft tissue in a Tyrannosaurius skeleton from the Late Cretaceous era – see http://blog.drwile.com?p=11753
It is not unusual for soft tissue to be found in a fossilised condition, such as in the remains of mammoth in the Arctic permafrost, or preserved in amber, but not in a beastie as big as our pal Tyrannosaurus Rex. Hence, the discovery was met with disbelief, and explanations to suggest otherwise were quickly let out of the box, which may or may not have been true. Sweitzer, on the back end of a lot of criticism obviously sought to find a way of absolving her theory – and set in motion an experiment (described in the link above). She had what looked a lot like blood vessels on what is elsewhere described as a concretion but which Sweitzer had suggested was the heart of a dinosaur. Iron embedded in the blood vessels (or lines in the concretion) were thought to be derived from haemoglobin, a blood protein. When the dinosaur died, she suggested, the blood decayed reducing the iron and allowing it to mix with the soft tissue of the heart itself. Proteins are long chains of amino acids and it is possible iron in reaction with oxygen caused the polymers to cross-link – and in that situation they could have resisted the decay factor (although this would only have been part of the scenario, we might imagine). Swietzer's team tested this hypothesis by using ostrich blood vessels – and soaking them in various liquids. It turned out most of them hastened the decay apart from the sample soaked in blood – whcih survived for 2 years. Sweitzer did not simulate rapid burial in sediments so the experiment is of limited usefulness.
A different view is to be had at http://content.usatoday.com/communities/sciencefair/post/2011/01/dinosau… … where a scan was used on the fossil heart and concluded it was hardened sand that had washed down the gullet of the dead beast – presumably as it was buried in the sediment.It is also described as a three dimensional iron cemented structure found in the interior thoracic cavity of the dinosaur. It was examined with high radiation tomography as well as by scanning electron mircroscopy. It seems it was not a heart after all but a concretion of sand (in the gullet, it is suggested). However, the scientists added, 'we really don't know how concretions form – but we do know their shape and chemistry vary.' The object appears to be a mixture of sand grains and iron of some kind and is extremely hard. Concretions appear to form around decaying organic material – flint is another example of silica forming around something like a sponge or other marine life form, with sand subsequently filling the spaces where the soft tissue had rotted away. This would have happened after burial in the sediment (which may have included a lot of sand and silt). However, the fact remains that it still resembles a heart – even though mainstream has found a way of car parking the problem.