Updated: July, 2014, July 2008, Nov. 2006
Many young earth creationists (YECs) assert that because apparent blood cells and other "soft tissues" have been found in some dinosaur fossils, conventional geology must be wrong, and these and most other fossils are only a few thousand rather than many millions of years old. These claims largely spring from work on T.rex bones by paleontologist Mary Schweitzers. Interestingly, Schweitzer describes herself as an evangelical Christian, but does not see her work as supporting young earthism or refuting evolution. In fact, she has reportedly been dismayed by strict creationists not accurately reporting her work and conclusions. According to Barry Yeoman who interviewed her for an article in Discover, " Unlike many creationists, she finds the notion of a world evolving over billions of years theologically exhilarating." He quoted Schweitzer as saying "That makes God a lot bigger than thinking of Him as a magician that pulled everything out in one fell swoop." (Yeoman, 2006).
In July 2008 dinosaur researcher Tom Kaye et al published a paper providing strong evidence that at least some of the supposed soft tissues and vascular structures were actually "biofilms" produced by bacteria, or in the case of supposed blood cells, noncellular structures cammed framboids. When framboids are coated with biofilm, they can even resemble nucleated reb blood cells under a light microscope. Kaye's work appears to undermine creationists claims that "soft tissue" preservation is indisputable supports a young earth (Kaye et al, 2008). The controversy among paleontologist continues, but even if some cases of exceptional preservation of soft tissues can be demonstrated, the overall pattern of preservation (and species succession) seen in the fossil record still argues strongly against YECism. Indeed, the rarity of soft tissues, especially in Paleozoic Era, argues strongly against YECIs. According to YECs, most fossils were laid down during "Noah's Flood" and are no more than a few thousand years old. If so, then soft tissue should be common and abundant throughout the fossil record, and just as common in the Paleozoic as later sediments. But clearly it is not (Duff, 2013l) For more discussion on this topoc see Babinski (2005) and Hurd (2004, 2005)
Duff, Joel. 2013, Natural Historia web site, Young Earth Creationism and Ancient DNA. Natural Historia website article at: http://thenaturalhistorian.com/2013/12/05/ancient-dna-creationism-genome-sequencing
Hurd, Gary. 2004, Dino-blood and the Young Earth, Talk Origins website article at: http://www.talkorigins.org/faqs/dinosaur/blood.html Hurd, Gary. 2005, Dino Blood Redux. Web article at: http://www.talkorigins.org/faqs/dinosaur/flesh.html
Kaye TG, Gaugler G, Sawlowicz Z, 2008, Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms, PLoS ONE 3(7) Web version at: ">
Moore, Gary, 2005. Dinosaur Blood Revisited. Web article at: http://www.reasons.org/resources/apologetics/dinosaur_blood_revisited.shtml
Yeoman, Barry, 2006. Schweitzer's Dangerous Discovery, Discover, Vol. 27, April 2006. Web version at: http://discovermagazine.com/2006/apr/dinosaur-dna