Soft Tissue Retrieved from Dinosaur Fossil

Scientists investigating the inner structure of a Tyrannosaurus rex fossil discovered what appeared to be preserved soft tissues, perhaps including intact blood cells, as reported in the March 25, 2005 issue of Science. If confirmed, the unexpected finding could revolutionize our understanding of ancient life forms.

Biological tissues are generally not preserved in the geological record. If conditions are just right, minerals may gradually replace the original specimen over time, resulting in the rare fossil. This mineralization process often erases the finer detail of the original biological structures. The new finding may indicate a previously unknown process by which original biological tissues can be preserved for many millions of years. Researchers will continue studying the specimen retrieved from the Tyrannosaurus rex fossil to determine if it really is the original soft tissue material. Alternatively, researchers may have stumbled upon a “soft” mineralization process by which the fossil retains some of the flexibility and detail of the original specimen, though this seems unlikely.

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Richard Leis

Richard Leis is a writer and poet. His first published poem, "Roadside Freak Show," arrives on August 21, 2017 in Impossible Archetype.  His essays about fairy tales and technology have been published on Tiny Donkey. Richard is also the Downlink Lead for the High Resolution Imaging Science Experiment (HiRISE) team at the University of Arizona. He monitors images of the Martian surface taken by the HiRISE camera located on board the Mars Reconnaissance Orbiter in orbit around Mars and helps ensure they process successfully and are validated for quick release to the science community and public. Once upon a time, Richard wrote and edited the science and technology news and commentary website Frontier Channel, hosted the RADIO Frontier Channel podcast, and organized transhumanist clubs. Follow Richard on his website (, on Goodreads (richardleis), Twitter (@richardleisjr), and Facebook (richardleisjr).