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What soft tissues were preserved in the B-rex Tyrannosaurus rex fossil?
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tyrannosaur
The fossilized remains of Sue, the most complete Tyrannosaurus rex skeleton in the world, on display at the Field Museum of Natural History, Chicago.
The "B-rex" Tyrannosaurus rex specimen, discovered in the Hell Creek Formation in 2000, is notable for the preservation of soft tissues within its fossil remains.12
These soft tissues include transparent, flexible, and hollow blood vessels. Within these vessels, scientists identified small, round microstructures that are highly reminiscent of the structure of red blood cells. Additionally, the specimen preserved medullary bone, a type of tissue that indicates the individual was female. The preservation of these delicate structures is considered one of the most remarkable features in the entire known fossil record.12