The Elastic Tissue of T. rex

Fig. 2

Mary Schweitzer is one of the few paleontologists looking for the preservation of anything other than the highly mineralized fossil bones that form the foundations of vertebrate paleontology. If anything her quest is a challenging one. Sixty Five million years is a long time and not much is left of the soft tissue, which often decays in the first few weeks after death. But in todays issue of Science she and several collegues have isolated microstructures which have cell-like morphology within vessels that may represent blood vessels and blood cells. Although the article includes the conservative statement "reveals transparent flexible vessels in what remains of the cortical bone matrix, represented by a brown amorphous substance."

Schweitzer, Mary H., Wittmeyer, Jennifer L., Horner, John R., Toporski, Jan K.
Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex
Science 2005 307: 1952-1955