Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

摘要: Soft tissues and cell-like microstructures derived from skeletal elements of a well-preserved Tyrannosaurus rex (MOR 1125) were represented by four components in fragments demineralized cortical and/or medullary bone: flexible fibrous bone matrix; transparent, hollow pliable blood vessels; intravascular material, including some cases, structures morphologically reminiscent vertebrate red cells; osteocytes with intracellular contents filipodia. The present study attempts to trace the occurrence these specimens spanning multiple geological time periods varied depositional environments. At least three persist dating Campanian. Fibrous matrix is more altered over morphology less likely than vessels osteocytes. Vessels vary greatly preservation, even within same specimen, regions retaining pliability other almost crystalline. Osteocytes also vary, long filipodia transparency, while others short stubby deeply pigmented nuclei, or are throughout no nucleus visible. Alternative hypotheses considered explain origin/source observed materials. Finally, twopart mechanism, involving first cross-linking molecular subsequent mineralization, proposed surprising presence still-soft fossil bone. These results suggest that models fossilization processes may be incomplete soft tissue commonly preserved, older specimens, previously thought. Additionally, many defined nuclei represent an important source for informative data.