Soft tissue recovered from purportedly 68 million years old fossils of Tyrannosaurus rex Brachylophosauraus canadensis have been analyzed, and preservation mechanisms have been suggested by workers. A "preservation motif" based upon structure-function relationships at the molecular level is thought to explain the selective survival of soft tissue and particular peptide sequences. Preservation motifs include molecularly sheltered environments such as collagen fibril domains that offer tight molecular packing thereby conferring resistance to degradation. Sequences enriched with hydrophobic amino acid residues and depleted in acidic residues suggest another preservation pattern. More recent work by the same group adds that Fenton type reactions, arising from trace iron discovered with the bone tissue, is responsible for "fixing" the collagen for deep time survival. The present paper reviews these preservation motifs and supportive data in light of fast-degrading amino acids such as asparagine and glutamine, and oxidatively sensitive markers tyrosine, methionine, and histidine that survived the long burial age.