Evidence for Endogenous Collagen in Edmontosaurus Fossil Bone.

Area of Science:

• Paleontology
• Biochemistry
• Geology

Background:

• Fossilization is widely believed to destroy all organic components, including proteins.
• Previous reports of proteins in fossils have faced scientific skepticism.
• Exceptional preservation may allow for the survival of biomolecules.

Purpose of the Study:

• To investigate the presence of proteins, specifically collagen, in an exceptionally preserved Edmontosaurus sacrum.
• To apply novel analytical techniques to address the controversy surrounding organic molecules in fossils.
• To provide robust evidence for or against collagen survival during fossilization.

Main Methods:

• Cross-polarized light microscopy (XPol) to detect birefringence indicative of collagen.
• Liquid chromatography-tandem mass spectrometry (LC-MS) to identify and quantify hydroxyproline, a collagen-specific amino acid.
• LC-MS/MS bottom-up proteomics to analyze collagen peptide sequences.

Main Results:

• XPol microscopy revealed birefringence consistent with collagen in the Edmontosaurus sacrum.
• Hydroxyproline was unambiguously identified and quantified in acid-digested samples, confirming collagen presence.
• Collagen peptide sequences matched those previously reported for other hadrosaurs and a Tyrannosaurus rex sample.

Conclusions:

• This study presents compelling evidence for the preservation of collagen in a Late Cretaceous Edmontosaurus fossil.
• The findings challenge the long-held assumption that fossilization completely obliterates organic matter.
• Advanced analytical techniques can successfully detect and characterize ancient biomolecules in exceptionally preserved specimens.