Dinosaur proteins: Preservation of endogenous biomolecules in the fossil record
EMSL Project ID
50015
Abstract
A major goal in paleontology is to extract as much information possible from the fossilized remains that contain the history of life on Earth. We use preserved biomolecules (e.g., DNA, proteins and lipids) as indicators of the chemical and physical processes that occurred during the life of an extinct animal and where it falls in an evolutionary and phylogenetic context. However, the degradation of biomolecules with high preservation potential (e.g., proteins, amino acids and lipids) and the mechanisms that enable them to persist in the sedimentary record for 10s of thousands, millions or even hundreds of millions of years are not well understood. In the first chapter of my PhD dissertation, I examined biomolecule preservation in the ‘shallow’ fossil record (up to ~150,000 years), using mass spectrometric analyses of amino acids (the building blocks of proteins) and analyses of lipids (e.g., fats and sterols) in mammoth fossils from different depositional settings (i.e., permafrost, natural asphalt, a sinkhole, a channel deposit), combined with maturation experiments (that range from 100° C to 250° C to approximate diagenetic changes) on modern elephant bone. This combination of techniques demonstrates the same degree of biomolecule preservation and levels of degradation: the permafrost sample retained the most organic information and has experienced the least degradation (e.g., all 20 whole amino acids were present) whereas the mammoth rib from the hot spring fed sinkhole retains the least biomolecular information (e.g. only 12 whole amino acids were present). The main amino acids that make up collagen (i.e., glycine and proline) are among the most thermally stable, and persist in all fossil samples and through out all of the maturation experiments, indicating the high preservation potential of the constituents of collagen. The next portion of my dissertation will take this series of methods that I developed with the mammoth fossils back in time to the dinosaur fossil record (up to ~210 million years). I will analyze amino acids and lipids, which will likely preserve on considerably long time scales. The addition of a peptide-scale analysis of this dataset will enable me to make better interpretations regarding the endogeneity of the biomolecules present in dinosaur bones. The use of the 21 FTICR, which has extremely high resolution, would allow me to add another dimension to my analysis, with the goal of determining if it is possible for endogenous proteins to preserve in dinosaur bones.
Project Details
Project type
Limited Scope
Start Date
2018-03-01
End Date
2018-05-01
Status
Closed
Released Data Link
Team
Principal Investigator