Ellie Johnstonab, Faith Vandenbergab, Ryan Andersonb, and Joel Brownb, aArizona Christian University, 1 W. Firestorm Way, Glendale, Arizona 85306; bCreation Research Society, 1 W. Firestorm Way #145 Glendale, Arizona 85306. ejohnston22@arizonachristian.edu KEYWORDS collagen decay, dinosaur, FTIR, bone collagen ABSTRACT Collagen is the most abundant protein in vertebrates. Due to its compact triple helical structure, collagen is exceptionally stable; however, it is still subject to spontaneous hydrolytic reactions which break peptide bonds and ultimately lead to its degradation. In 1997, Mary Schweitzer published some of the first evidence of extant biological tissue in dinosaur bones (Schweitzer 1997). Since then, numerous studies have reported a range of surviving structures in dinosaur bones including blood vessels, osteocytes, and endogenous proteins such as collagen (Boatman 2019). Based on the assigned ages of these fossils (>65 Ma), the presence of endogenous biomolecules such as collagen was surprising because of theoretical limits on the persistence of proteins through deep time. The presence of such proteins has led to speculation about the processes that regulate collagen decay, yet few studies have measured the decay rate of bone collagen. The presence and relative abundance of bone collagen can be tested by using Fourier-transformed infrared (FTIR) spectroscopy to measure spectral absorbance patterns of powderized bone samples (Scaggion 2024; Thomas 2023). Our lab has pioneered the use of FTIR to examine changes in the amount of bone collagen in artificially degraded samples. By subjecting modern bone fragments to heat, we accelerate the decay rate of bone collagen and can construct decay curves to calculate the rate of collagen degradation at paleontologically relevant temperatures. To better understand the taphonomic differences between animal taxa, we are measuring bone collagen decay in mammalian, avian, and reptilian bones. By using this artificial degradation protocol, we have calculated the half-life for bone collagen at 25℃ in a neutral aqueous environment to be 1086 yrs and 296 yrs for mammalian and avian bone, respectively. Although it is a stable protein, under these conditions bone collagen levels will drop below 1% in less than 10,000 years. Even at lower temperatures (i.e. 10℃), the life expectancy of collagen falls far short of the conventional ages assigned to the dinosaur bones in which it is found. While several factors impact collagen decay besides thermal properties, such as the presence of microorganisms which would accelerate decay and the presence of cross-linking which may prolong decay, our data establish a baseline with which to compare future experiments testing proposed models of preservation. If reasonable natural preservation methods cannot be identified which significantly extend the decay rate of collagen, then the assigned ages of these fossils should be re-examined. REFERENCES Schweitzer, M. H., C. Johnson, T.G. Zocco, J.R. Horner, and J.R. Starkey. 1997. Preservation of biomolecules in cancellous bone of Tyrannosaurus rex. Journal of Vertebrate Paleontology 17(2):349–59. https://doi.org/10 .1080/02724634.1997.10010979. Boatman, E.M., M.B. Goodwin, H.-Y.N. Holman, S.Fakra, W. Zheng, R.Gronsky, and M.H. Schweitzer. 2019. Mechanisms of soft tissue and protein preservation in Tyrannosaurus rex. Scientific Reports 9(1):15678. https://doi.org/10.1038/s41598-019-51680-1. Scaggion, C., M.Marinato, G. Dal Sasso, L.Nodari, T.Saupe, S.Aneli, L.Pagani, C.L. Scheib, M.Rigo, and G. Artioli. 2024. A fresh perspective on infrared spectroscopy as a prescreening method for molecular and dtable isotopes analyses on ancient human bones. Scientific Reports 14(1):1028. https://doi.org/10.1038/s41598-024-51518-5. Thomas, B., K. Anderson, I. De Silva, G. Verbeck, and S. Taylor. 2023. Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy sensitivity to the thermal decay of bone collagen. Applied Spectroscopy 77(1):53–61. https://doi.org/10.1177/00037028221135634. 14 2025 New Scholars Johnston, E., F. Vandenberg, R. Anderson, and J. Brown.. 2025. Establishing decay rates for bone collagen in different organisms using Fourier Transformed Infrared (FTIR) spectroscopy. In J.H. Whitmore (editor), Proceedings of the 2025 New Scholars International Conference on Creationism, p. 14. Cedarville, Ohio: Cedarville University International Conference on Creationism [oral presentation]. ESTABLISHING DECAY RATES FOR BONE COLLAGEN IN DIFFERENT ORGANISMS USING FOURIER TRANSFORMED INFRARED (FTIR) SPECTROSCOPY New Scholars 2025
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