Independent Evidence for the Preservation of Endogenous Bone Biochemistry in a Specimen of Tyrannosaurus rex
by Jennifer Anné 1,*,Aurore Canoville 2,Nicholas P. Edwards 3ORCID,Mary H. Schweitzer 4,5,6 andLindsay E. Zanno 4,5
1 The Children’s Museum of Indianapolis, Indianapolis, IN 46208, USA
2 Stiftung Schloss Friedenstein Gotha, 99867 Gotha, Germany
3 Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
4 Department of Biological Sciences, Campus Box 7617, North Carolina State University, Raleigh, NC 27695, USA
5 Paleontology, North Carolina Museum of Natural Sciences, 11 W. Jones St., Raleigh, NC 27601, USA
6 Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
* Author to whom correspondence should be addressed.
Biology 2023, 12(2), 264; https://doi.org/10.3390/biology12020264
Received: 29 December 2022 / Revised: 3 February 2023 / Accepted: 4 February 2023 / Published: 7 February 2023
(This article belongs to the Special Issue Paleontology in the 21st Century)
The Tyrannosaurus rex fossil known as Stan is displayed in a gallery at Christie’s auction house in New York City on September 17, 2020.
Photograph by Spencer Platt, Getty Images
Simple Summary
Our understanding of what can preserve in the fossil record, and for how long, is constantly evolving with the use of new scientific techniques and exceptional fossil discoveries. In this study, we examine the state of preservation of a Tyrannosaurus rex that died about 66 million years ago. This specimen has previously been studied using a number of advanced methods, all of which have indicated preservation of original soft tissues and bone biomolecules. Here, we use synchrotron—a type of particle accelerator—analyses to generate data identifying and quantifying elements that constitute this fossil bone. We show that trace elements incorporated by the living animal during bone deposition and remodeling, such as zinc, are preserved in the fossil bone in a pattern similar to what is seen in modern bird bones. This pattern is not observed in a microscopically well preserved, but molecularly more degraded dinosaur, a herbivorous Tenontosaurus. These data further support the preservation of original biological material in this T. rex, suggesting new possibilities for deciphering extinct species life histories. This study also highlights that preservation of original biochemistry in fossils is specimen-specific and cannot be determined by pristine appearance alone.
Abstract
Biomolecules preserved in deep time have potential to shed light on major evolutionary questions, driving the search for new and more rigorous methods to detect them. Despite the increasing body of evidence from a wide variety of new, high resolution/high sensitivity analytical techniques, this research is commonly met with skepticism, as the long standing dogma persists that such preservation in very deep time (>1 Ma) is unlikely. The Late Cretaceous dinosaur Tyrannosaurus rex (MOR 1125) has been shown, through multiple biochemical studies, to preserve original bone chemistry. Here, we provide additional, independent support that deep time bimolecular preservation is possible. We use synchrotron X-ray fluorescence imaging (XRF) and X-ray absorption spectroscopy (XAS) to investigate a section from the femur of this dinosaur, and demonstrate preservation of elements (S, Ca, and Zn) associated with bone remodeling and redeposition. We then compare these data to the bone of an extant dinosaur (bird), as well as a second non-avian dinosaur, Tenontosaurus tilletti (OMNH 34784) that did not preserve any sign of original biochemistry. Our data indicate that MOR 1125 bone cortices have similar bone elemental distributions to that of an extant bird, which supports preservation of original endogenous chemistry in this specimen.
Keywords: synchrotron; bone remodeling; elemental analysis; molecular paleontology; diagenetic alteration
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