Micro-XRF Study Of The Troodontid Dinosaur Jianianhualong Tengi Reveals New Biological And Taphonomical Signals

Abstract

Jianianhualong tengi is a key taxon for understanding the evolution of pennaceous feathers as well as of troodontid theropods. It is known by only the holotype, which was recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. In this study, we carried out a large-area micro-X-Ray fluorescence (micro-XRF) analysis of the holotype of Jianianhualong tengi via a Brucker M6 Jetstream mobile XRF scanner. The elemental distribution measurements of the specimen show an enrichment of typical bone-associated elements, such as S, P and Ca, which allows to visualize the fossil structure. Additionally, the bones are enriched with several heavier elements, such as Sr, Th, Y and Ce relative to the surrounding rocks. The enrichment is most likely associated to secondary mineralization and the phosphates from the bones. Interestingly, the plumage shape correlates with an enrichment in elements, such as Cu, Ni and Ti, consistent with the findings of a previous study 1 on Archaeopteryx using synchrotron imaging. Elemental variations among the skeleton, the unguis and the sheath blade further indicate their possible compositional or ultrastructural differences, providing new biological and taphonomic information on the fossilized keratinous structures. An in-situ and nondestructive micro-XRF analysis is currently the most ideal way to map the chemistry of meter-sized fossils and has so far been mainly restricted to small samples. Micro-spatial chemical analysis of larger samples usually required a synchrotron facility. Our study demonstrated that a laboratory-based large-area micro-XRF scanner can provide a practical tool for the study of large specimens, thus allowing to collect full chemical data in order to obtain a better understanding of evolutionary and taphonomic processes.

Metallomics in Multidisciplinary Research and the Analytical Advances

“…In addition to their role in the above-mentioned branches of metallomics, metal(loid)s play an interesting role in the study of evolution and the origin of life, which involves the examination of geological samples such as fossils. 31 In this case, geometallomics, which combines metallomics with geological science, can be utilized. One example is a study on the elemental signatures in teeth from the extinct Australopithecus africanus, which found that dietary stress contributed to the disappearance of this genus.…”

Resolution enhancement in micro-XRF using image restoration techniques

“…In recent years, an increased number of benchtop micro X-ray fluorescence analysis (micro-XRF) and macro X-ray fluorescence analysis (macro-XRF) instruments have been developed, 1–5 and they have rapidly contributed to research in electronics manufacturing, 6 forensic sciences, 7,8 materials sciences, 9 botany, 10 geology, 11–17 and art history. 1,18–23 The main difference between micro-XRF and macro-XRF is the resolution at which the investigation is performed (typical 100 μm), 24 and we only refer to micro-XRF in this paper.…”

Non-Destructive Micro X-Ray Fluorescence Quantitative Analysis Of Geological Materials

“…Micro X-ray fluorescence (µXRF) is a promising alternative approach to overcome these drawbacks because it involves minimal sample preparation and therefore causes very limited or no damage to the sample. 14,15 It uses characteristic secondary (or fluorescent) X-rays from a material that has been bombarded by high-energy X-rays for elemental analysis. 16,17 Unlike conventional XRF which is typically used for bulk analysis of large material fractions, 18 µXRF uses X-ray optics to restrict the excitation beam size or to focus it to a small spot on the sample surface for chemical analysis on a small or minute scale (i.e., microanalysis).…”

“…22 Practically, scanning μXRF can work as a stateof-the-art, time-efficient, and non-destructive method for majorand trace-element analysis for both small and large samples (e.g., from micrometer to meter). 14,15,17,22 Furthermore, measurements can be carried out in a normal-or low-pressure environment inside the chamber, or a helium atmospheric environment. Various samples measured with scanning μXRF, such as rocks, sediments, and even soft biological tissues (e.g., leaves), do not need some additional embedding, polishing, and sputter coating pretreatments, 23,24 which are generally necessary for electron micro-spectroscopic and SIMS/NanoSIMS analyses.…”

“…15 Furthermore, X-rays interact more weakly with matter than electrons, while they have relatively higher penetration depth in the sample (up to 1 mm for X-rays compared to a few microns for electrons). 25 These advantages make μXRF increasingly popular in the chemical characterization of geological, 22,26 paleontological, 14,27,28 planetary, 15 archaeological, 29,30 cultural heritage, 31 and biological samples. 32 Besides obtaining chemical information at a high spatial resolution within a sample, 17,21,22,27 scanning μXRF can produce multi-element maps and single-element heat maps that can be used for quantifying modal abundance, sizes, shapes, and degrees of segmented components.…”