Testes moleculares apoiam a viabilidade de elementos terrestres raros como agentes preservadores de biomoléculas fósseis

terça-feira, março 16, 2021

Molecular tests support the viability of rare earth elements as proxies for fossil biomolecule preservation

Paul V. Ullmann, Kristyn K. Voegele, David E. Grandstaff, Richard D. Ash, Wenxia Zheng, Elena R. Schroeter, Mary H. Schweitzer & Kenneth J. Lacovara

Scientific Reports volume 10, Article number: 15566 (2020)


Reproduced, with permission from Geochimica et Cosmochimica Acta, from Ullmann et al.

Abstract

The rare earth element (REE) composition of a fossil bone reflects its chemical alteration during diagenesis. Consequently, fossils presenting low REE concentrations and/or REE profiles indicative of simple diffusion, signifying minimal alteration, have been proposed as ideal candidates for paleomolecular investigation. We directly tested this prediction by conducting multiple biomolecular assays on a well-preserved fibula of the dinosaur Edmontosaurus from the Cretaceous Hell Creek Formation previously found to exhibit low REE concentrations and steeply-declining REE profiles. Gel electrophoresis identified the presence of organic material in this specimen, and subsequent immunofluorescence and enzyme-linked immunosorbant assays identified preservation of epitopes of the structural protein collagen I. Our results thereby support the utility of REE profiles as proxies for soft tissue and biomolecular preservation in fossil bones. Based on considerations of trace element taphonomy, we also draw predictions as to the biomolecular recovery potential of additional REE profile types exhibited by fossil bones.