Genome-centric resolution of novel microbial lineages in a Centrosaurus fossil bone from the Late Cretaceous of North America

Exceptional preservation of endogenous organics such as collagens and osteocytes has been frequently reported in Mesozoic dinosaur fossils. The persistence of soft tissue in Mesozoic fossil bones has been challenged because of the susceptibility of proteins to degradation and because bone porosity allows microorganisms to colonize the inner microenvironments through geological time. Although protein lability has been studied extensively, the genomic diversity of microbiomes in dinosaur fossil bones and their potential roles in bone diagenesis remain underexplored. Genome-resolved metagenomics and metaproteomics were performed, therefore, on the microbiomes recovered from a Late Cretaceous Centrosaurus bone and its encompassing mudstone that were aseptically excavated in Dinosaur Provincial Park, Alberta, Canada, in order to provide insight into the genomic potential for bone alteration.