Dinosaur amino acids:
Titanosaur eggshell contains a few of the most thermally stable amino acids, which are completely freed from their protein sequences and further degraded. These results are likely the most robust evidence of dinosaur protein-derived breakdown products.
Preprint: Saitta et al. 2020. bioRxiv
Pigments like melanin, carotenoids, and porphyrins can preserve deep in the fossil record and allow for the reconstruction of color patterns in organisms, such as dinosaurs.
Study: Roy et al. 2019. Biological Reviews
Video summary: HKU Faculty of Science