Researchers have identified protein sequences within the dense enamel tissues of ancient nasal cavities and materials collected from the Burg and Lopelot sites in the Turkana Basin, Kenya.
The Turkana Basin within the East African lift system preserves fossil communities dating back more than 66 million years. Green et al. Powder samples were collected for paleontological skin analysis from the early Pleistocene back to the Oligocene (29 million years ago) from large herbivores. Image credit: Green et al., doi: 10.1038/s41586-025-09040-9.
“Teeth are the rocks in our mouths,” stated Dr. Daniel Green, a researcher at Harvard and Columbia University.
“They represent the most complex structures created by animals; hence, it’s possible to find teeth that are 100 million years old, offering geochemical records of animal life.”
“This includes insights into their diets, hydration, and habitats.”
“Previously, we believed that mature enamel, being the hardest part of teeth, should contain very little protein.”
Yet, by employing a novel proteomic technique known as liquid chromatography tandem mass spectrometry (LC-MS/MS), the researchers uncovered remarkable protein diversity in various biological tissues.
“The method comprises multiple stages where peptides are sorted according to size or chemistry, enabling detailed sequential analysis at unprecedented resolution,” explains Dr. Kevin Uno from Harvard and Columbia University.
“Recent findings indicate that there are dozens, potentially hundreds, of different proteins present in tooth enamel,” remarked Dr. Green.
Recognizing that many proteins exist in modern teeth, researchers pivoted towards studying fossils of nasal mesentery and related materials.
As herbivores, these creatures exhibited large teeth to crush their plant-based diets.
“These mammals could have enamels measuring 2-3 millimeters in thickness, providing ample material for investigation,” Dr. Green noted.
“Our discovery — peptide fragments and amino acid chains representing proteins spanning around 18 million years — stands to transform the field.”
“No one has previously identified peptide fragments of such antiquity.”
The oldest published findings to date date back around 3.5 million years.
“The newly identified peptides encompass a diverse array of proteins, representing what is known as the proteome,” Dr. Green remarked.
“One reason we are thrilled about these ancient teeth is that we lack a complete proteome for all proteins that could potentially be extracted from the bodies of these extinct elephants and rhinos, yet we can identify distinct groups.”
“Such collections could yield more information from these groups than from a single protein alone.”
“This research opens a new chapter for paleontology, enabling scientists to reconstruct the molecular and physiological traits of extinct species, moving beyond just bones and morphology,” stated Dr. Emmanuel Nudiemma, a researcher at the National Museum of Kenya.
“These peptide fragments can be utilized to delve into the relationships among ancient animals, much like contemporary methods that map human DNA relations.”
“Though a few animals analyzed in studies are completely extinct without living descendants, in theory, proteins could be extracted from their teeth and added to a phylogenetic tree,” Dr. Green elaborated.
“This information may clarify long-standing debates among paleontologists concerning the relationships among various mammalian lineages, utilizing molecular evidence.”
Survey results Today, I will be featured in the journal Nature.
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Dr. Green et al. Diverse enamel proteomes from rifts of East Africa over 108 million years. Nature Published online on July 9, 2025. doi:10.1038/s41586-025-09040-9
Source: www.sci.news
