Scientists unlock new secrets from a male woolly mammoth tusk

Sign up for CNN’s Wonder Theory science newsletter. A team of researchers turned to elephant and mammoth tusks to see if their layers might also preserve the presence of steroid hormones like cortisol, said lead study author Michael Cherney, a research affiliate at the University of Michigan Museum of Paleontology and a research fellow at the University of Michigan Medical School. “I think the biggest surprise, however, was just how clear the pattern in testosterone was.” Tusks as time capsules The researchers studied three tusks during their analysis, including two adult mammoth tusks and one from an African bull elephant that was between 30 to 40 years old when it was killed by a hunter in Botswana in 1963. University of Michigan A tusk from a female mammoth that lived between 5,597 and 5,885 years ago on Wrangel Island was also used in the study. University of Michigan “Tusks hold particular promise for reconstructing aspects of mammoth life history because they preserve a record of growth in layers of dentin that form throughout an individual’s life,” said study coauthor Daniel Fisher, a curator at the University of Michigan Museum of Paleontology and professor in the Department of Earth and Environmental Sciences, in a statement.