Mysterious event nearly wiped out sharks 19 million years ago
By Yasemin Saplakoglu, Live Science, June 3, 2021
"It's unknown whether the ancient sharks died off in a single
day, weeks, years or even thousands of years."
The paper is:
Elizabeth C. Sibert and Leah D. Rubin, 2021
An early Miocene extinction in pelagic sharks
Science 04 Jun 2021: Vol. 372, Issue 6546, pp. 1105-1107
DOI: 10.1126/science.aaz3549
Yours,
Paul H.