While the surrounding rock was laid down about 11 million to 13 million years ago
, the zircons were as much as 65 million years old.
Recent reconstructions of carbon dioxide levels for the late Miocene time period (roughly 5 to 13 million years ago) suggest that CO2 concentrations for the period were only 200-350 parts per million.
The research team found that sea surface temperatures appeared to be highest in the early part of the late Miocene (around 12 to 13 million years ago), and gradually cooled throughout the late Miocene.
Although humans and chimps appear to have last shared a common genetic ancestor 13 million years ago
, McVean says that the figure does not necessarily mean that the human and chimp lineages separated then.
The whale (depicted above) lived between 12 million and 13 million years ago
, says Olivier Lambert, a vertebrate paleontologist at the National Museum of Natural History in Paris.
Soybean's set of chromosomes has copied itself at least twice, approximately 59 million years ago the first time and then again about 13 million years ago
, Jackson and his colleagues report in the Jan.
Then, 13 million years ago
, snakehead fossils disappeared from Europe.
According to the new study, reported in the June 13 Science, the Basin and Range reached some 3,000 meters above sea level 16 million years ago, then dropped to its present height by about 13 million years ago