We don't really know what happened to the animals, but they all seem to have disappeared at the same time, about 13 million years ago
,'' Reynolds said.
There had to have been a river flowing over a land connection 13 million years ago.
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.
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 new rate suggests that humans and chimps last shared a common ancestor 13 million years ago.
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