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Human ancestors survived the asteroid impact that killed the dinosaurs |  daily menu

Human ancestors survived the asteroid impact that killed the dinosaurs | daily menu

An in-depth analysis of the fossil record revealed the Cretaceous origin of placental mammals, the group that includes humans, dogs and bats, and showed that they coexisted with dinosaurs for a short time before they evolved. They are extinct, according to researchers published in the journal Current Biology.

The catastrophic devastation wrought on Earth by an asteroid impact killed all non-avian dinosaurs in an event called the Cretaceous-Paleogene (K-Pg) mass extinction.

Researchers have long debated whether placental mammals existed alongside dinosaurs before the mass extinction, or whether they only evolved after the dinosaurs’ demise.

fossils Placental mammals are only found in rocks less than 66m Years ago, when the asteroid hit the Earth, indicating that the group evolved after the mass extinction. However, molecular data have long suggested an advanced age for placental mammals.

The study, conducted by a team of paleobiologists from University of Bristol (UK) And the University of Fribourg, Switzerland, used a statistical analysis of the fossil record to determine that placental mammals arose before the mass extinction, which means they coexisted with dinosaurs for a short period of time.

However, modern lineages of placental mammals did not begin to evolve until after the asteroid impact, suggesting that They were able to diversify better after the dinosaurs disappeared.

The researchers collected extensive fossil data from groups of placental mammals dating back to the mass extinction 66 million years ago.

“We collected thousands of fossil placental mammals and were able to see the patterns of extinction of different groups,” explains Emily Carlyle, from the Bristol School of Geosciences and lead author of the study. Based on this, we were able to estimate the developmental time of placental mammals.”

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“The model used calculates ages of origin based on when the lineages first appear in the fossil record and on the pattern of species diversification over time,” explains co-author Daniel Silvestro, of the University of Freiburg. dynasty time. You can also estimate extinction ages based on when the group’s extinction last occurred.”

Co-author Professor Phil Donoghue, also from Bristol, notes, “By examining both the origins and the extinctions, we can clearly see the impact of events such as the K-Pg mass extinction or the Paleocene-Eocene Thermal Maximum (PETM).” “.

Show that Primates, the group that includes the human lineage, Just as Lagomorpha (rabbits and hares) and Carnivora (dogs and cats) evolved before the K-Pg mass extinction, that means their ancestors interbred with dinosaurs. After surviving the asteroid impact, placental mammals diversified rapidly, possibly due to the loss of competition from dinosaurs.