The PETM, which occurred 55.8 million years ago, is believed to have raised global average temperatures by five to nine degrees centigrade as five to ten billion tonnes of carbon dioxide was released into the atmosphere and oceans over a period of 10,000 years.
Prehistoric fish thrived during a severe global warming event 56 million years ago with ease, new paleontological finds in Egypt suggest.
The discovery of fossils of fish closely related to modern species at the Ras Gharib A site, dating from the Paleocene-Eocene Thermal Maximum (PETM), was important as there is little evidence in the fossil record from that time of how fish weathered the rapid climate change of the time.
The findings have been published in the scientific journal Geology.
The dozen species found at the site in the Eastern Desert, 200 miles southeast of Cairo, include percomorph acanthomorphs, a group that includes walleye, bass and bluegills, a moonfish of the Mene genus, deep-sea hatchet fish and the bony tongue predatory species which also has living relatives.
The PETM, which occurred 55.8 million years ago, is believed to have raised global average temperatures by five to nine degrees centigrade as five to ten billion tonnes of carbon dioxide was released into the atmosphere and oceans over a period of 10,000 years. There are not believed to have been any major permanent ice sheets at the time, even at the poles.
The team believes that the species found may in fact have thrived during the hot period enough to evolve into several new forms.
Egyptian paleontologist Sanaa El-Sayed, the study’s lead author, said the period of severe climate change appeared to have had no adverse effect on sea fish populations — noting that land animals also saw a great increase in abundance and diversity at the time.
While the PETM has been compared to the present era in terms of the rate of climate change, the current rate of carbon emissions is roughly ten times faster than it was then — although governments aim to cut that drastically within the next few decades.
Sourse: sputniknews.com
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