Scientists have long speculated that the extinction of the dinosaurs around 66 million years ago was due to starvation caused by a nuclear winter that followed a massive asteroid impact. However, new research suggests that the prehistoric animals' demise may have been quicker and more "hot."
A recent study published in the journal JGR Biogeosciences proposes that extreme heat and wildfires may have played a major role in the extinction/burning to death of terrestrial life at the time, including dinosaurs.
Scientists generally agree that when the 6-mile-wide Chicxulub meteorite struck Mexico's Yucatan Peninsula at the end of the Cretaceous Period, it vaporized large amounts of rock that condensed into tiny droplets.
These droplets, known as spherules, scattered around the planet before falling back into Earth's atmosphere at speeds of several miles per second. As the spherules slowed their free fall, their kinetic energy was converted into heat, creating an increase in thermal radiation.
Research claims that this heat wave was powerful enough to kill animals with thin skin, but not so intense as to set vegetation on fire and burn animals with thick skin such as dinosaurs.
But, in 2023, at the Tanis fossil site in North Dakota, researchers identified a layer of deposits above the spherules.
Researchers believe this fine dust cloud may have functioned as a kind of prehistoric insulating blanket, blocking thermal radiation at the Earth's surface and sparking fires around the world.
"With the dust cloud blocking the thermal radiation, it was like the surface was burning everything above it. That's what killed the dinosaurs and all the other animals," said author Brandon Johnson, a planetary scientist at Purdue University, in a statement.
Johnson and his team estimate that this heat blanket may have made the heat wave 3.5 times more powerful than previous calculations had estimated and intense enough to cause forest fires.
"It was a situation where everything could have been destroyed within the first hour or two," Johnson added.
The radiation may have ignited grass, lichens, and pine needles, which served as fuel for larger fires.
Terrestrial animals were exposed to a thermal dose 17 times higher than what is considered lethal for humans.
"It probably looked like hell," Johnson said. "The clouds had blocked out the sunlight, so to any animal, the surface would probably have looked dark."
Researchers believe that animals that lived in water or took shelter underground could have survived the heat pulse; but this troublesome dust that turned the Earth into a baking oven likely blocked out sunlight for several years, causing the long, hungry winter that has long been considered the final death knell for the dinosaurs.
Researchers claim that knowing whether animals were burned alive quickly or starved to death slowly is essential to understanding the impact that a major event like Chicxulub had on extinction, evolution and ecosystem recovery.
In 2022, another discovery shed light on why some species of mammals, crocodiles, turtles, and birds survived the Cretaceous period.
A team of scientists discovered that the planet's seasonal climate may have inadvertently protected some of those prehistoric animals.
Earlier, scientists confirmed that the skull of a very large dinosaur with a sword-like horn protruding from its head was found in Niger. The dinosaur, named Spinosaurus mirabilis, was 16-20 meters long and was about the same size as the mighty Tyrannosaurus Rex.
Recently, scientists discovered a strange “turducken” fossil that suggests something akin to a deadly nesting doll: a flying dinosaur was eaten by a 23-meter-long reptile, then devoured by a 12-meter-long sea monster. ©LAPSI.al
