Feathers May Have Helped Dinosaurs Survive Their First Apocalypse

The dinosaurs ruled the earth. They had to survive the end of the world.

The mass extinction event is thought to have been caused by huge volcanic eruptions. The extinction of 80 percent of life on the planet is thought to have been caused by this cataclysm. Most extinctions took place among marine life, but how exactly the extinction event affected life on land has been a long standing geologic puzzle. The question of whether the dinosaurs survived a global heat wave or a cold snap has been added to the puzzle. The idea that the dinosaurs were able to survive the cold of a volcanic winter has been thrown into doubt by the discovery of icy lakes.

When enough lava to fill the Grand Canyon 500 times over cascaded across the center of Pangaea, the dinosaurs had no way of knowing the weather. Climate chaos was caused by the release of carbon dioxide and sulfur from the volcanos at the same time. All the carbon dioxide made the sea too acidic and killed off ocean dwellers. Global temperatures could have been stressed by the greenhouse gas, according to geologists. The causes of death on land are not as clear as they are for the sea, and there may be other important climate processes at play.

Sulfur from volcanic eruptions can form tiny reflective droplets in the atmosphere that bounce sunlight back into space, cooling the planet and possibly leading to a short-lived "volcanic winter." Humans have experienced this effect firsthand in events such as the worldwide spell of cooler conditions that followed the 1991 eruption of Mount Pinatubo in the Philippines. Computer simulations show that a volcano-caused winter at the end of the Triassic could have caused temperatures to tank by up to 10 degrees Celsius.

Climate-sensitive processes that can leave clues in rocks are used to determine if warming or cooling influenced land. It is possible to look for the fossils of the ancestors of modern cold-in tolerant plants, which shift toward or away from the equator. We don't have a good idea of ancient plants. There is still debate about whether the remains of lush, fern-filled forests across most of Pangaea are evidence of a warm or cold climate. There are more fingerprints of cold temperatures.

Rocks and dirt on the shore can freeze if ice forms on the lake. Sand or pebbles that could have been used in a ride are dropped when the ice breaks. The work of ice can be seen when sand or gravel is found on the shoreline.

In a new study published on Friday in Science Advances, researchers spotted a pattern in ancient lake- bottom rocks from the Junggar Basin, an area in northwest China that used to be part of Pangaea.

Evidence of ice can be found in the same rock layers where dinosaur footprints can be found on the ancient lake's shore. People have been looking for polar dinosaurs for a while. The co-author of the study says that they have no evidence that the polar regions are cold. Dinosaur footprints were found near the lake deposits.

The dinosaurs that lived in the late Triassic and later Dinosaurs had feathers, and so did the birds with feathers. The latter are similar to a long hair. The evolution of dinosaur feathers has not been seen in a fossil record. It's in line with a theory that there was a single evolution of feathers in dinosaurs.

Dinosaurs taking advantage of an end-Triassic cold snap help other patterns in the fossil record. There is no evidence of feathers in the evolutionary family tree of the pseudosuchians. If volcanic carbon dioxide had caused a heat wave, paleontologists think that pseudosuchians would have been able to survive. After the end of the Triassic, the skeletons and footprints of these reptiles are all but gone from the record. It really doesn't work very well. Everything that wasn't insulated on land died.

According to Randy Irmis, a paleontologist at the University of Utah who was not involved with this study, there is still a lot more to be learned. Trying to clarify links between potential kill mechanisms and certain groups of organisms is one of the hardest problems to untangle.

Finding more dinosaurs around Pangaea's former poles and more clear signs of low temperatures outside of the Junggar Basin are crucial to figuring out what conditions killed the pseudosuchians. "What would be nice is to see this kind of evidence in other polar geographical regions, which I've worked with on other aspects of the end-Triassic extinction." It could be the weather or a seasonal location. It is more widespread, you need to know that. The implications go beyond just this event. Understanding the six mass extinctions that are associated with sudden climate change is critical for understanding where we are going in the future. The only way to do that is to look at the geologic record.