Just a few tiny dinosaur fossils discovered in the United States are changing paleontologists' understanding of the global history of dinosaurs.. The study was published in the Zoological Journal of the Linnean Society, writes ScienceAlert.

U Focus. Technologies has its own Telegram channel. Subscribe so you don't miss the latest and most exciting news from the world of science!

Scientists have discovered the fossilized remains of a tiny dinosaur that was the size of a chicken but had a very long tail.. Radioisotope analysis showed that these fossils are 230 million years old.. Thus, the dinosaur discovered in the USA, called Ahvaytum bahndooiveche, is now the oldest dinosaur in the Northern Hemisphere of our planet.

Scientists say dinosaurs are considered gigantic creatures, but they were originally much smaller in size..

The tiny dinosaur is the oldest species to live in Laurasia, the ancient continent that formed after the supercontinent Pangea broke up and formed modern Eurasia and North America. At the same time, it was previously believed that dinosaurs did not live in this time period in the Northern Hemisphere, but were mainly distributed on the continent of Gondwana, the southern part of the supercontinent Pangea.

According to scientists, only 6-10 million years separate the fauna of Gondwana and the oldest known location of dinosaurs in the Northern Hemisphere. Fossils of Ahvaytum bahndooiveche discovered in Wyoming now provide evidence that the conventional wisdom that dinosaurs were confined to Gondwana for tens of millions of years before spreading into Laurasia needs to be revised.

The study's authors say understanding of the origins of dinosaurs has been skewed by the apparent lack of fossilized remains of dinosaurs in Laurasia between 237 and 227 million years ago.. This discovery indicates that dinosaurs spread almost simultaneously across land in both the Southern and Northern Hemispheres, although previously thought otherwise.

The above time period is known for significant climate changes on Earth, which caused the planet to become wetter and warmer. Therefore, previously unsuitable places for life have become suitable for a variety of life forms..

Climate barriers are thought to be the main reason for the lack of dinosaur fossils in the Northern Hemisphere between 237 and 227 million years ago, but scientists think it may have more to do with environmental conditions that make preserving fossils more difficult. And all the exceptions were the bones Ahvaytum bahndooiveche.

Scientists found only fragments of dinosaur paws and no complete specimens, although this is quite typical for fossils of this age. However, paleontologists have been able to reconstruct the appearance of the dinosaur, and they believe that this creature is a relative of sauropods. The most famous members of this clade are Brachiosaurus and Diplodocus, herbivorous dinosaurs that were gigantic in size and lived millions of years later than Ahvaytum bahndooiveche.

As Focus already wrote, Punk and Emo, 430 million years old, are challenging established views. Researchers have discovered two ancient fossils that suggest ancient mollusks were more complex and adaptive than previously thought..

Focus also wrote that freshwater species may disappear from the face of the Earth. Nearly one in four freshwater species is at high risk of extinction, researchers have found..