Describe ancient birds nest over the Arctic Circle
Gabriel Ulgoo
Newly found bone fragments from Alaska suggest that birds have born and nesting Arctic for at least 73 million years.
“Where is the kind of insanity, because it is not easy to live in Arctic and has newborn children there,” as the author of the study Lauren Wilson at Princeton University.
Today, about 250 bird species matches the development of land poles. Others move long distances and spend only summer there, with 24 hours of light every day. Some also remain in winter, suffering from heavy temperatures and infinite darkness in weeks in the end. But it was very small about how and the first birds went to the highest latitudes of the earth.
Wilson and his friends seek for traces of ancient birds with a series of stones known as the Princce Creek formation in northern Alaska, which was formed in a flooding of the beach that were about 73 million years ago. At that time, what is North Alaska about 1000 to 1600 kilometers approaching the North Pole than today.
The team captures chunks of ancient land from some thin layers of stone to form. This is during winter, if the temperature is -30 ° C (-22 ° F) and the house is a tent. “It’s definitely the worst job in the field I’ve done,” Wilson said.
Back to the laboratory, they “spent a lot of time staring” through a microscope “in the grains of sediment less than two millimeters”, Wilson prayed for small pieces of fossil bones.
They did not discover more than 50 ancient fossil fragments of birds from chicks or even embryonic birds. The fossilized bones of such young birds have a sponge-like sponge because they represent a stage when bones grow easily.
While birds may have started to nest in Arctic despite 73 million years ago, fossils are the oldest traces of this behavior found so far. They restore its record to birds in 30 million years.
However, fossils are very modified. They also do not show if the birds live in the year or during a warm summer.
“The arctic we know, especially the food webs do not exist in the cold and darkness, can’t have many birds calling the long callers Steve Brusatte At the University of Edinburgh, UK, not included in the study. “These fossils show that birds are important parts of these high-latitude communities for many millions of years ago.”
Wilson’s team will recognize three main birds groups between fossil fragments: lost birds of the same loons, and some species can belong to the same group as all modern birds.
Samples, however, no bones from a group of many archaic birds known to enannithines – or “opposite birds“- which reigns fossil records from that time around the world. Gerday mayr In the Sencenkenberg Research Institute in Germany, which is not also involved in studying, it is thought that it is a “important conditions to advance because the ancestral places in advance that the floors of birds without birds.
The ecosystem raises prince Creek forms a period of non-bird dinosaurs that distribute ecosstems in the arctic of Tyrannosaur and Horned Ceratopana. There is even evidence that some of the Nested Arctic dinosaurs also.
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