Our Fine Feathered Ancestors & Why We Think Dinosaurs had Beautiful Feathers
Why did dinosaurs have feathers millions of years before the first reptiles took to the air?
Paleontologists have been puzzling over that question for years. But now an answer may finally be at hand, thanks to a fascinating new study by researchers at the University of Bonn in Germany.
“Until now, the evolution of feathers was mainly considered to be an adaptation related to flight or to warm-bloodedness,” the study’s first author Marie-Claire Koschowitz, a graduate student at the University’s Steinmann Institute for Geology, Mineralogy and Paleontology, said in a written statement. “I was never really convinced by any of these theories.” Instead, the study suggests plumage evolved in dinosaurs because its bright coloration facilitated communication and mate selection.
Koschowitz and her team came up with the idea after analyzing genetic similarities between dinosaurs and modern-day reptiles and birds. The analysis led them to hypothesize that dinosaurs had “tetrachromatic” vision — in other words, they had four photo-receptors to detect ultraviolet light as well as blue, green, and red just like birds do today.
“If you look at a (tree of life genetic diagram) for a group of animals for which the relationships are well known and you find a feature that is shared by all of them, it’s pretty safe to assume that this feature was present at the base of the tree and kept throughout the evolution of the last common ancestor into the different species,” Koschowitz told The Huffington Post. “So I looked at the morphology and general color vision in reptilia and birds and lo and behold, it turned out that tetrachromacy is present in every single branch of today's reptiles.”
This means dinosaurs likely used vivid visual signals to communicate with each other, Koschowitz said. Developing large, sheet-like feathers would have resulted in a huge variety of colors and patterns they could use to recognize one another — and mate.
All dinosaurs were covered with feathers or had the potential to grow feathers, a study suggests.
The discovery of 150-million-year-old fossils in Siberia indicates that feathers were much more widespread among dinosaurs than previously thought. The find "has completely changed our vision of dinosaurs", the lead researcher told BBC News. The details have been published in the journal Science.
“It is a big discovery. It has completely changed our vision of dinosaurs”, said Dr. Pascal Godefroit at the Royal Belgian Institute of Natural Sciences. The creature, called Kulindadromeus zabaikalicus, was about one meter long, with a short snout, long hind legs, short arms, and five strong fingers. Its teeth show clear adaptations for chewing plants. Until now, fossilized evidence of feathery dinosaurs has come from China and from a meat-eating group called theropods.
The latest discovery, in Russia, is from a completely separate group of plant-eating dinosaurs called ornithischians - which accounts for half of all dinosaurs. The find takes the origin of feathers millions of years further back in time than had previously been thought, said Dr. Pascal Godefroit of the Royal Belgian Institute of Natural Sciences in Brussels, Belgium, who led the research.
"It was a big surprise," he said. “Instead of thinking of dinosaurs as dry, scary scaly creatures a lot of them actually had a fluffy, downy covering like feathers on a chick” – Dr. Maria McNamara, Cork University in Ireland.
"The fact that feathers have now been discovered in two distinct groups, theropods in China and ornithischians in Russia means that the common ancestor of these species which might have existed 220 million years ago also likely had feathers."
An Alternative view...
So do all the pictures of dinosaurs in children's books need to be redrawn to make creatures like Triceratops, Stegosaurus, Tyrannosaurus rex and the vicious Velociraptor, fluffier and cuter? Perhaps a little bit, according to Professor Mike Benton, of Bristol University, who was also involved in the work. "Our research doesn't mean that all dinosaurs had feathers, especially as adults," he told BBC News.
"Some will have had feathers as young animals and kept them throughout their lives. Others may have lost feathers as they grew up, and became large enough not to need them, or replaced feathers with scales or relied on bony plates in the skin for protection."
The key point is that dinosaurs were all initially feathered and warm blooded, confirmation of an idea that has prevailed for years, he said. "Feathers were used first for insulation and signaling; they only later became adapted for flight."
But Dr. Paul Barrett of the Natural History Museum in London, has doubts. "Most feathers have a branching structure," he told BBC News. "Instead these look like little streamers coming from a central plate. No bird has that structure in any part of its plumage and none of the developmental models that biologists use to understand the evolution of feathers includes a stage that has anything like that kind of anatomy."
As of note: There is one single gene that controls whether or not an animal grows scales, hair or feathers. This single gene expresses itself across the entire spectrum of lizards, birds and mammals pointing to a common ancestor millions of years back. Of interest to me is the fact that the gene is mutated (has an error) in all of humanity (homo-sapiens) and that’s why we don’t grow as hairy as our other primate cousins.
Article Credits: http://www.huffingtonpost.com/2014/11/07/evolution-feathers-dinosaurs_n_6100020.html?ir=Weird+News
Image Credits: Emily Willoughby, Deviant art Artist
Update to this article:
First Dinosaur Tail Found Preserved in Amber
To scientists' delight, the incredible appendage from 99 million years ago is covered in feathers.
The tail of a 99-million-year-old dinosaur, including bones, soft tissue, and even feathers, has been found preserved in amber, according to a report published today in the journal Current Biology.
While individual dinosaur-era feathers have been found in amber, and evidence for feathered dinosaurs is captured in fossil impressions, this is the first time that scientists are able to clearly associate well-preserved feathers with a dinosaur, and in turn gain a better understanding of the evolution and structure of dinosaur feathers.
While most paleontologists dig up prehistoric bones from the ground, Lida Xing hunts for fossils in the amber markets of Myanmar. In 2015, he made a remarkable find: Trapped in what looked like golden glass was the feathered tail of a dinosaur.
Along with the primitive plumage, the 99-million-year-old amber also preserved soft tissue and eight complete vertebrae. The tail bones indicated that the specimen belonged to a dinosaur that was not a prehistoric bird and also provided researchers with insight into the evolution of feathers.
“This is the first time that skeletal material from a dinosaur has been found in amber,” Dr. Xing, who is a paleontologist at China University of Geosciences in Beijing, said in an email. He and his colleagues published their findings Thursday in the journal Current Biology.
After performing a CT scan and microscopic analysis, Dr. Xing and his colleagues realized that the feathers did not belong to a bird because the specimen’s tail vertebrae were not fused into a rod, as they are in modern birds. The feathers most likely belonged to a baby nonavian theropod, meaning it looked more similar to a velociraptor or Tyrannosaurus rex than to a modern bird. That said, it was probably only about the size of a sparrow.