The Eutyranus, which lived in the early Cretaceous, a relatively cool period, boasted feathers similar to those of a baby chick, which helped keep it warm
Paleontologists have known for more than a decade that some small dinosaurs had feathers similar to the ones birds today, thanks in large part to well-preserved fossils in northeastern China. Now three individuals of a dinosaur unknown to science and much larger that wore feathers were discovered in the same area.
The name of the new species, Yutyrannus huali, means "beautiful feathered tyrant" in a combination of Latin and Mandarin. The three individuals were collected from a layer in a quarry dating to the Cretaceous period in Liaoning Province. They are described by Chinese and Canadian scientists in this week's issue of Nature.
"The plumage of the Eutyranus was depleted," explains Prof. Zu Xing of the Institute of Reptile Paleontology and Planetthropology in Beijing, the lead researcher on the study. "They were more reminiscent of the feathers of a young chick than the dense cover of adult birds."
Researchers estimate that an adult Eutyranus reached nine meters in length and weighed about 1,400 kg, which made it significantly smaller than its famous relative, Tyrannosaurus rex, so that it still weighed 40 times more than the largest feathered dinosaur known to science so far. Beipiaosaurus. The size of the Eutyranus and the sparse structure of its feathers would not have allowed it to fly, but feathers have another important function as we know: insulation.
"The idea that the primitive feathers were used for insulation and not for flight has been around for a long time," says Dr. Corwin Sullivan, a Canadian paleontologist involved in the research. "However, large-bodied animals conserved heat quite easily, and actually had a greater problem of overheating. This makes the Yotyranus, which is big and shaggy, a surprise."
The explanation may have to do with climate, the researchers say, while the Cretaceous period was generally warm, the Euthyranos lived during the middle period of the early Cretaceous, when temperatures were slightly cold.
The tee. The giant rex, and its direct relatives on the other hand, lived in a time when conditions were warm, in the late Cretaceous. Isolated pieces of skin preserved from these animals showed that they were covered with scales rather than feathers, but the possibility that they were partially covered with feathers cannot be ruled out.
"Jutyrans dramatically increased the range of dinosaurs that we believe were feathered," said Prof. Zo. "Feathers may have been a much more common feature, at least among meat-eating dinosaurs, than most scientists would have guessed even a few years ago."
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I knew there were feathered dinosaurs but I wasn't sure the Tyrannosaurus rex had feathers
to the doubter,
I was not convinced of the correctness of the original argument but I learned a lot from you 🙂
Thanks
Amit.
You can totally disagree with me, but that still doesn't change the fact that you're wrong. You don't know the theory of evolution very well (although you seem to).
When I talk about "expensive" evolution, I mean evolution that has "many" intermediate stages. Such an evolution can only develop if there is a "survival bonus" at each intermediate stage. The development of feathers for "ornamental-mating" purposes only has no survival value in the intermediate stages, because when the ornamental feathers are not developed, the mating decoration is not seen.
Regarding the principle of respect, in my opinion (and in the opinion of many) it is a very dubious principle (even though in Israel it is given some importance because of the respect given to a golden adoption). It's a shame that this principle confuses the minds of good people who reach wrong conclusions.
Regarding the peacock's tail, according to an examination I conducted, the most likely is that the "very long" peacock's tail is the result of artificial selection (for beauty purposes) just as the Chihuahua dogs were bred for beauty purposes. According to the principle of respect, the Chihuahua dog reduced itself for the reasons of the "principle of respect" (to show that it survives despite being small in body), but this smallness is not convincing because we are well aware of the artificial selection that created the Chihuahua breed.
Originally, the length of the peacock's tail (male) was probably similar to the length of the peacock's tail, perhaps a little longer. The African (male) peacock has a tail that is as long as the tail of an (African or Asian) peacock, this is because no artificial selection was made on it for decoration purposes.
The peacock belongs to the pheasant family, all of which have somewhat long tails.
The rather long tail of peacocks helps them as predators of small ground animals, for example hunting snakes. (A somewhat long tail allows peacocks to hunt animals by improving the coordination of the body while they are perching on the prey. Improved coordination: tilting a large tail in one direction causes the body to move forward to the opposite side due to the law of conservation of momentum).
Some of the rooster pheasants (such as the domestic rooster and turkey) use the tail as a mating ornament. A turkey also spreads its tail in a fan shape like the male Asiatic peacock does. But - the tail of the roosters did not develop from scratch for the purpose of mating decoration, its use as a mating decoration was made *retrospectively* after the somewhat long tail already existed (a process I called "cheap evolution").
The (civilized) peacock, by the way, does not survive at all in the wild, in fact it is in a state of extinction. The long-tailed peacock is raised entirely (more or less) in peacock farms, it is sold from the farms (to private individuals or zoos), or sent to the wild in India (to tourist areas). Some of the peacocks that run away from the farms or their owners somehow manage to live a wild life, until they are hunted, or they escape to few niches in nature where they have no natural enemies today.
to the doubter,
I completely disagree with your claim that: "The claim that feathers evolved for the purpose of sexual decoration is completely improbable, since the evolutionary effort is not worth the result (there are many "cheaper" ways of decoration in terms of evolutionary effort, for example pigmentation of the skin or vocalization)"
Mainly because of the fact that the phrase "evolved for necessity" does not exist in evolutionary terms: there are changes and natural selection, when natural selection is extremely significant and the example of the peacock that literally shouts its presence to predators is an argument that is difficult to disagree with.
Are there cheaper ways of sexual reproduction? Maybe, but it's not an exact mathematical function, there are environmental conditions where it might be the cheapest way.
The most likely scenario in my opinion is that different species had different scenarios depending on the evolutionary pressures, there is not necessarily a single line for the development of the feathers. It could also be that evolution "invented" the feathers several times in different variations, and maybe we will never know that either...
Due*
safkan
In general, your words resonate positively with me. But I would like to point out that a downy feather also has a central string. The difference between the two types of feathers is due to the fact that the central string in the downy feather is not developed.
From Chalk,
The two explanations you put forward are not perfect. I suggest the following wording:
1. The dinosaurs began to develop feathers for other purposes, then in a rapid process, an "evolutionary leap" (what is a few millions out of billions of years of evolution?), a group of them underwent changes that allowed them to fly, and they will be called birds.
2. There were dinosaurs that developed the ability to fly (they were never found, since the transition process was "quick" and not many details of intermediate stages remained), then in some of them it atrophied (for example, Eutyranus) but the feathers remained.
There are several reasons for the persistence of a feature. Here are two: a) Another beneficial use was found for the feature. b) Since the feature does not interfere (as mentioned, a feather is a simple structure that does not require a "heavy" genetic code), it was not deleted.
Evolution is one of the most vibrant scientific branches. It is full of hypotheses and counter-hypotheses, and new findings are frequently discovered that have the power to overturn solid theories based on them. Therefore I do not completely rule out any explanation.
The evolution of feathers.
The most common explanation is that the first feathers evolved from scales. All reptiles have developed scales or scales in a recessive state, this is because reptiles evolved from fish (many fish had scales for a long time).
The simplest form of feather development from scales is the splitting of the scales into strips that all come out of the "root" of the scales, that is, splitting from the point where the scales are attached to the body. These are downy feathers, not the developed feathers of birds. The feathers (on the wings) of today's birds are feathers with a central string, when there is usually a split from the central string into secondary strings, there is another split from the secondary strings into "hairs". Most birds have (in addition to the string feathers) also downy feathers, for example in the neck, belly and chest area.
The development of a downy feather from a scaly does not require major evolutionary changes because to begin with a scaly is not perfect and can be grooved in its outer part, therefore the splitting process is the creation of deeper and deeper grooves until strips are formed. This evolutionary process (gradually deepening indentation) is well known in botany: for example in the different species of acacia trees (some acacias have more indented leaves, some have less indented leaves, some acacia leaves are not indented at all).
What is the reason why feathers were formed in dinosaurs? The most likely reason is thermal insulation (heat or cold), this allows for a longer activity time during the day or flexibility in choosing suitable territories for living. The claim that feathers evolved for the purpose of sexual decoration is completely improbable, since the evolutionary effort is not worth the result (there are many "cheaper" ways of decoration in terms of evolutionary effort, for example skin pigmentation or vocalization).
Why do large living animals have feathers? It is possible that this is inherited from the time when the ancestors of the animals were small (for example: the mammoths were hairy despite their size, there was no benefit to their hairiness when they were big, the mammoths' hairiness could be inherited from their small ancestors who needed the hairiness to maintain thermal insulation. The origin of the entire group of "elephants" was small animals that kept growing). It is known that all large dinosaur species were originally small, they gradually grew larger during evolution.
The new dinosaur found with feathers probably belongs to the species of dinosaurs where the feathers are downy. Thus its connection to modern birds is loose (modern birds have mostly stringy feathers).
To Yuval,
First, feathers are really not that simple a story. The feather is a living and growing protrusion of the epidermis outside of it, unlike fur which is a dead lump that is secreted from the epidermis. The fact that it is not mathematically "complicated" still does not mean that it is easy to produce.
Regarding aviation - feathers are really not enough to fly. In order to fly, an extraordinary lightness of the body is required (do you know that there is no bird that flies today that weighs more than 14 kg as an adult?!), highly developed chest muscles, changes in the structure of the arms, changes in the bones, etc.
So what do you think is a simpler and more reasonable explanation:
1. The dinosaurs began to develop feathers for other purposes, then in a gradual and slow process a group of them underwent changes that allowed them to fly, and you will be called birds.
2. There were dinosaurs that developed the ability to fly (which have never been found), then in some of them it degenerated (and those are found recently) and then from them the ability to fly in birds developed again.
post Scriptum
In case you're about to say that, pterosaurs aren't dinosaurs.
From Chalk,
Although the structure of a feather looks complicated and complex, it is actually a recursive tree whose development may be extremely rapid both in the development of the individual (from the chick's down to the mature chicken's feather), and in the evolution of the avian class. It is indeed probable that the feather preceded aviation and was initially used for purposes such as those you mentioned, but it is also probable that aviation developed shortly (in evolutionary terms) after that.
My opinion, as mentioned, is that growing feathers is simple and does not require much investment, and thus it is possible to find feathers on the bodies of birds that have given up flight and did not bother to get rid of them. Therefore, I do not rule out the possibility that the feathers of the Hyotyranus are degenerate remains of flight feathers in its ancient ancestors.
for Jubilee
Explanation is not that the beginning of the development of feathers in birds is related to flight. Small and undeveloped feathers cannot be used for flight, and flight requires many more features, so the hypothesis is that feathers were used in the beginning for heating/courtship display, and only later began to be used for movement, whether for acceleration in running or for gliding, and only then for flight.
This dinosaur that was found is one of the "pioneers of feathers", but at such an early stage there is no reason to believe that these feathers are a degradation of developed feathers that were used for flight.
*
Recently, the recognition that the birds are the descendants of the dinosaurs is expanding.
The popular explanation is that the beginning of the development of feathers in the ancient ancestors of the birds is related to flight, and that the feathers also survived in the bodies of the birds that gave up flight in favor of large body dimensions.
The same reasoning can be applied to the dinosaurs as well
Just as today the birds that gave up flight kept their feathers, the dinosaurs that gave up flight hundreds of millions of years ago also kept their feathers.
Recently, the recognition that the birds are the descendants of the dinosaurs is growing.
The popular explanation is that the beginning of the development of feathers in the ancient ancestors of the birds is related to flight, and that the feathers also survived in the bodies of the birds that gave up flight in favor of large body dimensions.
The same reasoning can be applied to the dinosaurs as well
Just as today the birds that gave up flight kept their feathers, the dinosaurs that gave up flight hundreds of millions of years ago also kept their feathers.
Not all paleontologists agree.
An interview with paleontologist Alan Peduzia
http://discovermagazine.com/2003/feb/breakdialogue
Body heating is not necessarily the main reason for feathers: it is very likely that it was an important part of sexual selection and therefore the size of the dinosaur has no meaning