If birds evolved from dinosaurs and ARE reptiles?

Please do yourself a favor and ignore anything Cal says about dinosaurs and birds. He's a member of the Feduccia group, and has chosen to follow his beliefs rather than the evidence. You will be better off reading about this for yourself.

You appear to be somewhat confused about the whole thing, though.

First of all, no matter what you may think about dinosaurs and birds, mammals are a different group from reptiles. Mammals are defined by certain characteristics that they share - mainly the possession of hair, and mammary glands in female mammals. No other group of animals shares these characteristics along with the other defining characteristics of the higher-level groups such as amniotes and synapsids (you'll need to look those terms up).

Laying eggs means nothing - fish lay eggs; butterflies lay eggs.

Furthermore, I don't know where you heard that any scientists are claiming that dinosaurs are mammals, warm-blooded or otherwise. Dinosaurs are archosaurs, a line of animals that split off from the line of reptiles that led to mammals a long, long time ago. Dinosaurs share a number of characteristics with each other - most notably, a fully erect stance, which is based on several specialized modifications of the legs. No other group of animals shares the defining set of characteristics with dinosaurs (other than birds, of course). Dinosaurs are definitely not mammals; they do not have the same set of characteristics that define mammals. We may not be able to tell whether any extinct dinosaur had hair or mammary glands, but the basic skeletal structure indicates that they are quite separate from the line of synapsids that led to mammals - all archosaurs are diapsids, including dinosaurs. This means they have a skull bone assembly that is significantly different from the skulls of mammals and their relatives.

The question of 'warm-bloodedness' is still a matter of discussion, but then, the whole idea of 'warm-blooded' and 'cold-blooded' is a messy one. Tunas are 'cold-blooded' fish, but they regulate their internal temperature and maintain a constant temperature without any outside source of heat. There are plenty of other 'grey-area' animals, but this is already too long - look up poikilothermic, homeothermic and warm or cold blooded and start reading.

To briefly address the question of birds and dinosaurs, and again, you will want to read up on this, rather than just taking my word for it: when you decide on a set of characteristics that define modern birds, you find that these characteristics are found in extinct dinosaurs as well (at least insofar as we can find them in fossils). No other group of animals shares these characteristics, which include certain skeletal structures such as the wishbone and the leg modifications for erect stance, and feathers. This is a very simplified answer, and there is a great deal more to this discussion, but the weight of the evidence is pretty indisputable. That has never stopped anyone from arguing about anything, however - there are still people who claim that there is no such thing as evolution.

Birds evolved from dinosaurs we can see that and platypus are mammals the first true mammals layed eggs only later did they give birth.

Your question doesn't make sense...

BUT

If you think about it, dinosaurs had to use large amounts of energy to catch prey and keep from being eaten. Thus, being warm blooded could be beneficial to them. It doesn't mean they were mammals though, they still laid eggs. Additionally, it can't be proven for sure that they were warm blooded.

Although birds and other reptiles do share ancient ancestors, over the millenia divergent evolution lead to distinctive differences between the two groups.

Dinosaur cross cut bones show the same interior cell structure as warm blooded mammals, not cold blooded reptiles.

Mammals and birds evolved warm-bloodedness, or endothermy, independently of one another. In addition to warm-bloodedness, mammals are distinguished from stem-group amniotes by the evolutionary novelties of hair, lactation, a four-chambered heart, diphyodonty, and heterodonty. The other branch of the amniotes is called the Sauropsida, which comprises the reptiles and birds. The sauropsids are distinguished from the stem-group amniotes by the evolutionary novelties of color vision and beta-keratin. In addition, birds are distinsguished from their fellow sauropsids by the evolutionary novelties of flight, feathers, and a four-chambered heart.

Note that while both birds and mammals exhibit the traits of endothermy and a four-chambered heart, they evolved those traits independently of one another. In mammals, it is the right ventricle which pumps blood to the lungs and the left ventricle which pumps blood to the rest of the body. In birds that pattern is reversed.

In theory of the creation ,there should be land and sea .As starting life shape ( bacterial ).Bacteria can grown inland and in the water .This it make two type of the creatures .Water creatures and land creatures .Reptilian are most close in range of the water creature ,which reach to the land cause of circumstances .Again circumstances it cause they choose (natural selection)to be egg layers or mammals. Again circumstances it cause to they choose to fly or they walk or they run .Shape of skeleton it determinate the term of the change from reptilian to bird ,mean that those short hands after many years it turn to the wings and fly .If you take look to a eagle baby you will see that they are look like dinosaur without feeder ,process of the growing to an adult is exact as change that has been made ,but is very faster than it was .A dinosaur may take million years to look like a today eagle ,but a baby eagle it take 2-3 mount to look like an eagle .This process is kind of difficult to understand cause of length of the time ,and we do not know exactly what it is happen that natural selection it make change .Some believe on mutation of the cell for survive it cause to change happened. Some believe that survived creature up to the circumstances of life naturally select to change and this change for the inland creature is more than sea creatures .Couse condition of the life on the inland is more under the circumstances than the sea .Mean air, grass,, food, ,weather at inland are faster change than the sea. So you see that fishes shape does not change that much ,but mammals and birds have extreme change during circumstancing of the inlands.

-Birds are not reptiles.

-Scientists do not keep insisting that dinosaurs were mammals.

You have no idea what you're talking about.

Very good question. Basically, some scientists who have a religious belief that birds evolved from a dinosaur have painted themselves into a corner, and they find themselves believing things that are self-contradictory.

Since all living birds are endotherms ("wam-blooded"), these scientists argued long ago that so were dinosaurs. They did not say that dinosaurs were mammals, but they nevertheless believed that dinosaurs were endotherms. The idea that dinosaurs were endotherms have been soundly refuted, when a group of scientists got together and did some research on the topic and published their findings in the book "A cold look at warm-blooded dinosaurs." The book has been out of print for a while, but you can still find it in a well stocked university library or from Amazon.

http://www.amazon.com/Cold-Warmblooded-Dinosaurs-s...

The book concluded that dinosaurs were gigantotherms, meaning their blood was indeed warm, but they rely on their large size and a warm climate (warmer than today's climate) to stay warm. As somebody put it, an endothermic dinosaur would have cooked itself from the inside out. A dinosaur as big as T. rex, for example, would have suffered heat stroke easily if it were endothermic. Sure enough, many dinosaurs, including T. rex have been found with growth rings in their long bones, which indicated that their growth rate is different seasonally, just like modern living ectothermic reptiles. In fact, even some ancient birds, such as Archaeopteryx, had growth rings in their long bones, indicating that they too were ectotherms, not endotherms.

Since ancient birds were ectotherms, it would not have presented a problem for the believers of the dinosaurian origin of birds, because an ectothermic dinosaur evolving into an ectothermic bird would not present any difficulty. However, these scientists have, for the past 15 years or so, also embraced the idea of "feathered dinosaurs." Since dinosaurs, by definition, did not fly, they have also had to find a reason for dinosaur feathers. The reason they came up with, is that these feathers were used as insulation for warm-blooded dinosaurs! So, the belief that dinosaurs had feathers basically painted the believers into a corner, and they have no choice but to believe that dinosaurs, at least the small ones, were endotherms. Unfortunately, the enthusiasm for feathered dinosaurs was so overwhelming that people soon starting putting feathers on all types of dinosaurs, both large and small, and they forgot that large dinosaurs like T. rex cannot possibly be endotherms and not cook themselves from the inside out. Needless to say, the theory that birds evolved from dinosaurs is a big mess, because scientists who have such a belief have to embrace evidence that contradict each other.

A final example of such self-contradiction was given by Alan Feduccia in his recent book: Riddle of the Feathered Dragons, in which he pointed out that in a meeting of paleontologists in the 1980's, two votes were taken. The first was whether birds evolved from a dinosaur, and the second was whether birds evolved flight from the tree down or from the ground up. A majority of paleontologists voted for the theory that birds evolved from a dinosaur and a majority also voted that birds evolved flight from the tree down, apparently not realizing that there was no tree-climbing dinosaur, so both theories cannot be true. To this date, scientists have not found any tree climbing dinosaurs, so the next best thing they can do is to claim that some fossils, such as Microraptor and Anchiornis, which are almost certainly birds, and which have flight feathers sticking out of their hindlimbs, were in fact feathered dinosaurs. Unfortunately for the believers, someone forgot about self-contradiction because they published a paper a few months ago that shows ancient birds like Confuciusornis, Sapeornis and Yarnornis also have hindlimb feathers. So, how does one draw the line between birds and dinosaurs if they are both small, feathered and they both have 4 wings?. Why are some animals with 4 wings identified as birds but some animals with 4 wings are identified as dinosaurs? It is a question that they will have trouble finding a convincing answer to, because they have painted themselves into a corner and they can only come up with stupid answers. One silly explanation is that the 4 winged, feathered dinosaurs were using their wings for display, not for flight, but the 4 winged birds were flyers. If so, then these 4 winged, feathered dinsoaurs are the only examples of animals evolving wings for the sole purpose of display. Sounds as implausible as flight from the ground up, which was a theory that was voted down in the 1980s but which is still held by some paleontologists because they have painted themselves into a corner.

There is no medical proof to that theory so, who really knows.. They will argue black and blue on it so let them believe what they want and you decide what you think just don't write that in biology papers write the answers the expect from you which I guess is there ideals.