Did modern birds evolve from ancient reptiles?

[masonswanson]

did they i mean i saw this thing on the science channel about it and thought it was pretty cool

[Tormod]

Yes, birds are the descendants of the dinosaurs.

 

Here is an interesting look into this:

http://www.ucmp.berkeley.edu/diapsids/avians.html

[Queso]

i heard there have been recent arguments that birds were actually around when the dinosaurs also. i have no sources and maybe i have no idea what i'm talking about, it was just something i heard somewhere.

[Tormod]

Well, since you have no sources and no idea what you're talking about...maybe you should try to *find* some sources? :cup:

 

The dinosaurs ruled the world for a _very_ long time. So the early birds did evolve while there were still other dinosaurs around.

 

Here is a source for you:

http://www.dino-web.com/birds.html

[alxian]

tormod you stated a theory as though it was immutable fact.. when there are dozens of accounts that suggest our dinosaur theory is flawed, our cometary impact extinction theory is only gaining steam by way of factual proofs like the Yucatan crater but not everyone believes in it.

 

your post seems to state those theories as fact and almost dismisses any other possibilities.

 

have you read (about) the summerian story of creation? it maintains that an unknown planet was the origin of saurians and such (i believe though they have it that life also developed here) our planets collided and a sharing occured.

 

in case of such a planetary collision i've always wondered if life could survive and when the waters of the two worlds mixed they could have shared life forms (not to mention the oddity of the oversupply of water on earth).

 

that is to say if to planets thriving with life collide does that life in the least traumatized areas, and the hardiest creatures like bacteria survive the collision and persist on its new home?

 

unfortunately the story is just that, without that second body and a proper orbit to calculate we cannot say for certain if and when such a collision occured.. there is just far too much evidence for it though for it all to be a coincidence (all the weirdness) like what if pangea wasn't the only land mass? what if the other side of our cleaved world had life on it? and the waters of tiamat (if the planet was bigger, that would account for the excess water on a smaller cleaved world) didn't cover earth as fully as they do now? those underwater pyramids found all over the world may not have been underwater when they were built and used.. but that would mean man was around during that collision event.. unsurprisingly there are myths that maintain humans have always existed on earth in one form or another, one i like is a bbc article stating that humans number in the thousands (as opposed to the billions of today) what if throughout that long time humans (our distant but still intelligent ancestors) interbred with similar species (apes) to form modern homosapiens?

 

http://www.dinosauria.com/jdp/impact/impact.htm

http://www.clarifyingchristianity.com/archaeopteryx.shtml < sorry orb..

http://www.ideacenter.org/contentmgr/showdetails.php/id/1275 < mildly supports orb.. :cup:

 

gravity and extinction

http://frederic.malmartel.free.fr/Fin_des_dinosaures/eedinosaures3.htm

http://www.dinox.org/english/cmt2000a.htm

 

well unfortunately unless i tear out and scan the time life article i won't get the article up here, the gist of it was that gravity on earth now means animals like flighted saurians could not fly, they would be too heavy, a bigger less dense planet would easily account for these animals, they would have shrunk into modern bird sizes as gravity increased, similarly as pangea broke apart their habitat would have shrunk causing dwarfism.

 

there are simply too many stories and not enough hard facts. besides the fact science won't accept extraplanetary life theory without a boiling cauldron with primordial soup welded to the side of it and human footprints around it on nibiru (or one of its moons depending on the variation of the story you want prefer), similarly fossils on the moon (from earthlike creatures) would raise many unwanted questions (besides politics what could have scared away the US gov't for 30+ years?), leaving mars alone for another discussion (which also had liquid water flowing and possibly entrie seas). then there is venus... the toxic clouds mean surface life would have a hard time today (but the tops of the clouds exhibit anomolous readings) and the clouds didn't always clouds venusian skies, earth and venus may have been true twins.. i forget the stats but the venusian atmosphere if condensed covers the billiard ball surface entirely (or almost with liquids, perhaps water) (also noting that the surface is only smooth because of the crushing atmospheric pressure and heat) (i'd bet my kingdom that fossils will be found on venus and mars (and possibly within some of the larger belt objects, assuming of course that the belt is a pulverised planet)..

 

rats.. my shift starts in minutes.. enough for now.

[Fishteacher73]

Axlian, not to dismiss your theories, but the evolution fron dino to bird is pretty much fact. Granted there is a lot of debate over WHAT killed the dinos, the link of avians and dinos really is not This also occured before the extinction of the dinos. There have been "true" bird fossils found from the late Cretaceous, benieth the KT boundry (ie older than the generally accepted threshold of dinos).

[pgrmdave]

At what point did birds split from dinosaurs? Are there any known dinosaurs that displayed bird characteristics? I know that Nat'l Geographic ran an article a few years ago about a dinosaur with feathers that later turned out to be a hoax.

[lindagarrette]

At what point did birds split from dinosaurs? Are there any known dinosaurs that displayed bird characteristics? I know that Nat'l Geographic ran an article a few years ago about a dinosaur with feathers that later turned out to be a hoax.

The web site referenced by Tormod earlier in this thread had the answers to your questions.

[Fishteacher73]

Dino's are split into two groups, ones w/ bird-like hips(Ornithischia) and others w/ lizard-like hips (Saurischia). There may have been hoaxes in the past about feathered dinos, but there are real fossils today to support this. (Archaeopteryx if I recal).

[Fishteacher73]

Although it should be noted that reptiles and dinos split a long time ago and modern reptiles are from this split, and not an off-shoot of the dinos.

[motherengine]

Axlian, not to dismiss your theories, but the evolution fron dino to bird is pretty much fact.

 

how can something be 'pretty much fact'? birds have many similarities to reptiles but does this mean they descended from reptiles?

[Tormod]

tormod you stated a theory as though it was immutable fact.

 

No, I did not. I stated a currently accepted scientific theory and backed it up with a source. that is not "immutable fact".

 

besides the fact science won't accept extraplanetary life theory without a boiling cauldron with primordial soup welded to the side of it and human footprints around it<snip>

 

I am not aware of any "science" that is claiming that extraplanetary life came about in a boiling cauldron.

 

Anyway, this is off-topic for this thread which concerns dinos and birds.

[MortenS]

how can something be 'pretty much fact'? birds have many similarities to reptiles but does this mean they descended from reptiles?

 

For a scientist, when there is overwhelming evidence that point in one direction, and nothing that points in another direction, theories have the tendencies to be viewed as pretty much fact, until contradictionary evidence should turn up. So far, there have been no evidence that birds are closer related to lets say, mammals or amphibians than reptiles.

 

Both mammals and birds are both descendants of reptiles. Mammals originated from synapsids, more specifically the Therapsids.

 

Birds are of a much later origin, most closely related to the superorder Archosauria, which includes Crocodylia, Pterosauria and the two dinosaur orders Saurischia and Ornitischia.

 

Al of these relations was first established based on the similarity of bones.

 

Then came the advent of DNA technology. Looking at the mtDNA (16S DNA in particular) of birds and various reptiles, it turned out that birds, in all the most parsimonious phylogenetic trees, came out most closely related to the crocodiles, our only living archosaurian reptiles.

 

This is a very strong piece of evidence, independently corroborating the evidence from comparative anatomy between birds and dinosaurs fossils.

 

The vast majority of paleontologists now hold on to the theory that birds descended from Theropods. There is a small group of paleontologists that hold the view that theropods and birds are descendants of thecodonts, and that the similarities between theropods and birds are the result of convergent evolution. None of these competing theories are challenging the reptilian origin of birds.