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Were dinosaurs reptiles? Are birds reptiles?

 
 
oralloy
 
  1  
Reply Thu 3 Jul, 2008 12:37 am
oralloy wrote:
rosborne979 wrote:
oralloy wrote:
We do have common ancestors with reptiles, but synapsids are not reptiles. Our lines diverged before reptiles evolved.

What is the common ancestor we share with reptiles?


I think it would have been an amphibian of some sort.


http://en.wikipedia.org/wiki/Amniote



oralloy wrote:
rosborne979 wrote:
Does a fossil of the creature exist?


I don't think so, but every now and then I hear on the news that someone has found a fossil of something "close" to the last common ancestor.


http://en.wikipedia.org/wiki/Casineria
0 Replies
 
dadpad
 
  1  
Reply Thu 3 Jul, 2008 03:46 am
This may be of interest.

Dr John Long is a local and I heard him speak recently.

380 million year old fishes found with unborn embryos.

In 2005 Museum Victoria's expedition to the Gogo fossil sites in north Western Australia, lead by Dr John Long, made a swag of spectacular fossil discoveries, including that of a complete fish, Gogonasus, showing unexpected features similar to early land animals.
oday the team announced its latest discovery: a remarkable 380 million year old fossil placoderm fish with intact embryo and mineralised umbilical cord.

http://museumvictoria.com.au/about/MV-News/2008/Mother-fish/

This link is also iteresting though unrelated to the topic
http://museumvictoria.com.au/about/MV-News/2006/Ancient-Gogonasus-advances-evolution/
0 Replies
 
farmerman
 
  1  
Reply Thu 3 Jul, 2008 04:22 am
THE superorders of reptiles are in atransition as more genetic information is gathered.
The present superorders includes everything reptilean [Eoapsidia (proposed new classification made to contain Casinerea, Anapsidia,Synapsidia,SynapsidiaII, and Diapsidia]
Many of these superorders are merely convenient niches from fossil evidence (or in the case of the Therapsids and Theriodonts-from inferred lifestyles as extracted from fossil dentition and body suspension).

Aves is a clear break with the reptilean dtructure , yet so many of the early "true" birds retain as many as 20+ reptilean features . I think that , with newer genetic information on ancient bird groups such as ratites and living diapsids, well see an entirely new classification system.


The problem we have with "mammal like reptiles" is that, while they may be mammal like in inferred structures (such as upright theropod suspensions), they exist in the fossil record in a very few areas right along with some "Almost" mammals(cynodonts which were warm blooded) of approximately the same age. The fossil record needs some infilling with new finds and these finds are busily being dug in the sands of the upper Permian .
0 Replies
 
spendius
 
  1  
Reply Thu 3 Jul, 2008 11:10 am
fm wrote-

Quote:
I think that , with newer genetic information on ancient bird groups such as ratites and living diapsids, well see an entirely new classification system.


Oh! The jobs. The funds. The buildings. The reserved car parks. The senior dining rooms. The teak cabinets. The computers. The titles. The strutting. Endless fun beckons.

Create your own cushy job at the cutting edge of Veblen's "waste=status" principle. Eldorado beckons with a flick of the wrist.

Magical really. It makes ros's FSM look like a confused mule.

I'd bet fm signs his name with a flourish.
0 Replies
 
farmerman
 
  1  
Reply Thu 3 Jul, 2008 12:14 pm
Actually , I detest paleontology. It is the "stamp collecting" of the geological sciences. However, the systematics within it and its ever modifying sub discipline of cladistics and paleoecology are all necessary arts so that guys like me can use the data that spendi ignorantly accosts ,,to go afield to do prospecting and minerals exploration.

Maybe spendi wants his brewery swill to be served up from wooden kegs, subject to quick spoilage and molds. Aluminum ore exploration is an example of how paleontology provides some key finds in the discovery and mining of minerals like gibbsite and boehmite which make up the aluminum layers of the rock "bauxite".

However, Ill let spendi quietly slip under the table as he tries to come up with comments that can validate his contribution_ free life. SHHH, lest we arouse him from his torpor.
0 Replies
 
spendius
 
  1  
Reply Thu 3 Jul, 2008 02:19 pm
I was only passing comment on the idea of initiating an "entirely new classification system".

What evidence have I provided that the modern John Smith's Extra Smooth production and distribution processes are anything but sheer perfection or that I wish to return to wooden kegs, spittoons and flat sour beer?

I think you have a straw man on your plate there old boy.

Doesn't prospecting and discovering substances we can exploit for binging purposes accelerate the destruction of our environment? A lot of scientists are saying so.
0 Replies
 
oralloy
 
  1  
Reply Thu 3 Jul, 2008 04:48 pm
farmerman wrote:
The problem we have with "mammal like reptiles" is that, while they may be mammal like in inferred structures (such as upright theropod suspensions), they exist in the fossil record in a very few areas right along with some "Almost" mammals(cynodonts which were warm blooded) of approximately the same age. The fossil record needs some infilling with new finds and these finds are busily being dug in the sands of the upper Permian .


I don't see the problem. It is true that the cynodonts were on the path that led to the mammals, and the therocephalians and gorgonopsids died out, but they were clearly all on the pelycosaur/therapsid/mammal branch of the tree of life.

The name "mammal like reptiles" needs to be done away with though. As synapsids, they are not even close to reptiles. I like the term "proto-mammal" for pelycosaurs and therapsids -- it doesn't confuse them with reptiles, and it makes it clear what their significance is.
0 Replies
 
oralloy
 
  1  
Reply Thu 3 Jul, 2008 04:51 pm
spendius wrote:
Oh! The jobs. The funds. The buildings. The reserved car parks. The senior dining rooms. The teak cabinets. The computers. The titles. The strutting. Endless fun beckons.

Create your own cushy job at the cutting edge of Veblen's "waste=status" principle. Eldorado beckons with a flick of the wrist.


Shocked Surely you don't object to the advancement of science???
0 Replies
 
farmerman
 
  1  
Reply Thu 3 Jul, 2008 06:58 pm
oralloy, It would be like having an archeopteryx and a late feathered reptilian in the same strat. Its a problem because many derived structures show up on proto mammals and ictideosaurs, The early guys like Colbert and Romer were the "gatekeepers" of what became the cladistics of mammals v reptiles. The real problems are that, in th literature (not the internet) there are ongoing disagreements with what is a mammal. So to have mammals and reptilian fossils lie together, we have to look farther back for real derived species.
Similar to birds.
0 Replies
 
farmerman
 
  1  
Reply Thu 3 Jul, 2008 07:38 pm
oralloy
Quote:
The name "mammal like reptiles" needs to be done away with though. As synapsids, they are not even close to reptiles. I like the term "proto-mammal" for pelycosaurs and therapsids -- it doesn't confuse them with reptiles, and it makes it clear what their significance is.

You are free to use whatever terminology you wish, but in strict sense, youd be incorrect.The skull structure of synapsida include single orbital and double orbital skull structures .Which is why most paleontologists who do evo/devo work, consider them to be reptiles. Ill look at my "Treatise" volumes on mammalian evolution and pull out those "questionable fossils" of the late Permian which are classed as mammals .
0 Replies
 
spendius
 
  1  
Reply Fri 4 Jul, 2008 06:41 am
oralloy wrote-

Quote:
Surely you don't object to the advancement of science???


Sometimes I do. When Science goes into politics for example.
0 Replies
 
kolembo
 
  1  
Reply Sun 7 Aug, 2011 09:59 am
@rosborne979,
Gee Whizz.

It's still not clear.

MY problem isn't with who lays eggs and who doesn't, it's with who's warm blooded and who isn't.

Reptiles are cold blooded. They need sun, they true-hibernate.

Birds I thought were like mammals...warm blooded - migrate rather than hibernate.

Dinasaurs I thought were like reptiles - cold blooded but I find now that they migrated...like birds.

Science leans towards Dinasaur/Bird relationship

I now do too - so then, Dinasaurs are warm blooded?
rosborne979
 
  2  
Reply Sun 7 Aug, 2011 11:22 am
@kolembo,
kolembo wrote:
I now do too - so then, Dinasaurs are warm blooded?

Yes. Many were warm blooded, probably a lot like birds because they pretty much were birds.

But the term "Dinosaur" is a very broad and imprecise term. Some things with people call dinosaurs were actually reptiles, and other branches of dinosaur evolution may not have been warm blooded.

Also, there's no reason to think that dinosaurs were limited to the biothermal patterns we see today. They may have had unique biothermal control mechanisms which don't even exist today.
0 Replies
 
 

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