Re: paleonet Origin of birds

[Carl Mehling <cosm@xxxxxxxx>]

It's not exactly bad naming. The names were meant to imply a general 
appearance, not relatedness. Just by chance, it is the ones that were not 
named bird-hipped that turned out to be the ones related to birds.

At 09:49 AM 4/12/2005, you wrote:
>Everyone seems to agree on the matter of relationship, but this question 
>needs a little more explanation for the non-specialist and especially for 
>students without any background. People who teach will be faced with 
>answering similar questions from students and a summary of basics would be 
>appreciated.
>
>If birds have a saurischian hipped skeletal structure, is the 'bird 
>hipped' skeletal structure of the onithischians a case of bad naming, or 
>has the hip structure of the saurischians changed significantly over the 
>course of evolution?
>If it is a case of bad naming, what was the reason for the poor choice of 
>terms?
>
>Note that this question does not relate to determining relationship, it 
>relates to understanding the appropriateness of names and the reason for 
>the confusing names that have been used in discussing the hip structure of 
>group names of dinosaurs and birds. A short answer to this type of 
>question will quickly satisfy students and will make learning more than 
>simple memorization of terms.
>
>  T. Yancey
>
>
>
>
>>You've got it essentially correct. Birds are descendants of small 
>>theropods making them dinosaurs themselves. Theropods are saurischians 
>>but the "lizard hipness" of the entire group was not meant to imply 
>>relatedness, just similarity. The very birdlike non-bird theropods 
>>weren't well known at the time of the origin of the word saurischian and, 
>>as it turns out, their hips are more birdlike than the ornithischians.
>>
>>-Carl
>>
>>At 09:58 AM 4/11/2005, you wrote:
>>>If I understand it correctly, birds are thought to be closely related 
>>>(derived from or cousins with) the small theropod dinosaurs.  But 
>>>theropods are part of sauriscia, the "lizard hipped" clad.  Are ave hips 
>>>really like ornithicia ?  Is there a disconnect here, or are my 
>>>understanding of dinosaur clads incorrect.
>>>
>>>(Forgive my spelling)
>>>
>>>Am I being to simple minded here ?
>>>
>>>
>>>Al McCarrick
>>
>>Carl Mehling
>>Fossil Amphibian, Reptile, and Bird Collections
>>Division of Paleontology
>>American Museum of Natural History
>>Central Park West @79th Street
>>New York, NY  10024
>>(212) 769-5849
>>Fax: (212) 769-5842
>>cosm@amnh.org
>
>

Carl Mehling
Fossil Amphibian, Reptile, and Bird Collections
Division of Paleontology
American Museum of Natural History
Central Park West @79th Street
New York, NY  10024
(212) 769-5849
Fax: (212) 769-5842
cosm@amnh.org