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Post by sbell on Jan 26, 2012 4:40:11 GMT
Think of 'pterosaur' as being at the same level as 'dinosaur'. Both groups are themselves united under a big clade (group), the Archosauria, which also contains crocodiles and their relatives. Also... Birds ARE dinosaurs! So Diplodocus is a bird? No one said dinosaurs are birds. They said that birds are dinosaurs. That's like saying eels are fish, so guppies must be eels (and yes, it is exactly the same). And Stoneage, I know you are an intelligent person who knows darn well that you're being a smart alec just to get a reaction. This is also known as 'trolling' in internet speak, and is generally considered inappropriate behaviour. But since we've known you here for so long, we also know it's probably just trying to be 'funny'. |
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Post by Horridus on Jan 26, 2012 18:17:11 GMT
Yes, and you're a bat! I think you might have swapped the order of the words in my statement...  |
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Post by sbell on Jan 26, 2012 18:20:53 GMT
Yes, and you're a bat! I think you might have swapped the order of the words in that sentence... I doubt it--it wouldn't work as, "a bird is a Diplodocus." |
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Post by Horridus on Jan 26, 2012 18:22:21 GMT
I doubt it--it wouldn't work as, "a bird is a Diplodocus." I meant my original statement - "birds are dinosaurs" - he obviously swapped it to "dinosaurs are birds"... Have edited my post to make it clearer. |
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Post by gwangi on Jan 26, 2012 22:10:12 GMT
I heard another one today. I was talking to a co-worker about that Disney movie "Dinosaur". I commented that lemurs did not live with dinosaurs. He replied that is was stupid for the movie creators to put lemurs in it if they didn't live with the dinosaurs. I went one with "well most of those dinosaurs didn't even live at the same time or in the same place. His reply was..."of course they lived in the same place, all the continents were joined together!" *Face palm*. I told him that the continents moved a great deal during the time of the dinosaurs and that by the time they died most were close to where they are now. Another friend chimed in "I wonder why the continents don't move anymore"...nuff said.
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Post by stoneage on Jan 27, 2012 3:07:07 GMT
I doubt it--it wouldn't work as, "a bird is a Diplodocus." I meant my original statement - "birds are dinosaurs" - he obviously swapped it to "dinosaurs are birds"... Have edited my post to make it clearer. The proper terminology is not birds are dinosaurs, but birds are non-avian dinosaurs. Other dinosaurs which are not birds are non-avian dinosaurs. Technically birds are considered reptiles. |
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Post by gwangi on Jan 27, 2012 4:08:21 GMT
I meant my original statement - "birds are dinosaurs" - he obviously swapped it to "dinosaurs are birds"... Have edited my post to make it clearer. The proper terminology is not birds are dinosaurs, but birds are non-avian dinosaurs. Other dinosaurs which are not birds are non-avian dinosaurs. Technically birds are considered reptiles. This makes no sense but I assume you just made a mistake and meant to say "birds are avian dinosaurs". Regardless, saying that birds are dinosaurs is no less valid. We don't call bats "avian mammals" and the rest of mammalia "non-avian mammals" do we? Maybe you do. And of course birds are reptiles because dinosaurs are reptiles and birds are dinosaurs. |
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Post by sbell on Jan 27, 2012 4:10:44 GMT
I meant my original statement - "birds are dinosaurs" - he obviously swapped it to "dinosaurs are birds"... Have edited my post to make it clearer. The proper terminology is not birds are dinosaurs, but birds are non-avian dinosaurs. Other dinosaurs which are not birds are non-avian dinosaurs. Technically birds are considered reptiles. Sorry man, you're splitting hairs in odd ways here. Birds are part of the Dinosauria, which is part of Reptilia. So no matter what, they are dinosaurs. When qualifiers (avian vs non-avian) are used, it is to be taxonomically clear about what kind of dinosaur is being discussed. This is just BANDit double-speak. |
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Post by Horridus on Jan 27, 2012 18:30:08 GMT
The proper terminology is not birds are dinosaurs, but birds are non-avian dinosaurs. Other dinosaurs which are not birds are non-avian dinosaurs. Technically birds are considered reptiles. Birds are considered reptiles because they're theropods, which are dinosaurs, which are archosaurs, which are diapsids, which are sauropsids (reptiles). The terms 'avian' and 'nonavian' dinosaur are used because birds are the only dinosaurs that are still extant. Therefore, it can be helpful to talk about them separately in such a way (eg. all the 'NONAVIAN' dinosaurs went extinct 65m years ago). In the sentence 'birds are avian dinosaurs', the word 'avian' is redundant - of course birds are avians. |
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Post by Seijun on Jan 27, 2012 18:39:10 GMT
. (mistake post)
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Post by arioch on Jan 27, 2012 22:29:29 GMT
The proper terminology is not birds are dinosaurs, but birds are non-avian dinosaurs. Other dinosaurs which are not birds are non-avian dinosaurs. Technically birds are considered reptiles. Birds are considered reptiles because they're theropods, which are dinosaurs, which are archosaurs, which are diapsids, which are sauropsids (reptiles). The terms 'avian' and 'nonavian' dinosaur are used because birds are the only dinosaurs that are still extant. Therefore, it can be helpful to talk about them separately in such a way (eg. all the 'NONAVIAN' dinosaurs went extinct 65m years ago). In the sentence 'birds are avian dinosaurs', the word 'avian' is redundant - of course birds are avians. The whole birds being reptiles thing is so messy to explain that it would be probably better if we just stop considering dinosaur reptiles. They´re just too far from the original definition of what a reptile is ( cold blooded, dim witted and bow-legged scaly animal). Aren´t we working with a classification based on a misconception? The first discovered dinosaurs were thought to be nothing else than a bigger and clumsier version (although Knight begged to disagree on that) of modern lizards , hence their classification under reptilia. This have remained unquestioned for decades despiting all we have learned about them, and its one of the reasons why so many people have such a hard time accepting feathers on dinosaurs, or birds being dinosaurs (dont even mention birds being reptiles if you don´t want jaw-dropping reactions) Holtz and other experts think they should fall under sauropsids, and nothing else. Although considering how variable the kind of metabolism, integument or even behaviour seems to be within dinosauria, this remains a really complex subject. |
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Post by gwangi on Jan 27, 2012 22:48:53 GMT
If you remove dinosaurs from reptiles you would also be forced to remove crocodilians which probably would not rub well with most people.
I must say though that your definition of Reptilia is...interesting to say the least. Reptiles are classified as such because they lay shelled eggs, have a scaly body covering and are cold blooded. Leg posture and intelligence have nothing to do with it. Birds meet those requirements with the exception of one and dinosaurs also meet those with the possible exception of one. The same goes for the rest of the Archosaurs including Pterosaurs and Crocodilians and the later clearly meets all the requirements. So what do we do? Tear the class Reptilia apart or simply alter the definition of the word?
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Post by arioch on Jan 27, 2012 23:03:38 GMT
Well, its not "my" definition of reptilia...but what pretty much everyone have in mind (or used to) when thinking of reptiles. Even some experts. That´s why its problematic.
On the other hand: platypus lay eggs. Ichthyosaurs don´t lay eggs or have scaly integument , yet they are reptiles. Its not that simple.
I´m rather agnostic on this matter to be honest, but I think its worth to consider.
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Post by sbell on Jan 27, 2012 23:16:18 GMT
Well, its not "my" definition of reptilia...but what pretty much everyone have in mind (or used to) when thinking of reptiles. Even some experts. That´s why its problematic. On the other hand: platypus lay eggs. Ichthyosaurs don´t lay eggs or have scaly integument , yet they are reptiles. Its not that simple. I´m rather agnostic on this matter to be honest, but I think its worth to consider. Shelled eggs are plesiomorhpic to basal amniotes--this would include the line that lead to mammals, and the separate line that lead to 'reptiles' in the true sense. The separation is based on the primitive conditions of the skulls. The problem is that people who don't really understand--or haven't actually looked it up--can still throw out whatever they think, and the expectation is that they should be afforded equal value in terms of correctness. Their opinions are not equal. Sorry. Mammals are part of the synapsid lineage, a sister group to the sauropsida. Both of those groups share a common ancestor. Period. Dinosaurs are a reptile. Birds share a common ancestor within the theropoda, which is within the dinosaurs. They are therefore dinosaurs. Period. Enough of this nonsense already. Unless this is meant to demonstrate the 'annoying' kind of misunderstanding. |
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Post by gwangi on Jan 27, 2012 23:23:48 GMT
We're not talking about re-classifying ichthyosaurs or monotremes, they are unrelated to dinosaurs and are not really relevent. I think most of us know that the entire class Reptilia is a mess anyway as is our entire system of classification. I'm merely saying...if you removed dinosaurs from Reptilia you would have to remove their closest relatives as well and that ain't happening. If anything public perception regarding reptiles as a whole needs to change more than anything else.
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Post by arioch on Jan 28, 2012 1:02:47 GMT
I wouldn´t disregard it so quickly when someone like Dr. Holtz seem to be supportive of the idea. But you´re right, all this is beyond the point of the thread. Lets move on. We're not talking about re-classifying ichthyosaurs or monotremes Right. Just tried to point out that laying eggs is not an obligate requirement for being classified as a reptile, like you said.  |
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Post by sbell on Jan 28, 2012 2:43:24 GMT
I wouldn´t disregard it so quickly when someone like Dr. Holtz seem to be supportive of the idea. But you´re right, all this is beyond the point of the thread. Lets move on. We're not talking about re-classifying ichthyosaurs or monotremes Right. Just tried to point out that laying eggs is not an obligate requirement for being classified as a reptile, like you said. Given recent DML postings, I am very suspect about the assumptions you are making regarding Holtz' opinions. Specifically, I am pretty sure he refers to birds as dinosaurs. |
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Post by arioch on Jan 28, 2012 3:16:30 GMT
...  And why wouldn´t he? in that hypotethical scenario where they would stop being considered reptiles, I refered to both avian and non avian dinos. |
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Post by gwangi on Jan 28, 2012 3:19:37 GMT
Given recent DML postings, I am very suspect about the assumptions you are making regarding Holtz' opinions. Specifically, I am pretty sure he refers to birds as dinosaurs. I thought we were supposed to be done with this?  I don't believe Arioch ever said birds weren't dinosaurs, he is arguing for a re-classification of Dinosauria where they would not be under Reptilia...this goes for birds as well. Reptilia is paraphyletic and worthless anyway unless it is to refer to the animals classically thought of as reptiles. I think we all know this. |
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Post by arioch on Jan 28, 2012 3:34:53 GMT
Not really arguing, again, note that I´m ambivalent on this matter and just cited the opinion of someone way more knowledgeable. I´m done with it unless you want to follow in another thread or via pm, but there´s little more I could say.
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