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Post by tomhet on May 26, 2008 21:32:34 GMT
Actually its not suspected that Diplodocus did not go extinct. Its bulk and a lack of land plant caused it to enter the water. Eventually it started to suck in fish with its vegetation and evolved into Elasmosaurus. Gradually they developed feathers and became smaller And over many millions of years evolved into the penguin Icadyptes salasi about 42MYA. So this shows convergent evolution in that both Ornithischians and Saurichians both developed feathers independently. Triceratops had a beak and birds have a beak. A part of all Dinosaurs are still with us. *LOLs*
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Post by piltdown on May 27, 2008 0:58:18 GMT
And the beaked triceratops went on a weight loss program and lost several tonnes and gained fuzz. The head frill turned into head display feathers, and thus the cockatoo was the descendant of the marginocephalia. Thus Class Aves is actually a paraphyletic taxon. Sorry, couldn't resist that either ;D
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Post by stoneage on May 27, 2008 3:02:54 GMT
What he say?
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Post by piltdown on May 27, 2008 7:40:54 GMT
The cockatoo? He said, "Everybody buy more Papo dinos!" ;D
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Post by richard on May 29, 2008 20:19:18 GMT
Actually its not suspected that Diplodocus did not go extinct. Its bulk and a lack of land plant caused it to enter the water. Eventually it started to suck in fish with its vegetation and evolved into Elasmosaurus. Gradually they developed feathers and became smaller And over many millions of years evolved into the penguin Icadyptes salasi about 42MYA. So this shows convergent evolution in that both Ornithischians and Saurichians both developed feathers independently. Triceratops had a beak and birds have a beak. A part of all Dinosaurs are still with us. lol
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Post by crazycrowman on May 30, 2008 18:04:50 GMT
I for the most lost intrest in continueing to try to provide factual information for feathered dinosaurs.
I keep hearing constantly, (and not just here) about the "chinese fraud" stuff, (DESPITE ARCHEOPTEYX, THANK YOU VERY MUCH) and so much more of this sounds way too much to me like the "Devil put it there" or "its gods way" you hear when attempting to talk sense to a creationist.
I always take that moment to insert a qup my grandfather used to use....
"Never try to talk sense to a pig, as you will only annoy yourself and confuse the pig"
Learn a little about birds please. Birds are manoraptrian dinosaurs, and it really is that simple. As much as humans are great apes, which is also, that simple.
To this day "Reptiles" remain a "sloppy" and badly allighned and "lumpy" taxonmic group, to begin with. If it pleases people to think of dinosaurs are reptiles, please lump birds in there as reptiles also, as there is simply no way to separate them from dinosaurs based on the scientific and fossil evidence...
Even cockatoos.
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Post by thagomizer on May 31, 2008 0:40:21 GMT
To this day "Reptiles" remain a "sloppy" and badly allighned and "lumpy" taxonmic group, to begin with. If it pleases people to think of dinosaurs are reptiles, please lump birds in there as reptiles also, as there is simply no way to separate them from dinosaurs based on the scientific and fossil evidence... This is a good point. If you're going to insist on separating reptiles and birds as if there's a difference, many "dinosaurs" would go into the bird category, based on what we know today. If Linnean classification were still in full force, oviraptorids, dromaeosaurids, troodontids, etc. would all be solidly in Class Aves. The only reason they're not is that we've re-defined and re-re-defined what "Aves" is several times over the last 20 years, and it no longer has anything to do with being bird-like or not. If somehow a cladogram showed ostriches arose from one lineage of prehistoric birds instead of the one we now think they did, they wouldn't be birds anymore than Deinonychus is. Does that mean ostriches would be "reptiles" and we should start portraying them with scales?
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Post by sbell on May 31, 2008 4:06:49 GMT
To this day "Reptiles" remain a "sloppy" and badly allighned and "lumpy" taxonmic group, to begin with. If it pleases people to think of dinosaurs are reptiles, please lump birds in there as reptiles also, as there is simply no way to separate them from dinosaurs based on the scientific and fossil evidence... Even cockatoos. This is true of so many words that we use to describe animals. The most egregious, of course, is 'bugs'. However, most of our Linnean groups don't really hold up either--'amphibian' is a great general term for modern lissamphibians, but it falls apart a bit when we consider all of the fossil forms that get lumped with it, because what defines an amphibian? It is all members of that group, plus their descendants. Which means all frogs, newts, caecilians, lepospondylls, temnospondylls, reptilomorphs, anapsids, diapsids, and synapsids (the last three all descended from one of those, but plese don't ask me which. I can't remember, and it's easy enough to look up, since I'm assuming you have access to a computer). And this goes further: What is a fish? Traditionally, it is a primarily aquatic vertebrate that probably has fins. As a taxonomic category (good ol' Pisces) it is completely meaningless. Modern agnathans are very separate from sharks and bony fish (and possibly from other agnathans); and those latter two are further very separate from each other (I can't even remember how the divergences of those groups go). As well, even if we restrict the term 'fish' only to the Osteichthyans, what does that mean? It means all actinopterygians and sarcopterygians and their descendants, which makes a fun trip back to the previous paragraph about amphibians (which descended from sarcopterygians like eusthenopteron, panderichthys and tiktaalik). What does it all mean? That most of our common terms are best thought of as morphotypes for the animals we see frequently--bird=feathered winged thing; mammal=usually hairy, lactating thing; reptile=usually scaly thing; amphibian=thing with a tadpole stage; fish=swimming finned thing. In other words, most of these (mammals excluded) are not great taxonomic labels. "Bird" comes close as a name for a clade within the actual reptiles. I've read it written ("heard it said" sounds better, but it would be untrue) that taxonomy would be much easier if we could get past the word reptile, since it is functionally meaningless as well (where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?). And now I get off my cladistic-laden soap box. And I'm not sure, but I wanted to make certain that my tone was not meant to be sarcastic; I wholeheartedly agree with crazycrowman (who I suspect may not be crazy).
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Post by Dinotoyforum on May 31, 2008 8:32:45 GMT
To this day "Reptiles" remain a "sloppy" and badly allighned and "lumpy" taxonmic group, to begin with. If it pleases people to think of dinosaurs are reptiles, please lump birds in there as reptiles also, as there is simply no way to separate them from dinosaurs based on the scientific and fossil evidence... Even cockatoos. This is true of so many words that we use to describe animals. The most egregious, of course, is 'bugs'. However, most of our Linnean groups don't really hold up either--'amphibian' is a great general term for modern lissamphibians, but it falls apart a bit when we consider all of the fossil forms that get lumped with it, because what defines an amphibian? It is all members of that group, plus their descendants. Which means all frogs, newts, caecilians, lepospondylls, temnospondylls, reptilomorphs, anapsids, diapsids, and synapsids (the last three all descended from one of those, but plese don't ask me which. I can't remember, and it's easy enough to look up, since I'm assuming you have access to a computer). And this goes further: What is a fish? Traditionally, it is a primarily aquatic vertebrate that probably has fins. As a taxonomic category (good ol' Pisces) it is completely meaningless. Modern agnathans are very separate from sharks and bony fish (and possibly from other agnathans); and those latter two are further very separate from each other (I can't even remember how the divergences of those groups go). As well, even if we restrict the term 'fish' only to the Osteichthyans, what does that mean? It means all actinopterygians and sarcopterygians and their descendants, which makes a fun trip back to the previous paragraph about amphibians (which descended from sarcopterygians like eusthenopteron, panderichthys and tiktaalik). What does it all mean? That most of our common terms are best thought of as morphotypes for the animals we see frequently--bird=feathered winged thing; mammal=usually hairy, lactating thing; reptile=usually scaly thing; amphibian=thing with a tadpole stage; fish=swimming finned thing. In other words, most of these (mammals excluded) are not great taxonomic labels. "Bird" comes close as a name for a clade within the actual reptiles. I've read it written ("heard it said" sounds better, but it would be untrue) that taxonomy would be much easier if we could get past the word reptile, since it is functionally meaningless as well (where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?). And now I get off my cladistic-laden soap box. And I'm not sure, but I wanted to make certain that my tone was not meant to be sarcastic; I wholeheartedly agree with crazycrowman (who I suspect may not be crazy). Yes, the problem of dividing a continuum into discrete units.
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Post by sbell on May 31, 2008 13:40:21 GMT
This is true of so many words that we use to describe animals. The most egregious, of course, is 'bugs'. However, most of our Linnean groups don't really hold up either--'amphibian' is a great general term for modern lissamphibians, but it falls apart a bit when we consider all of the fossil forms that get lumped with it, because what defines an amphibian? It is all members of that group, plus their descendants. Which means all frogs, newts, caecilians, lepospondylls, temnospondylls, reptilomorphs, anapsids, diapsids, and synapsids (the last three all descended from one of those, but plese don't ask me which. I can't remember, and it's easy enough to look up, since I'm assuming you have access to a computer). And this goes further: What is a fish? Traditionally, it is a primarily aquatic vertebrate that probably has fins. As a taxonomic category (good ol' Pisces) it is completely meaningless. Modern agnathans are very separate from sharks and bony fish (and possibly from other agnathans); and those latter two are further very separate from each other (I can't even remember how the divergences of those groups go). As well, even if we restrict the term 'fish' only to the Osteichthyans, what does that mean? It means all actinopterygians and sarcopterygians and their descendants, which makes a fun trip back to the previous paragraph about amphibians (which descended from sarcopterygians like eusthenopteron, panderichthys and tiktaalik). What does it all mean? That most of our common terms are best thought of as morphotypes for the animals we see frequently--bird=feathered winged thing; mammal=usually hairy, lactating thing; reptile=usually scaly thing; amphibian=thing with a tadpole stage; fish=swimming finned thing. In other words, most of these (mammals excluded) are not great taxonomic labels. "Bird" comes close as a name for a clade within the actual reptiles. I've read it written ("heard it said" sounds better, but it would be untrue) that taxonomy would be much easier if we could get past the word reptile, since it is functionally meaningless as well (where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?). And now I get off my cladistic-laden soap box. And I'm not sure, but I wanted to make certain that my tone was not meant to be sarcastic; I wholeheartedly agree with crazycrowman (who I suspect may not be crazy). Yes, the problem of dividing a continuum into discrete units. Your version is much more succinct.
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Post by crazycrowman on Jun 1, 2008 3:31:14 GMT
"(where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?)"
That is where no one can agree....I know some who lump living aves firmly within diapsids, and I agree with that lumping.
I try to express to people, at least with "reptiles", there is simply so much time and divergent evolution between groups, (this goes for "fish" and inverts also) that it can be very confusing to try to ally the things that remain. Modern Crocodiles and Modern Alligators have less in common genetically with each other then we do with a Baboon. Crocodilans as a whole are closer in relation to modern birds the anything else living that is "reptile", and with birds are the only living archosaurs.
Turtles, with thier anapsid-ish (totally depending on who you speak to on reversion/vs/living diapsid here) skulls, and they are frustratingly distinct in so many ways. Snakes and lizards are a much easier lumping, as long as you can remember not to toss in the Tuataras, the only living sphenodontids!
And then you have to stick in pterosaurs, and mosasaurs, and..on, and on, and on...It really is a mess....*darn our human need to understand and attempt to classify things with crazy systems we invent!*
"(who I suspect may not be crazy)."
Varies from day to day ;D
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Post by sbell on Jun 1, 2008 4:02:26 GMT
"(where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?)" That is where no one can agree....I know some who lump living aves firmly within diapsids, and I agree with that lumping. I try to express to people, at least with "reptiles", there is simply so much time and divergent evolution between groups, (this goes for "fish" and inverts also) that it can be very confusing to try to ally the things that remain. Modern Crocodiles and Modern Alligators have less in common genetically with each other then we do with a Baboon. Crocodilans as a whole are closer in relation to modern birds the anything else living that is "reptile", and with birds are the only living archosaurs. Turtles, with thier anapsid-ish (totally depending on who you speak to on reversion/vs/living diapsid here) skulls, and they are frustratingly distinct in so many ways. Snakes and lizards are a much easier lumping, as long as you can remember not to toss in the Tuataras, the only living sphenodontids! And then you have to stick in pterosaurs, and mosasaurs, and..on, and on, and on...It really is a mess....*darn our human need to understand and attempt to classify things with crazy systems we invent!* "(who I suspect may not be crazy)." Varies from day to day ;D Mosasaurs are relatively easy--they are squamates (but you might start a fight if you ask whether they are nested with monitor lizards or snakes). And nothing bugs me more than the popular notion of tuataras as living dinosaurs. My son got a book from New Zealand that refers to them exactly like that--that they are the last of the dinosaurs. Ironically, it is speaking to a bird at the time! But I remember seeing this depiction way back as a kid as well. The problem is that tuataras are still lepidosaur diapsids, so there is no way they can be 'dinosaur' in even the loosest of definitions. And 'invertebrate' may be the worst paraphyletic term of all time--since it includes everything fro sponges to corals, arthropods, molluscs and echinoderms & graptolites , which are somehow eventually related to chordates. It turns out to all be arbitrary, like absolutely every living thing is connected in some (DNA) way.
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tiermann
Full Member
Playmosaurus
Posts: 142
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Post by tiermann on Jun 18, 2008 19:00:33 GMT
It turns out to all be arbitrary, like absolutely every living thing is connected in some (DNA) way. That's it in a nutshell I think. If I have 2 boxes and the measurements of one are 2x2x2 and the other is 2x2x4 which is descended from which? There is no way to tell definitevely because boxes don't have DNA. Evolution is genetic so using morphology to describe evolution is at best an approximation.
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Post by Dinotoyforum on Jul 20, 2008 1:04:21 GMT
Imported from another thread... Oh really? Define "bird". What characteristics make Archaeopteryx a bird and not Microraptor? Thread seems to be derailing again... Please feel free to create a new thread to discuss this, or go to an existing feathered dinosaurs thread.
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Post by stoneage on Jul 20, 2008 1:49:07 GMT
Better yet why is Archaeopteryx a bird. No bill, teeth on premaxilla & maxilla bones, flat sternum (breast bone), long bony tail(gastralia, belly ribs), 3 clawed unfused fingers,nasal openings far forward, neck attached to skull from the rear, wrist hand joints flexible,solid bones except for cervical & anterior vertebrae, tridactyl hand digits 1-2-3 as opposed to birds digits 2-3-4, etc.
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Post by richard on Jul 20, 2008 3:39:58 GMT
Crocodiles are very close to birds; in fact they are closer than what they are to any other reptile but crocodiles are still reptiles... so no matter how much dinosaurs and birds share dinosaurs are dinosaurs and birds are birds, they may have feathers and some caracteristics of birds but that don't make them birds
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Post by sid on Jul 20, 2008 7:57:56 GMT
Crocodiles are very close to birds; in fact they are closer than what they are to any other reptile but crocodiles are still reptiles... so no matter how much dinosaurs and birds share dinosaurs are dinosaurs and birds are birds, they may have feathers and some caracteristics of birds but that don't make them birds That's right...And then there's to consider one thing:birds FLY,something that no dinosaurs did;and that's enough for me to consider them a separate group than to dinosaurs;evolved from them,sure,but still different
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Post by Dinotoyforum on Jul 20, 2008 9:59:32 GMT
We seem to going over old ground here - so to pluck out from this very thread, a response:
"This is true of so many words that we use to describe animals. The most egregious, of course, is 'bugs'.
However, most of our Linnean groups don't really hold up either--'amphibian' is a great general term for modern lissamphibians, but it falls apart a bit when we consider all of the fossil forms that get lumped with it, because what defines an amphibian? It is all members of that group, plus their descendants. Which means all frogs, newts, caecilians, lepospondylls, temnospondylls, reptilomorphs, anapsids, diapsids, and synapsids (the last three all descended from one of those, but plese don't ask me which. I can't remember, and it's easy enough to look up, since I'm assuming you have access to a computer).
And this goes further: What is a fish? Traditionally, it is a primarily aquatic vertebrate that probably has fins. As a taxonomic category (good ol' Pisces) it is completely meaningless. Modern agnathans are very separate from sharks and bony fish (and possibly from other agnathans); and those latter two are further very separate from each other (I can't even remember how the divergences of those groups go). As well, even if we restrict the term 'fish' only to the Osteichthyans, what does that mean? It means all actinopterygians and sarcopterygians and their descendants, which makes a fun trip back to the previous paragraph about amphibians (which descended from sarcopterygians like eusthenopteron, panderichthys and tiktaalik).
What does it all mean? That most of our common terms are best thought of as morphotypes for the animals we see frequently--bird=feathered winged thing; mammal=usually hairy, lactating thing; reptile=usually scaly thing; amphibian=thing with a tadpole stage; fish=swimming finned thing. In other words, most of these (mammals excluded) are not great taxonomic labels. "Bird" comes close as a name for a clade within the actual reptiles.
I've read it written ("heard it said" sounds better, but it would be untrue) that taxonomy would be much easier if we could get past the word reptile, since it is functionally meaningless as well (where do we stop? At the split of the synapsids from the diapsids/anapsids? Or before that, into the reptilomorphs?).
And now I get off my cladistic-laden soap box. And I'm not sure, but I wanted to make certain that my tone was not meant to be sarcastic; I wholeheartedly agree with crazycrowman (who I suspect may not be crazy)."
"Yes, the problem of dividing a continuum into discrete units. "
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Post by Dinotoyforum on Jul 20, 2008 10:04:00 GMT
Crocodiles are very close to birds; in fact they are closer than what they are to any other reptile but crocodiles are still reptiles... so no matter how much dinosaurs and birds share dinosaurs are dinosaurs and birds are birds, they may have feathers and some caracteristics of birds but that don't make them birds That's right...And then there's to consider one thing:birds FLY,something that no dinosaurs did;and that's enough for me to consider them a separate group than to dinosaurs;evolved from them,sure,but still different Taxonomy is based on anatomical features. And not all derived dinosaurs fly. So
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Post by Dinotoyforum on Jul 20, 2008 10:21:08 GMT
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