rock
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Post by rock on May 30, 2019 3:37:25 GMT 5
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Post by Infinity Blade on May 30, 2019 7:24:23 GMT 5
I really hope I don't need to address whether or not they're literal dinosaurs. As for whether or not they're close relatives,  I guess you could say they're "close" in the sense that, aside from actual living dinosaurs (read: birds), they're the closest living relatives to ancient dinosaurs (and by extension, the birds surviving today) and sharing a common ancestor with them. But I wonder if it would be appropriate to call their respective clades "closely related". That may depend on how you'd answer this parallel question: "Are synapsids and sauropsids "closely related" just for sharing a common ancestor?". It would be less appropriate to deem dinosaurs proper as being related to crocodiles proper and alligators proper. At least going from a quick gander at Wikipedia's articles, dinosaurs proper first appeared like, well over 10 million years after the avemetatarsalian-pseudosuchian split (when the last common ancestor between bird-line and croc-line archosaurs diverged). On the other hand, crocodiles proper and alligators proper first appeared during the early Eocene and late Eocene, respectively, which is WAAAAAAAAAAYYYY after that split. |
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Post by dinosauria101 on May 30, 2019 9:20:05 GMT 5
As Infinity Blade said, the closest is that they're both archosaurs. Other than that, nothing much
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Post by creature386 on May 30, 2019 14:44:47 GMT 5
Rock, just asking, do you know what cladograms are, where to find them and how to read them? You seem to be interested in taxonomy and many questions you have are settled issues among scientists, so you could answer your questions by yourself if you know how to read them (plus, I like explaining stuff).
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rock
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Post by rock on May 30, 2019 15:12:42 GMT 5
Rock, just asking, do you know what cladograms are, where to find them and how to read them? You seem to be interested in taxonomy and many questions you have are settled issues among scientists, so you could answer your questions by yourself if you know how to read them (plus, I like explaining stuff). i am just a bit curious because i heard they were not related on yahoo , just wanted to see if that was true or not |
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Post by creature386 on May 30, 2019 16:04:38 GMT 5
Everything is related to something in some way.
That's why we prefer quantitative statements for which we have cladograms.
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Post by sam1 on May 30, 2019 17:03:56 GMT 5
I'd even say that they are more closely related to amphibians than to dinosaurs which were warm blooded with perhaps even more diversification potential than mammals of today. As everyone should know, birds are basically dinosaurs
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rock
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Post by rock on May 30, 2019 17:05:52 GMT 5
I'd even say that they are more closely related to amphibians than to dinosaurs which were warm blooded with perhaps even more diversification potential than mammals of today. As everyone should know, birds are basically dinosaurs no alligators and crocodiles are reptiles like dinosaurs so alligators and crocodiles are much more closley related to dinosaurs than to amphibians. |
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Post by creature386 on May 30, 2019 17:58:11 GMT 5
I'd even say that they are more closely related to amphibians than to dinosaurs which were warm blooded with perhaps even more diversification potential than mammals of today. As everyone should know, birds are basically dinosaurs Well, crocodiles have a four-chambered heart, so they likely had warm-blooded ancestors. |
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Post by theropod on May 30, 2019 18:21:28 GMT 5
sam1: Birds are not "basically dinosaurs", they are dinosaurs. Crocodiles are not dinosaurs. However, they are far more closely related to dinosaurs than to lissamphibians, which are no more closely related to crocodiles than to humans. Also "warm-bloodedness" has little to do with "diversification potential". Insects are not "warm blooded". rock: The person you heard that from was likely a creationist. All life on earth is related, and the only ones to deny this are those who deny evolution itself. Crocodiles are the closest living relatives of dinosaurs, but that doesn’t make them dinosaurs, even though this is sometimes claimed by people who try to make them more sensational (as if that were necessary).
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Post by sam1 on May 30, 2019 18:43:18 GMT 5
sam1 : Birds are not "basically dinosaurs", they are dinosaurs. Crocodiles are not dinosaurs. However, they are far more closely related to dinosaurs than to lissamphibians, which are no more closely related to crocodiles than to humans. Also "warm-bloodedness" has little to do with "diversification potential". Insects are not "warm blooded". rock : The person you heard that from was likely a creationist. All life on earth is related, and the only ones to deny this are those who deny evolution itself. Crocodiles are the closest living relatives of dinosaurs, but that doesn’t make them dinosaurs, even though this is sometimes claimed by people who try to make them more sensational (as if that were necessary). What I meant by diversification potential, is the range of sizes, shapes and lifestyles, not the number of species. In that regard insects are far more limited than warm blooded animals. |
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Post by theropod on May 30, 2019 19:04:58 GMT 5
In terms of shapes and lifestyles, not really. There are ectothermic animals pretty much everywhere there are endotherms.
In terms of size, what limits insects is their respiratory system, not their thermoregulation. There might be some restrictions on the maximum size of ectothermic animals (which have nothing to do with the limits on the maximum size of arthropods, which are far more limited, yet are still far more diverse than all other animals combined), but the same could be said for the minimum size of endothermic animals. Something like a shrew or hummingbird seems to be close to the limits of what they can achieve, homeotherms the size of ants or mites are impossible simply due to heat loss.
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Post by sam1 on May 31, 2019 1:00:04 GMT 5
Good points, but you missed(understandably, as it was not an obvious one) the context of me bringing up the endothermy here.
It is the main detail setting apart dinosaurs and non-avian reptiles.
And it makes a huge differentiating effect, in some non-taxonomic aspects greater than any genetical difference between reptiles and amphibians.
It is the single factor that allowed dinosaurs to thrive on the land for 60 million years in most spectacular and diverse fashion ; to grow from hummingbird to giant sauropods, to survive on Antarctica( the Emperor Penguin) and traverse the planet from pole to pole(the Arctic tern) each year, etc etc.
Reptiles and amphibians otoh, ultimately are limited to relatively similar niches and ranges(with comparatively great advantage to reptiles, of course, but that's why I used the word relative).
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rock
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Post by rock on May 31, 2019 1:38:06 GMT 5
Good points, but you missed(understandably, as it was not an obvious one) the context of me bringing up the endothermy here. It is the main detail setting apart dinosaurs and non-avian reptiles. And it makes a huge differentiating effect, in some non-taxonomic aspects greater than any genetical difference between reptiles and amphibians. It is the single factor that allowed dinosaurs to thrive on the land for 60 million years in most spectacular and diverse fashion ; to grow from hummingbird to giant sauropods, to survive on Antarctica( the Emperor Penguin) and traverse the planet from pole to pole(the Arctic tern) each year, etc etc. Reptiles and amphibians otoh, ultimately are limited to relatively similar niches and ranges(with comparatively great advantage to reptiles, of course, but that's why I used the word relative). well reptiles share much more in comman with amphibans they are equally related to amphibans as they are with mammals which is not very close but still closer than to fish but still pretty distant |
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Post by dinosauria101 on May 31, 2019 1:42:07 GMT 5
^Equally? How do you know that?
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