had they refused to remove his name from the journal, perhaps they could have renamed it “Copeium” instead
2 Likes
You say I’m wrong but then you say that birds are descended from dinosaurs? Are you saying that reptiles are not descended from dinosaurs because…they branched off before dinosaurs?
You have a little bit of a misunderstanding about reptiles and dinosaurs. Yes, birds are directly descended from dinosaurs, in fact they are usually thought of as being dinosaurs. “Reptile” is a higher taxa which contains the living subgroups dinosaurs (only surviving representatives are birds), crocodilians, turtles, tuataras, and squamates (snakes and lizards).
And your language - “older”, “same age” - it sounds like you’re saying they lived at the same time.
They do live at the same time and have since the Jurassic, since again “reptiles” is the higher group containing these subgroups. Crocodilians evolved first in the Triassic, then dinosaurs, then turtles in the Jurassic, then lizards in the Jurassic or Cretaceous (if I remember correctly). Which is what I mean by ‘older’. Reptiles as a group are much older than its subgroup ‘dinosaurs’.
To summarize dinosaurs are not the ancestors of the group we call reptiles. Dinosaurs themselves are reptiles and evolved from preexisting reptiles.
And “evolved” at certain times? I think you mean they branched off - they never stopped (or started) evolving
In this case it is correct to speak of them as ‘evolved’. In this case “Evolved” doesn’t imply they stopped evolving it just means that they perceptibly diverged into a separate major lineage.
Edit: Forgot I was going to include this to help you visualize. This is an (obviously) very simplified version of the reptilian evolutionary tree, along with some relatives. I’m not sure how accurate it is as a whole but the part pertaining to reptiles should be accurate. The branch ‘synapsids’ aren’t considered reptiles according to the strictest interpretation as others have mentioned above, and for some reason fish and amphibians are included; everything else is a reptile. For some reason turtles aren’t included…? (it’s the best I could find super quick on google 
)
7 Likes
Just to add on to this as a tiny correction to hopefully not confuse anyone in the future: “Mammal-like reptiles” is a highly outdated description of synapsids because they were not reptiles, even if morphologically similar. Synapsids have a single temporal fenestra in their skull, while diapsids(essentially equivalent to reptilia) have two, that’s a main feature of what differentiates them, and why mammals are not reptiles.
5 Likes
Thanks for the input!
Well, most of them likely had fur.
1 Like
So lots of room for disagreement of terms. Great to have people tell me I’m wrong and don’t understand what he understands. Must be nice to be right about everything.
Which I think is the best way of understanding the issue. As long as it’s understood that technically birds are reptiles, there’s no reason in application to treat them like reptiles. Hence herpetology being non-avian reptiles and amphibians etc.
The way I see it, birds are the fluffy, flying animals I see often at the birdfeeders, reptiles are the scaly, flightless animals I sometimes find under or on rocks.
4 Likes
Of course there are exceptions.
1 Like
Okay, as I understand the phylogeny that @man4nature posted, “reptiles” didn’t actually exist until the amniotes split into synapsids and diapsids. Is that correct? Because otherwise, it would make no sense to say that mammals/synapsids “didn’t evolve from reptiles.”
This would also mean animals before the split which may have looked like reptiles actually were not; they would just be called amniotes then? A world with only non-tetrapods, amphibians, and amniotes?
Yes I think reptiles as currently understood are diapsids, so calling synapsids reptiles is just contradiction to what the term reptiles means. But honestly I’m not very well versed in the taxonomy at that level, so I’ll let others answer better.
This is the way
1 Like
The branch of the tree between true (eventual) extant amphibians and amniotes those things were called Anthracosaurs (because they were found in layers of anthracite coal), so their name is literally “coal lizards”. However, they’re described as ‘reptile-like amphibians’ and not ‘amphibian-like reptiles’. The fact that their skulls were still anapsid (as seen in Seymouria) is consistent with their more amphibian-like nature (extant amphibians are all still anapsids). So I think it’s safe to say reptiles didn’t really become reptiles (and not amphibians) until the amniotes split into synapsids (mammals) and sauropsids (everything else amniote-wise).
3 Likes
More or less, this is correct, yes. The split between synapsids and diapsids happened very quickly after amniota evolved, however. Amniota as a group evolved from “Stem-amniotes” which more or less resembled reptiles, but were not reptiles as reptiles had not existed yet. Stem-amniotes evolved from amphibian-like ancestors. Mammals are the only currently living Synapsids, but Sauropsids are still going strong, with Lizards, Snakes, Turtles(debatable, turtles might be anapsids- which are a whole other ordeal), Birds, Crocodiles.
2 Likes
Yeah, but that’s because all the fluffy, non-flying, reptiles died out.
Imagine that all mammals except whales and bats died out. It wouldn’t make whales and bats less related, but by removing all the intermediates it becomes harder to see.
11 Likes
Currently, everything with four legs and a few things with fewer than four legs, such as snakes, are considered tetrapods. That’s right, snakes are tetrapods. If all 4-legged things went extinct, snakes would still be considered tetrapods because of their evolutionary history, not because they have legs (though some basal snakes retain vestiges of limbs). Our taxonomic naming system, which us completely for us and not for them, seems odd this way at times, until you realize it’s a way of speaking to the ancestor-descendent relationships over time. Number of legs is not what makes something a tetrapod, but rather shared evolutionary history.
7 Likes
This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.