Are birds really reptiles?

https://www.livescience.com/animals/birds/are-birds-reptiles

What do you think? Are we getting closer to accepting the genetic evidence as grounds for reclassification?

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I think most if not all herpetologists and ornithologists accept the current understanding of the interrelatedness of the organisms they study. Thereā€™s still debate as to how to deal with the modern groups taxonomically and I recall seeing various arrangements (e.g., elevating current reptile orders to classes). But it probably wonā€™t change the focus of herp and bird researchers, regardless. I donā€™t see ornithologists suddenly including crocodilians among their study animals. And even if Reptilia is paraphyletic as currently used, it is a functional group for research purposes.

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I donā€™t really know much about macro evolution and when one group can be considered to have become another and all that, but I donā€™t think anyone argues that dinosaurs arenā€™t reptiles, and birds are theropods. Also, birds/dinosaurs are archosaurs, a group which includes crocodiles, like jnstuart mentioned.

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Of course we all know that ā€œbirds are reptilesā€ but thereā€™s some fudge involved. There was a common ancestor of both (dinosaurs) and now we have 2 groups of descendants that are closely related. Doesnā€™t that show up on the family tree? Ie both are in the same Kingdom, Phylum, Classā€¦up to somewhere were they diverge.

Well said, James. A lot of new iNatters submit pictures of ā€œtreesā€. Even ā€œmangroveā€ is polyphyletic.

Even if we could taxonomically reclassify a tree, its role in our lives would not change.

A tree is still a tree to the bird nesting in its branches, to the artist inspired by its beauty, and to the lovers lying in its shade.

Some things are defined, not by their classification, but by their meaning in our lives.

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Wdym by that? It sounds as if youā€™re saying that dinosaurs are the common ancestor of reptiles and birds, which isnā€™t the case. Birds are technically theropod dinosaurs, or descended from them depending on how you look at it. Crocodiles and tuataras are older than dinosaurs, turtles are roughly the same age, and lizards evolved not much later (snakes evolved from lizards in the Cretaceous I believe).

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Certainly birds are dinosaurs. Whether birds are reptiles depends on how you define reptiles. No matter ā€“ weā€™re all fish anyway.

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ā€¦fish-derivatives.

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Are birds reptiles? There are arguments for both, so it does come down to what @sedgequeen has said:

Option 1: Birds are reptiles, making ā€œReptiliaā€ a monophyletic taxon, and all is well
Option 2: Birds are not reptiles, because ā€œreptilesā€ as a group do not exist in terms of phylogeny

Personally, I prefer the second approach. Earlier ancestors of mammals (which are also not considered ā€œreptilesā€ s. str.) still looked very reptilian. IMO that shows that not everything that looks reptilian can and needs to be put into the same class. (Unless we also want to put mammals into reptiles. But that would just be the group we currently call ā€œAmniotaā€ = all tetrapods except for amphibians)
Splitting reptiles may have some practical disadvantages though and certainly would make Amniote taxonomy more messy.

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I get what youā€™re saying and thatā€™s probably the view I would take, but mammals have also diverged far more in their anatomy (especially reproductive) than birds from reptiles. Obviously birds have changed drastically to fly, but I would kinda think of that as a more environmental adaptation than a clade-defining trait (obviously since it can evolve independently). But like I mentioned earlier, I really donā€™t know much about evolution at this level anyway. Really makes you realize how necessary and yet arbitrary taxonomy is at the macro evolutionary level lol

I think birds have enough autapomorphies (warm-bloodedness, evolution of feathers, lung with anterior and posterior air sack, carpometacarpus, reduction from 5 fingers to 3 on the front-extremities, etc.) to warrant their stem line being treated ā€œthe sameā€ as the mammalian one.

We could also neatly avoid the issue by referring to the group ā€œreptilesā€+birds by their actual name ā€œSauropsidaā€.
Though, personally, I wouldnā€™t mind a splitting of ā€œReptiliaā€ (excl. birds) into three big classes turtles, crocodiles, and squamates. (Or class Sauropsida with those three and birds/dinosaurs as subclasses)
Iā€™ll admit that Iā€™m more familiar with inverts than with vertebrates though, so I donā€™t know whether thatā€™s actually feasible.

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Your organization would leave out Order Rhynochochalia (tuataras). Lepidosauria is their common taxonomic name containing that order and O. Squamata. However, when I think about the mission of iNaturalist (to better connect people to nature), I worry that getting rid of Reptilia would be counter to that. The average person doesnā€™t understand that ā€˜reptilesā€™ arenā€™t a thing, or that ā€˜lizardsā€™ are not monophyletic taxon. Those iconic names help people in that they allow people to start with a coarse identification so that a more precise ID can be made. Personally, I think ā€˜reptilesā€™ and birds are fine as is, just as ā€˜lizardsā€™ are fine as is since those iconic names help start the identification process. One sometimes sees the clunky phrase non-avian reptiles in papers, but as far as I know, none of the professional societies is working to change their scope to include birds or to change their their name to something like the Society for the Study of Amphibians and Non-avian Reptiles. Itā€™s just understood that names are more a convenience and part of convention than a representation of actual evolutionary relationships.

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Birds might or might not be included in reptiles but they arenā€™t herpetofauna. I always liked that term for amphibians and non-avian reptiles. What do herpers and herpetologists chase? Herpetofauna.

Avifauna, however, is just a snooty way to say birds.

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Crocodiles and birds are both archosaurs, while turtles and squamates arenā€™t.

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For iNat purposes I agree. I would not be opposed to having other non-monophyletic iconic taxa such as ā€œtreesā€ or including other fish in ā€œfishā€ in addition to Actinopterygii.
On a broader scientific level, I donā€™t think getting rid of ā€œReptiliaā€ in favour of the others would matter much however. I donā€™t know whether herpetologists tend to specialise in everything herpetofauna or whether they usually become an expert for a smaller group. In any case, the three new groups (Testudines, Crocodilia, Lepidosauria (thank you for correcting my taxonomy, btw! :D)) wouldnā€™t be that difficult to explain to non-herpers, I think, because they are quite different.

Itā€™s not the non-herpers Iā€™m worried about, itā€™s the non-biologists, the non-educated. Thatā€™s who this site should be geared toward.

Those, like me, who photograph what they see.
We donā€™t have the need to tangle ourselves in the words the others use. They will still understand when we say we photographed a bird, reptile, lizard, treeā€¦
Thank you

No.
This is sort of like saying that since humans (and all other forms of life) evolved from LUCA (Last Universal Common Ancestor), we are LUCA.

As people mentioned I think itā€™s more complicated than that. The difficulty with taxonomy is that while there are standards for what physically and spatially constitutes a lineage or clade or whatever, there are no standards for a groupā€™s temporal relationships. This issue might be similar to the evolutionary species concept, where a lineage maintains its identity over time and space, and is on a completely separated evolutionary trajectory than its relatives, and thus can be treated as a distinct taxa. This is clearly the case with birds and reptiles on a much larger scale, so could they be said to be a class distinct from reptiles? But then the same could be said for every subcategory of each group. Since every distinct lineage on any taxonomic level could be argued to be treated separately from its related lineages based on the LUCA argument, thatā€™s not really a good argument for whether birds are not or are reptiles. Itā€™s a good argument to prove that they are on a distinct evolutionary trajectory- they are a unique lineage- but no one is arguing that. Their relationship with or within the group reptiles is less clear. As others have pointed out, crocodilians closest relatives are birds, not other reptiles. So ultimately the LUCA argument comes down to your understanding of groups in time, like when does a group stop being one and become another.
Based on my very very limited understanding of taxonomy at this level, I think a good solution would be to have Reptilia (class)=> Archosauria (subclass)=> Crocodilia (superorder), Dinosauria (superorder)=> Theropoda (birds- order). But I realize that this might be less feasible and more complicated than that, and Iā€™m not sure if those specific rankings would make sense scientifically.
And as others have pointed out, there is no reason why this needs to be implemented by iNat, since it would just create confusion.

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I find these descriptions amusing as being technically phylogenetically correct. But I think theyā€™re unhelpful and irrelevant in most contexts. I think itā€™s accurate to say that dinosaurs are extinct, because birds arenā€™t really dinosaurs just like whales are clearly no longer hoofed mammals.

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