Talk:Bird

The page's infobox lists Aves as a distinct class, but Wikispecies lists it as a subclass of Reptilia. 146.7.15.26 (talk) 16:46, 15 July 2025 (UTC)

Reopening this because there no longer seems to be agreement on what the consensus is. This has been discussed extensively on this page in the past. The discussion revolves around some related questions:

• Should the connection between birds and dinosaurs be mentioned in the lead sentence/paragraph of the article?
• Should the lead of the article refer to birds *as* dinosaurs, versus saying something like they evolved from or are descended from dinosaurs?
• Should the lead say or imply that usage of the word “dinosaur” to exclude birds is wrong?
• Should the lead explain what is meant by saying that birds are dinosaurs?

All of the above also applies to referring to birds as reptiles, although nobody seems to be suggesting that the lead sentence should call birds reptiles, not sure why.

I think the following things are uncontroversial:

• The ancestors of modern birds are Mesozoic theropod dinosaurs.
• Scientists generally use “dinosaur” as a synonym of the taxonomic group Dinosauria and would thus say that birds are dinosaurs.
• The popular conception of dinosaurs does not include birds.

Things I would argue:

• "The ancestors of modern birds are Mesozoic theropod dinosaurs." is the important information that we want the reader of this lead section to come away with.
• The casual reader does not need to know how scientists use the word “dinosaur” on a page about birds.
• It is not Wikipedia’s job to police how people use the English language, and we shouldn’t imply that other usages of the word dinosaur are incorrect.
• If the lead is going to refer to birds as dinosaurs, it needs to explain why
• A focus on this usage of “dinosaur” is unnecessary in the lead
• It’s perfectly acceptable for the appropriate section of the article itself to call birds dinosaurs, explain why, and then continue with that usage.

My proposal:

• The lead sentence refers to birds as vertebrates, with no reference to dinosaurs or reptiles in the lead paragraph
• The language in the second paragraph that talks about evolution is something like:

“Birds are descended from Mesozoic theropod dinosaurs and are the only living representatives of that group. Their closest living relatives are the crocodilians.” Somatochlora (talk) 13:33, 17 March 2026 (UTC)

No need for further clarification as the present lead sentence, "Birds are a group of warm-blooded theropod dinosaurs constituting the class Aves" has been the lead since late October 2025 and hopefully read by all of the main editors here. The language is accurate, brief, and encyclopedic. Randy Kryn (talk) 13:46, 17 March 2026 (UTC)

The most important classification of birds is that they are vertebrate animals, placing them in context with other things that exist in the world. The pages for mammal, fish, reptile, and amphibian all use "vertebrate animal" in the lead sentence. Instead this page refers to them by reference to two groups of which birds are the only extant members. The idea that this page about a diverse, familiar, economically and culturally important group of animals should immediately start with a reference to what extinct taxa they are related to seems absurd. Somatochlora (talk) 14:16, 18 March 2026 (UTC)

Please add 'vertebrate animal' in the lead listing, thanks Somatochlora. Room for both descriptors in the opening sentences, but the uniqueness among living animals of the dinosaur descriptor shows the importance of continuing that classification at first mention. Randy Kryn (talk) 14:48, 19 March 2026 (UTC)

I just do not understand why listing a specific taxonomic group that birds are the only living members of could be considered important enough to mention before even talking about the basic characteristics and diversity of extant birds. Yeah, it's cool that birds are dinosaurs, and there is lots of pseudoscience out there trying to deny the link, both of which are why, I assume, people feel strongly about this, but I think objectively it is just not one of the key facts that needs to be mentioned in the first sentence of the article laying out what we are even talking about when we say "bird". We could also mention that birds are eukaryotes, chordates, archosaurs, or avemetatarsalians in the lead sentence but we need to make some choices about what is most important. Somatochlora (talk) 15:29, 19 March 2026 (UTC)

"Dinosaur" covers those terms and is much more understandable to the reader. The importance of the first sentence mention covers many aspects of animal life without explaining in-depth - that dinosaurs survived when people have been told their whole lives that no, they are extinct. That dinosaurs only extant branch are everywhere. That the success of the dinosaur, now represented by over 11,000 species, ranks with the most important animal legacies. And so on. Keeping the fact up-front, and adding the 'vertebrate' descriptor, would cover all bases (to spout an accurate sports term). Randy Kryn (talk) 15:46, 19 March 2026 (UTC)

This page is about birds though, not dinosaurs. It is very important for the article about dinosaurs to stress that dinosaurs still exist in a sense. It is less important for this article, which is why it should be left to the second paragraph like it was for several years. The lead sentence should clearly and concisely lay out what the topic of the article is. "Vertebrate animal" is perfect in describing how birds are related to other extant animals. Adding "dinosaur" does not clarify, it is at worst confusing and at best merely communicates how birds are related to certain extinct animals. I do not understand how expressing how an extant taxon is related to extinct animals can possibly seen as an important thing to communicate in the very first sentence of the article. Somatochlora (talk) 17:22, 19 March 2026 (UTC)

But dinosaur just means a member of Dinosauria which birds are. As time progresses, books and stuff include the fact that birds are dinosaurs. Popular conceptions would make things like Dimetrodon a "reptile" which it isn't, it's a synapsid or a stem-mammal. It can NOT be a reptile because reptiles=sauropsids. ~2026-17247-67 (talk) 14:37, 19 March 2026 (UTC)

No, "dinosaur" and "reptile" are English words that do not always mean what you are suggesting. I use "reptile" all the time professionally to mean turtles, lizards, and snakes, a useful category of wildlife to take about. I would be laughed out of the room if I suggested we needed to start including birds in that category. Somatochlora (talk) 14:59, 19 March 2026 (UTC)

For birds I think it makes sense to point out that they are dinosaurs, even though it's nerdy. It best characterizes them in the tree of life, for example in relation to mammals.

It's not the same as saying humans are a type of tetrapod fish, a characteristic they share with all mammals and indeed also with birds. This does not set them apart. By contrast, Birds as surviving dinosaurs sets them apart.

Aecur (talk) 12:28, 24 March 2026 (UTC)

The issue isn't whether to state prominently that birds are dinosaurs (using scientific definitions), it's whether it is the most important feature of birds and gets stated in the opening sentence. The second paragraph covers the evolution of birds from within dinosaurs (English language terms) in enough detail that people can understand the context. Stating it bluntly in the first sentence is more likely to confuse and is not appropriate for a general article on birds (second paragraph is still prominent), whereas it would be for a more specialised article on evolution of birds

The opening sentence needs to inform people about what a bird is. Does telling them that birds are dinosaurs tell them anything useful? What characteristis of dinosaurs is informative about the nature of birds? It would be far more informative to mention that they are chordates or vertebrates or amniotes, which tell you something important about their biology. I would personally favour "amniotic vertebrates" in place of "theropod dinosaurs" in the opening sentences and leave the dinosaur affinity until the second paragraph.  —  Jts1882 | talk  13:16, 24 March 2026 (UTC)

I agree with this.

The first sentence should not state that birds are dinosaurs. It's misleading for all of the reasons already stated by others. TravelinGcauldroN (talk) 14:55, 24 March 2026 (UTC)

And thank you for your only edit on Wikipedia. Since this is your first edit I'd request that you actually explain, in your own words, how stating a clear long-term fact is "misleading". Thanks. Randy Kryn (talk) 14:57, 24 March 2026 (UTC)

Reptile is a paraphyletic term which can be helpful to use. Reptile = non-bird sauropsid. Simple as that. Just like how fishis a paraphyletic term that refers to non-tetrapod vertebrates

If you want to remove it from the lede, the alternative explanation below needs to explain how you can NOT evolve out of a clade and that therefore birds=dinosaurs. The more we learn about dinosaurs and feathers, combined with the fact the first archosaurs probably had protofeathers and were warm blooded, else it might perpetrate the BAND theory.

"Dinosaur" is a scientific term meaning anything in the clade Dinosauria.If you let stupid colloquialisms in, then it would make pterosaurs, plesiosaurs, mosasaurs, itchyosaurs dinosaurs which none of them are. Plus, the lede explains the choice why it refers to birds as such. Doing anything else would make it more wordy.

~2026-17247-67 (talk) 21:30, 19 March 2026 (UTC)

You are still imposing rules on English words that simply do not exist. You may wish that they were used in that way, but they aren't (exclusively). Anyways, it's kind of beside the point. The current version of the second paragraph is acceptable to me, even if I think it is super unnecessary compared to just saying something like "birds evolved from dinosaurs" which means the same thing and communicates it in a much clearer and more concise way. But it's clear to me that there are a lot of people that really need it to literally say "birds are dinosaurs" for reasons that are still unclear to me. What I have a serious problem with is calling birds dinosaurs in the first sentence of the article. The fact that birds are members of this otherwise extinct group is way less important than their basic characteristics and relations to other living animals, which is what that introductory sentence should communicate. Somatochlora (talk) 11:55, 20 March 2026 (UTC)

Somatochlora, then please communicate the vertebrate data and other basic characteristics in the first sentence, but leave the long-term (4 1/2 months in the lead sentence) dinosaur descriptor, which also qualifies as a basic characteristic, there as well. No need to diminish the basic fact: birds are dinosaurs. Didn't evolve from dinosaurs. The only living dinosaur. An amazing story of species survival and distribution as well as daytime air domination (bats usually have the night air to themselves, but a few birds share that space). Wikipedia point to two branches of dinosaurs: the avian and the non-avian. Continuing lead sentence worthy. Randy Kryn (talk) 15:45, 22 March 2026 (UTC)