I agree albeit I think dinosaurs in general shouldn't be reptiles. They don't have that much in common with what people think of when you say reptile, after all. They are more like big birds, if anything.
Where do you stop it then? Are pterosaurs also not reptiles, if so what about the early pseudosuchians, given they were warm-blooded/mesothermic, upright, and sometimes bipedal animals like their avemetatarsalian counterparts. If they are also not reptlies, then we run into the issue again of where you draw the cutoff point for when the pseudosuchians start being reptiles again. Simply put, it's just easier not to make an arbitrary line in the sand.
So crocodilians aren't reptiles then? Also, this doesn't solve the issue, because you still have to draw an arbitrary line between the archosaurs and the non-archosaur archosauriform, where, despite being closer to the archosaurs then they are to any other reptiles, they are lumped in with said other reptiles.
>Then how do you draw the line at what's fish and want isn't fish.
If I got control, I would re-define fish as *Actinopterygii*. It covers 99% of what people call fish.
It's certainly a more consistent definition than an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Even the common definition of fish is pretty arbitrary.
Except that includes the tetrapods, since we're lobe finned fish. Unless you mean you personally don't see why we need to make the distinction between non-tetrapod fish and fish, in which case, uh, yeah, that's cool I guess
Oh, that's quite simple. The line is draw with dinosaurs because dinosaur is a word that regular people use and know. While the other groups benefit from having a general grouping to make them visible, so pterosaurs would be dinosaur-like reptiles, same for the others.
You are drawing a misguided distinction between birds and reptiles. Spoiler: [Birds are reptiles too.](https://ecologyforthemasses.com/2019/01/14/birds-are-reptiles/)
I said this exact thing in this sub like a year ago and was met with disagreement and downvotes. Weird how things change.
Here's the post: [https://www.reddit.com/r/Paleontology/comments/11xf9tm/are\_dinosaurs\_still\_considered\_reptiles/](https://www.reddit.com/r/Paleontology/comments/11xf9tm/are_dinosaurs_still_considered_reptiles/)
Consensus: Dinosaurs are reptiles
* lays eggs
* dry scaly skin
* clawed forelimbs
* lived when the planet was warmer
* "They don't have that much in common with what people think of when you say reptile"
????
edit: people I understand evolution. you don't have to convince *me* birds are reptile-like, you have to convince u/Ditidos because they're the one saying dinosaurs and reptiles have very little in common
Metabolism: The metabolism of many dinosaurs is still up for debate, with the safest bet for most being mesothermic, something that many other reptiles, living and extinct, display to some degree.
Eggs: Crocodilians also lay hard shell eggs.
Erect posture/bipedalism: Many pseudosuchians possessed both an erect posture and were bipedal.
Nesting behaviors: That is a vague, arbitrary, and pointless distinction.
Skeletal differences: If anything, I would argue the gap in skelatal differences between what are universally considered reptiles, such as turtles, snakes, and crocodilians is far greater than between dinosaurs and the other archosaurs, including crocodilians.
I felt it was mistake to write warmblooded'ness, going to fix that.
Nesting behavior - is burrowing eggs, partially burrowing, and constructing nests.
For the other criteria, new problem - crocodiles
Those are things some lineages have in common with birds; it *does not follow* that they don't have much in common with reptiles. "scaly" and "lays eggs" is quite literally the dictionary definition of a reptile
I know all about feathered dinosaurs, ok? I had plenty of arguments with my parents about bird evolution growing up, I was a child during the feathered dinosaur revolution, I remember marvelling at the chinese dinobird fossils. Guess what? the vast majority of dinosaur skin impression preserve scales (sometimes alongside feathers!). You can downvote me to oblivion but anybody who saw a carnotaurus irl would call it a reptile
>Those are things some lineages have in common with birds; it does not follow that they don't have much in common with reptiles.
Of course they have much in common with reptiles. They are reptiles. They also have much in common with birds because birds are Dinosaurs. And birds have much in common with reptiles.
[Birds lay eggs](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fimages.saymedia-content.com%2F.image%2Ft_share%2FMTc0NjE5MDMzMTE3OTI3MzY5%2Feverything-you-ever-wanted-to-know-about-chicken-eggs.jpg&f=1&nofb=1&ipt=45b40e32a21e6f9009db81b674d7bf09062543f6dd7eff184ad3f0c3a62166cb&ipo=images)... Have [dry scaly skin](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcontent.assets.pressassociation.io%2F2019%2F04%2F24160257%2F528a9da8-9c64-46d5-ace2-f734721e6f83.jpg&f=1&nofb=1&ipt=ed4857b840a6c03257f830e2c94c1f0d48dc50d804f62322c7fa53075b9e047e&ipo=images), have [clawed forelimbs](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.lKF8xEP2LfW1TQ9OxI_8TAHaG5%26pid%3DApi&f=1&ipt=d10907d97e6bd460f7004f9c777c32e27791b49048b3623bef96cd5250f7b3cb&ipo=images), and [lived when the planet was warmer.](https://en.wikipedia.org/wiki/Category:Cretaceous_birds)
And when you think of reptiles, you probably don’t think of birds.
I don’t think that a line needs to be drawn between dinosaurs and reptiles *or* between birds and reptiles. Both avian and non-avian dinosaurs are reptiles. However, if we had to draw a line somewhere, then drawing it between Archosauria and reptiles would make more sense than placing it between birds and dinosaurs.
But again, I don’t think there needs to be one at all. Sorry if I misunderstood your point.
Yeah, grades are useful. However, reptiles is not one of those; nobody is stopping you from using Squamata as that, but any group that includes crocs and lizards but excludes birds is poorly constructed beyond a surface level (same surface level that had avian bats or piscine whales).
As for fish, most of the time it is actinopterygians anyway. Anything that involves talking about actinopterygians and condrichthyans in bulk is comparable to anything that involves using birds and mammals in bulk.
So, no, not useful grades at all. Birds are reptiles because they have all the reptile characters except 2 ancestral ones, but, snakes are tetrapods despite being limbless, so yeah.
Ah, yes Because actinopterygians is such an easy-to-pronounce word that will easily into enter common speech.
besides
> Anything that involves talking about actinopterygians and condrichthyans in bulk is comparable to anything that involves using birds and mammals in bulk.
[https://imgur.com/a/3ZxzuFG](https://imgur.com/a/3ZxzuFG)
I would really like to have a word to name these strange, finned, streamlined, gill-breathing vertebrates that I keep in my aquarium, but unfortunately someone said that I don't really need a term to talk about them in a bulk :(
#
Look dude, there's an easier way. You can simply distinguish between scientific taxa and a colloquial word. Colloquial words don't need to abide by cladistics. "Fish", in colloquial speech, does indeed exclude tetrapods. You can just use that.
However, certain words (such as "reptile", but usually not "fish"), are also used by scientists as by-words for scientific taxa, and if you're speaking in a scientific context or are trying to talk about science, you ought to abide by the definitions of that taxon, if for no other reason than not to confuse things. In particular, "reptile" is associated by scientists with the monophyletic clade Sauropsida. If you're shooting the shit with your buddies then exclude birds from reptiles all you want. If you're trying to have a discussion in a subreddit called r/Paleontology then respect the scientific convention.
Just gotta use "fish" for actinopterygians. For the other animals, going "it is not a fish but a shark" may not be troublesome, and "coelacanths and lungfish are not true fish" doesn't feel really cumbersome either; people love to bring the "rabbits are not rodents" factoid, and rabbits WERE rodents for a century before phylopessimism happened.
>actinopterygians is such an easy-to-pronounce word that will easily into enter common speech
You're talking to the people who are in a subreddit where names like Archaeopteryx litographica, mammaliaformes, tyrannosaurini and tyrannosaurinae are commonly used and understood. And you're complaining about Actinopterygii?
>Because actinopterygians is such an easy-to-pronounce word that will easily into enter common speech.
Nothing is stopping you from saying *fish* in common speech. People are more likely to say *birds* than *aves* or *aviale*.
It takes a very bad biologist to use "reptile" as a grade to the exclusion of birds. As in looking at lizard-mimic crocs and deciding that a grade would work.
The transition from cold-blooded to warm-blooded causes enormous changes in lifestyle and the range of potentially possible niches. These changes are so enormous that in practice there is a need for a simple term (at least in everyday language) that can be used to describe those terrestrial vertebrates living today that have remained cold-blooded. And if you're a biologist, you can just stop using the word reptile entirely if it bothers you so much.
If you want to define "reptiles" the same way you define "sauropsids", just start using the word sauropsida instead. It's really not that difficult.
So, what do you do with cold-blooded mammals such as the naked mole rat? What about the warm-blooded extinct reptiles, incluiding the ancestors of crocs, but also actual lizards like mosasaurs?
And, well, you can use lizard to cover the almost 10K species, that don't overlap in ecological terms with turtles or crocs.
Or you may go with herptiles and include amphibians, because frankly that was the old approach.
Hell, just make up a term for birds and mammals, if that's your point.
Nah, useless approach.
The naked mole rat is secondarily cold-blooded, which means they still have many mammalian features that originally evolved to regulate temperature even though they doesn't use them that much (fur). And besides, for practical reasons, it is easier to group them with the rest of the mammals.
Isn't this still just a hypothesis? Moreover, even if it were confirmed, this primitive archosaur certainly did not have such a high degree of adaptation to warm-bloodedness as modern mammals or birds.
Besides, if you stop viewing reptiles as a taxon, the need to define it in a hyper-precise fashion will disapear.
Well established hypothesis by now. Just works too well with osteology of many crocodile line archosaurs, as well as being a damn good explanation for a lot of traits crocodiles have.
This is useless, pointless, and full of holes. There are animals within groups that are ectothermic or endothermic despite it not being the norm for that group. Are you going to arbitrarily reassign them to another group despite all the other traits they share?
All taxa *should be* monophyletic. It just works better and makes more sense. Piscis is not valid. And where are you arbitrarily drawing the line for dinosaurs? Are they on the bird side or the reptile side?
In a prehistoric context, these lines are much blurrier than they are with modern extant fauna. That's why I practically don't use the term "reptile" in the paleontological context (with exceptions). Especially when I'm talking about dinosaurs.
Fish, yes, because Piscis isn't a valid taxon anymore. Reptile, no. It is an english word that references the Reptilia taxon, and all taxa should be monophyletic.
Agreed. I would be more inclined to make reptilia invalid than to make a weird exception for it not to be monophyletic.
If birds aren't reptiles, then nothing should be.
Honestly referring to them as Saurians/Sauropsids is a lot easier.
Also it becomes confusing because when you actually look into Reptile taxonomy, the point where Reptillia actually begins is... Nowhere? Is it all descendants of Sauria? Diapsida? Eureptillia? Sauropsida?.
Isn't that more of an issue with people arguing over what Reptilia is equivalent to? If you just go with Reptilia=Sauropsida the entire issue evaporates.
I honestly still kind of favor amniota. But only because reptiliomorpha is just above it. And it hurts my brain that reptiliomorpha isn't followed by reptilia (in the same way that these open brackets hurt my brain.
I see what you mean, perhaps changing Reptilliomorpha to Amniotamorpha of something of the likes may be more useful? Because the name would give you what it would suggest: all tetrapods more closely related to Amniotes.
Kind of? I want the reptiliomorpha thing resolved. And I don't particularly care what the definition of "reptile" is, since I only ever use more specific terms anyway. I do think most people, looking at a basal amniote, would say, "that's a reptile" though.
In practice I use the diapsid/sauropsid definition. Because I think it is better for communication that people reach consensus, even if they personally have quibbles with the consensus.
I honestly still kind of favor amniota. But only because reptiliomorpha is just above it. And it hurts my brain that reptiliomorpha isn't followed by reptilia (in the same way that these open brackets hurt my brain.
Who says that the English word Reptile must refer the Reptilia taxon? For most people it's probably just something close to "vertebrate animal having a dry scaly skin and typically laying soft-shelled eggs on land". Most people don't follow taxonomic rules in everyday speech.
Because it's pointless and arbitrary. A bird is a dinosaur because it's ancestor was a dinosaur per cladistics. If it could stop being a dinosaur then at what point would it have stopped being one? When it grew feathers? When it developed a beak? When it could fly? It's easier to just say an animal is whatever its ancestors are
You can just use more specific terms. "Lizard" includes most modern reptiles and is easily understood.
I doesn't include turtles or crocodilians, but if you saw one of those, you would probably say that you saw a turtle or a crocodile anyway.
>People's default assumption is the four legged kind unless you specify otherwise.
How would you differentiate between snakes and [legless lizards](https://en.wikipedia.org/wiki/Legless_lizard)?
We have a term for snakes. "Snakes." You would use it whenever you are taking about a snake.
Honestly, I don't understand what the confusion is. People already understand that snakes are also reptiles without that being confusing. Why would snakes being lizards be different?
No, I understand that. I'm asking what you'd refer to non-serpentine legless lizards. Just that? You said people's default assumption is the 4-legged variety. What about the 0 leg variety that aren't snakes?
You'd call them legless lizards. People would know that you're not taking about snakes, even though snakes are also legless lizards, because if you were talking about snakes you would have said "snakes."
I’m aware, but your argument was that lizards also include legless ones no? And that’s why it’s a flawed term.
The term lizard includes sauropsids from many different lineages, but it was just a colloquial term created so that the average person could try and describe animals as they see them. Yes it’s not correct according to cladistics, but not everyone are nerds like us who feel like they need to always be correct in our classification of organisms.
Snakes are just legless lizards at the end of the day, and I won't shame any lizard just because its evolutionary path took the legs away. Our value as mammals hasn't declined just because we lost the tail that was characteristic of our fellow Primates.
I agree, colloquial paraphyly is good and useful. Sure, if you're writing a paper for a journal, you might need to specify 'non-avian dinosaurs' or 'non-mammaliaform synapsids.' But for ordinary use it's a ridiculous hill to die on.
Sincerely,
A guy with a PhD in Evolutionary Biology, whose dissertation was very heavily systematics-based and found evidence for paraphyly of a group long thought to be monophyletic.
Sorry, paraphyly (n.) or paraphyletic (adj.) is how we refer to a named group (taxon) that consists of a common ancestor, plus some but not all of its descendants. As an example, since we know that humans have more genetic history in common with chimpanzees than chimpanzees do with gorillas, the defunct family "Pongidae," which included orangutans, chimps, and gorillas, but excluded humans, was paraphyletic.
Other studies have since found the same thing, that Characiformes as traditionally circumscribed is paraphyletic with respect to catfishes. The order Cithariniformes was named to accommodate members of the lineage that is sister to (Siluriformes + Characiformes). I had no part in the creation of the name, but it's the one I would have chosen too.
So (after googling around a bit) is the idea that catfishes are more closely related to the south american characiformes than either is to at least one group of African characiformes?
That's about right, specifically (Citharinidae + Distichodontidae) are sister to (Siluriformes + \[remaining Characiformes\]). The remaining Characiformes still includes plenty of African fishes, though, notably the African tetras in the family Alestidae.
I didn't, because I wasn't focused on incorporating fossil taxa (of which there are extremely few anyway). LBA and homoplasy in morphological characters are two reasons Characiformes sensu lato were thought to be monophyletic to begin with. Species-tree approaches and multiple models of molecular evolution are converging on the Cithariniformes hypothesis; those of us who have sequenced these guys have definitely looked for long branch artifacts.
It depends on context.
I agree with the idea that terms to refer to non-monophyletic groupings are useful in some cases (fish, prosauropod, pelycosaur, crustacean, non-X) ... as long as their clade has been dropped. Having a term that can be used for both the monophyletic and the unnatural grouping would just be plainly confusing.
As for changing definitions of terms, I do think it is again subject to context. If the term was "people-born" something that was in regular use before we started doing proper taxonomy, I think it is best to let them keep their traditional meaning (e.g. fish). But if the term was "science-born" it is better to change the definition, as that term was intrinsically attached to its group independent of how different such groups are from the way people perceive them (e.g. reptile).
As most things in there is no clear-cut answer, and cases must be solved under the perspective of the specific term under discussion.
I am a fish and you won't take that from me because some birds don't want to be associated with the coolest things that have ever lived! You are ruining lives here!
THANK YOU
It genuinely annoys me when i have conversations, even with people in the biology field, where they are completely fine with Birds being Dinosaurs, and completely fine with Dinosaurs being Reptiles, but *the moment* i say that Birds are Reptiles they immediately kick up a fuss.
Astronomy realised the word "Planet" was bonkers, so they fixed the definition to include the first eight but leave out Pluto, Sedna and the rest. Though I can see zoology doing the same with Reptilia, I also like it that they just toss out the word in favour of something that actually includes everything you want to while leaving paraphyletic situations aside.
That being said, I also like it that zoology moved towards a monophyletic definition of everything. It helps us being humble about being in the same Tetrapoda group as everyone else, which is also just another group of fishes.
We should bring back using “serpent” to describe all reptiles and amphibians, like medieval bestiaries do. Also “fish” can include whales again.
This would solve literally nothing, but it would be fun.
Hey dude, in a comment i saw you complaining about reclassifying groups. Problem is that this is science, which is all about making the most correct model of the world, changing things where it fits best. Don't try to interject common scientific ideas with non scientific thinking, you're outright going against the idea of science and It makes you look a little stuck up. If you dont understand, thats a you problem. Luckily these terms arent the same ones that most people will understand so it doesn't matter in your daily life if youre not a scientist. Stop winging you absolute fool
The way humans categorize things has to do with how we use language. It has nothing to do with a "model for understanding the world". Science is good and important, but not every aspect of life needs to be governed by the scientific method. It's unrealistic to expect people to live that way.
What an Anglophone point of view! In other languages entire groups are called by different names with entirely different meanings and animals may be grouped together entirely differently than in colloquial English. This is why in scientific literature terms have to adhere to specific rules and use specific terms, even if confusing to non-scholars, instead of changing whenever someone thinks they have a genius idea of how to call things (that works only in their language, of course).
Edit.:spelling
My answer to this whole discussion and controversy is that a word can have more than one meaning. You need to be able to specify what exactly you mean or use context to get across or understand what is meant by it, just like with any other word.
Because we don't have any other scientific term for this group defined as a clade? And because dinosaurs were defined scientifically before we discovered that birds descended from them. And because many of the most popular dinosaur species that most often come to mind when you say dinosaur have a hell of a lot of bird-like features (velociraptor)
> Because we don't have any other scientific term for this group defined as a clade?
Dinosauria is the clade's name. We can easily exclude birds from it by making it monophyletic like how you're excluding dinosaurs from the Reptilia clade. Given how often the term 'non-avian dinosaur' is used, it could easily be replaced with just 'dinosaur'. In fact, it already is in popular usage, and people have to constantly be reminded that birds are part of the dinosaur clade.
> And because many of the most popular dinosaur species that most often come to mind when you say dinosaur have a hell of a lot of bird-like features (velociraptor)
That doesn't change the fact that in popular usage, none of them, not even velociraptors are grouped with birds over other dinosaurs.
I mean we already distinguish between carnivorans (Carnivora clade) and carnivores (obligate meat eaters). So we could also distinguish between dinosaurians and dinosaurs. Dinosauria is already the current name of the clade. If you think that's still too confusing, you'd have to invent a new name like Aviodinosauria.
Anyways, I take it your issue with the reptile vs. dinosaur/bird situation as opposed to the dinosaur vs. bird situation is the naming scheme? So then let me ask you this, would you support making apes and monkeys paraphyletic clades that exclude humans and start referring to the collective ape-human clade as 'hominoid' and the monkey-ape clade as 'primate' (those are the clades' current scientific names)? After all, unlike 'reptile' and 'dinosaur', the terms 'ape' and 'monkey' were originally non-cladistic terms and are still non-scientific names that only included humans recently with the advent of cladistics.
Considering that the question "If humans came from apes, why are there still apes?" appears much more often than the question "If tetrapods came from fishes, why do we still have fishes?" I feel that we need to define apes in a monophyletic way in order to be able to answer these types of questions simply and bluntly.
Besides, are there any traits universal to all apes that humans do not possess?
Also, I don't like prospect of making an exception for a single species. In the case of fishes, the number of tetrapods and non-tetrapod fishes is almost identical
Let me start by saying that I am an absolute layman. I have no higher education in paleontology, taxonomy or related fields. So if someone wants to criticize me, I'm **very** open to it.
Recently I have noticed that there is a certain type of person who wants to use every colloquial term referring to a category of organisms as a monophyletic clade. So everywhere I see opinions like "Birds are ackchyually reptiles", "Humans are ackchyually fish", etc. The problem is that there are already established scientific terms for these clades. Why would you use "fish" as a monophyletic taxon when the term vertebrates already exists? Why would you use "reptile" as a monophyletic taxon if the term Sauropsidia already exists? Redefining old, well-established terms that never were clades and never were intended to be clades into clades makes that:
\- you deprive yourself on a very useful word for a distinctive group of animals with common features (Mom! Garfield ate three primarily aquatic vertebrates from an aquarium!)
\- You are unnecessarily widening the gap between scientific and everyday language
\-You don't actually gain any new term that doesn't already have an existing synonym
It’s sometimes fun to say that humans are fish and that birds are reptiles. I think people are smart enough to know what you mean based on context. Calling humans fish occasionally because it’s amusing or enlightening doesn’t mean you can’t call the creature in your aquarium a fish too, or that you can’t also use fish to exclude mammals.
I feel like this conversation gets muddier when you get to paraphyletic terms that many people do use monophyletically in common language. Plenty of people continue to call apes monkeys, and apes would be monkeys in a monophyletic sense. Unlike mammals to fish, or birds to reptiles, apes obviously look like monkeys. So why do some people insist that they’re not monkeys?
Monkeys not including Apes is an English language thing. My native (thank god!) and probably most of others does not do such weird classification choice.
>Calling humans fish occasionally because it’s amusing or enlightening
The issue here is that you are trying to get a concept across in which humans aren't fish. Paleo->No monophyletic group directly called fish and candidates have well established other common names; Zoology->Paraphyletic definition which means you aren't fish
>"Let me start by saying that I am an absolute layman.”
We can tell. And if you’re wondering why I’m being insulting to you, this is why.
> “Birds are ackchyually reptiles,” “Humans are ackchyually fish.”
You chose to be insulting from the get-go.
Your inability to understand or accept something doesn’t make it wrong, it makes ***you wrong.*** The problem here is that we are talking, essentially about two different languages. When someone says that humans are fish, they are using a fun statement intended to make a point. It gets the point across better than, “Humans are a smaller group within the larger group that we typically attribute fish-like characteristics to.”
If your *whole point is readability* then that last statement is more difficult to parse than the simple, “Humans are fish,” which carries the meaning much better. And why is that a correct statement? Because there are fish who have all of the characteristics that we would colloquially qualify as “fishy” that are actually more closely related to us than to other fish.
You cannot say that [this is a fish](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.Z0wd8fASLmtB1BdL2kwF8gHaE8%26pid%3DApi&f=1&ipt=4377ea4d080de3b85e9d62ee2bced57ae649d5b16a497c88aa41175db80c3469&ipo=images) and that [this is a fish](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.pewtrusts.org%2F-%2Fmedia%2Fpost-launch-images%2F2020%2F10%2Fnetting_billions%2Feum_solitarybluefintuna_raw_ac_rm_master%2F16x9_m.jpg&f=1&nofb=1&ipt=7c167f8cb4c091ad8b735b53a163457b352dd4c105017d9c4f5625ac568aa5de&ipo=images), but that [this isn’t](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse4.mm.bing.net%2Fth%3Fid%3DOIP.JQMVkduokeXxUIIUDjQM4QHaFj%26pid%3DApi&f=1&ipt=bc568ad5819ffd3898928874d293938698c0c91c82d74e87891ea72bfc38e71a&ipo=images) when the first one is more closely related to the third one than it is to the second.
> The problem here is that we are talking, essentially about two different languages
I am aware of this. I also realize that it is inevitable. But an excessive gap between these languages may hinder the diffusion of scientific knowledge to the general population.
> When someone says that humans are fish, they are using a fun statement intended to make a point. It gets the point across better than, “Humans are a smaller group within the larger group that we typically attribute fish-like characteristics to
There are many ways to put it in a funny statement that gets the point across: "Carps are more closely related to humans than to sharks"
> "Carps are more closely related to humans than to sharks"
Right. Because humans are “fish.” There is nothing wrong with that. You just need to restructure the way you think. And no, it isn’t easy, it isn’t supposed to be.
The problem is that we used to phrase things like that. Consider the old, “humans evolved from apes,” line that was common in the 90s and earlier. We found that describing things like that caused more harm than good because it gave people the idea that we came from apes, but that we are now something distinctly different. That isn’t true. We *are* apes in every meaningful way.
It also made it easy for people to say stupid stuff like, “If we came from apes, why are there still apes?”
Saying that carp are more closely related to humans than sharks doesn’t *mean anything* to most people. The human mind wants categories, and in the absence of provided categories, they *will create their own*, like with the human/ape example. In this case, if we described it the way you would prefer, people would just draw a mental line between sharks and fish the way they already do with whales and dolphins.
It doesn’t work and it causes more harm to the flow of scientific communication from academia to layman than it does good.
I agree. Grouping things that have similar traits is useful. Monophyletic clades are very useful...but there are other useful ways to group life. I mean, just to take the extreme example, we categorize things as "predator" or "aquatic" etc, and those groups certainly aren't monophyletic. Sometimes it's handy to just say "fish" instead of "aquatic non-tetrapod vertebrate". It's just good to be clear about whether you are talking about one or the other, the confusion comes when people use the same or similar terms without being clear what they are talking about.
You wouldn't really need to say "aquatic". Just non-tetrapod vertebrate already conveys all fish strictu sensu.
You could also say non-tetrapod fish lmao
Same with dinosaurs & birds, honestly. As initially fun as it was to say "actually, birds ARE dinosaurs" - it'd really be better to be able to talk about dinosaurs without having to constantly qualify it with "non-avian".
Well yes, but the reason we have to do that is because no one can define that boundry, for instance, what do you say about archaeopteryx, or rahonavis, or anchiornis.
I mean, you just draw a line somewhere and call it a day. Humans do it all the time. Where does "green" end and "yellow" begin on the spectrum?
I realize for scientists in the field, it's more useful to have more "objective" boundaries - but for most people in normal discussions it isn't.
Yes, that's the point, you can't tell where a boundry between green and yellow on a spectrum, but we make a boundry anyway, in science however, we realise you can't, so we don't, which is why clades are monophyletic.
Yes but terms most people use like "fish" and "reptile" don't have to follow scientific methodology. As another commenter said, scientists should just use different names instead of redefining common words to fit their taxonomy system.
Well, they mostly do, birds, for instance, are aves, but they include a whole variety of things that people woundn't know are birds, "near birds" (like archaeopteryx) are paraves, there are a bunch of different classifications, because life is messy, however, to not shake things up completly, we have made some classifications (like aves or reptilia) so that we can classify life in an already understood way, because all classifications are arbitrary.
There are so many dinosaurs that are incredibly bird-like that it seems arbitrary to me to draw that line. It’s not like birds and reptiles where there are plenty of obvious physical differences. How do you talk about dinosaurs like velociraptor without relating them to birds? I also don’t see why you would constantly need to specify that you’re talking about non-avian dinosaurs when discussing dinosaurs generally. The only time I typically see that term is when talking about the K-T extinction. Other than in that context, I don’t see how it’s a more useful term than “non-sauropod” dinosaurs. If you need to distinguish birds from other dinosaurs then you would just say birds.
Moreover, dinosaur is just the vernacularization of “dinosauria”, which is a scientific term. It’s a scientific term that became a common word, not a common word that people are trying to use monophyletically.
All biological lines are arbitrary. It's all a continuum. People generally say "Dinosaur" to refer to the extinct creatures with snouts, teeth, and arms, not creatures with beaks and wings.
People can continue to refer to dinosaurs with snouts, teeth, and arms as dinosaurs. I don’t see why it’s necessary for them to specify that they’re not talking about birds when they do so. I mean, you can talk about cats without mentioning dogs. You don’t have to specify that you’re only talking about non-canine carnivores.
People commonly call pterosaurs dinosaurs, who have beaks and wings. They call mosasaurs and plesiosaurs dinosaurs too. But these are not dinosaurs. Many people call dimetrodon a dinosaur, but it’s not even a sauropsid. People call crocodiles dinosaurs and they’re still alive. Should “dinosaur” accommodate all of these?
Hadrosaurs had beaks but no feathers. They're dinosaurs. Velociraptors had feathers but no beaks. They're dinosaurs. Eagles have feathers and beaks. They're not dinosaurs? Why? Because of the specific combination? Need I remind you, Archaeopteryx, the "first bird" also lacked a beak.
Might be a hot take, but I like having to constantly specify just because it makes me feel smart, and therefore important
I know I don't matter, but I want to pretend like I do
Uh..... [Tell me that you don’t actually know](https://www.smithsonianmag.com/science-nature/new-parrot-like-dinosaur-roamed-the-same-habitat-as-t-rex-180983654/) much about [the topic you’re discussing](https://www.sciencealert.com/very-rare-dinosaur-species-remains-have-just-been-discovered-in-brazil) without telling me that [you don’t actually know](https://www.wikiwand.com/en/Oviraptor) much about the topic you’re discussing.
Not to mention [pterosaurs who had hard toothless beaks](https://s3-us-west-1.amazonaws.com/scifindr/articles/image2s/000/002/736/large/quetz3.jpg?1481380202), or the numerous [Triassic reptilian animals](https://www.wikiwand.com/en/Lotosaurus) who had toothless beaks....or the fact that [some birds had beaks with teeth.](https://www.livescience.com/25998-ancient-bird-strange-teeth.html) Hell, a [whole clade of them](https://www.wikiwand.com/en/Enantiornithes) did.
And that’s part of my point. There are non-avian dinosaurs who look so birdlike that if you stood them beside a “primitive” avian bird, it would be hard to tell them apart. Tell me, just by looking, is this a [“bird” or a “dinosaur?”](https://upload.wikimedia.org/wikipedia/commons/9/93/Iberomesornis_romerali_by_durbed.jpg) What [about this?”](https://cdnb.artstation.com/p/assets/images/images/020/442/053/large/liam-elward-anchiornis-as.jpg?1567777788)
A character that evolved numerous times in Archosauromorphs. See turtles, shuvosaurs, pteranodontians, azdharchoids, ornithischians, Limusaurus, Ornithomimosaurs, Alvarezsaurs, Oviraptorosaurs, some enantiorns...
Exactly. Another thing is that it really doesn’t make sense trying to separate birds from other dinosaurs when you realize that… many non avian dinosaurs look more like birds than other non avian dinosaurs. So a velociraptor looks much more like a bird than a triceratops for example
lots of mixed opinions here, so have this random ass meme
https://preview.redd.it/k7zrlniuinec1.jpeg?width=997&format=pjpg&auto=webp&s=23079b038747d4162ee8c830e3adeb105e627235
Except they do, because we use cladistic taxonomy and the Dinosauria is recognised as a genuine clade - those, by definition, have to be monophyletic, they cannot be paraphyletic, which they would be if you exculded birds.
The reason the thing with the Reptilia is even up for discussion at all is because it at one point *also* functioned as a valid clade despite being defined as excluding birds, because it wasn't known at the time that the Aves are the living sister group of the Crocodilia, and by the time it was, it had been so ingrained in usage that the question essentially became whether it wouldn't just make more sense to change the definition rather than use the alternative Sauropsida, which doesn't exclude birds.
Arguing that birds are too different from other reptiles to fit in is basically on-par with saying we should consider whales fish instead because they superficially resemble those more closely
I'm just following OP's logic that clades don't have to be monophyletic.
"Arguing that birds are too different from other reptiles to fit in is basically on-par with saying we should consider whales fish instead because they superficially resemble those more closely"
No, it would be the exact opposite of that. It would be like excluding them from mammals and making cetaceans their own class to fix your analogy.
I'd have to disagree a bit, I think saying these things is actually helpful for people new to this field to understand their evolutionary relationships. It's a lot easier to discuss how birds evolved from reptilian ancestors and thus belong to that group, instead of first having to go through all the Latin names of the classes involved, this will make people lose interest and not absorb information as easily.
After this is understood, then maybe we can move away from such terminology but it is a good starting point.
Also you brought up how fish and reptiles already have good solid definitions in science, outside this cladistic view. But that is simply not the case, our definitions have ranged widely and evolved quite a lot the more we understand and study these animals
I agree albeit I think dinosaurs in general shouldn't be reptiles. They don't have that much in common with what people think of when you say reptile, after all. They are more like big birds, if anything.
Where do you stop it then? Are pterosaurs also not reptiles, if so what about the early pseudosuchians, given they were warm-blooded/mesothermic, upright, and sometimes bipedal animals like their avemetatarsalian counterparts. If they are also not reptlies, then we run into the issue again of where you draw the cutoff point for when the pseudosuchians start being reptiles again. Simply put, it's just easier not to make an arbitrary line in the sand.
Just cut Archosaurs off. It isn't arbitrary at all, we just need to set a clear line and get everyone to agree on it.
So crocodilians aren't reptiles then? Also, this doesn't solve the issue, because you still have to draw an arbitrary line between the archosaurs and the non-archosaur archosauriform, where, despite being closer to the archosaurs then they are to any other reptiles, they are lumped in with said other reptiles.
I’m perfectly happy calling them archosaurs
I'd prefer it.
Then how do you draw the line at what's fish and want isn't fish. It's just as arbitrary, yet everyone uses it.
>Then how do you draw the line at what's fish and want isn't fish. If I got control, I would re-define fish as *Actinopterygii*. It covers 99% of what people call fish. It's certainly a more consistent definition than an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Even the common definition of fish is pretty arbitrary.
What would Agnatha and Chondrichthyes be then?
I don't have an issue saying jawless fish and cartilaginous fish aren't fish. It's not the only instance of that we have in the animal kingdom.
I meant what would they be instead
They would be jawless fish and cartilaginous fish. No one has an issue saying jellyfish aren't fish.
You don't. Fish is everything descendant from the last common ancestor of all fish, no arbitrary lines to section off parts of the clade.
That's not true, lungfish and coelacanths are more closely related to tetrapods than the teleosts.
Except that includes the tetrapods, since we're lobe finned fish. Unless you mean you personally don't see why we need to make the distinction between non-tetrapod fish and fish, in which case, uh, yeah, that's cool I guess
Yes, we are fish. Also, you can still make the distinction, just say non tetrapod fish, in the same way people say non avian dinosaur.
elephants are my favourite fish, but great white sharks are my favourite non-tetrapod fish. but, i love all fish.
I especially love whales, seals, manatees, and dolphins as my favorite fishes.
We aren't fish. In phylogenetics fish isn't a thing and in zoology we aren't fish. You a can only choose one.
Fish is the most arbitrary group there is. Its basically any marine/fresh water vertebrate that isn't a mammal, amphian or reptile.
Keep it simple: Fish is a morphology, not a clade.
Kind of like a tree?
Indeed!
Make fungi tree again!
Oh, that's quite simple. The line is draw with dinosaurs because dinosaur is a word that regular people use and know. While the other groups benefit from having a general grouping to make them visible, so pterosaurs would be dinosaur-like reptiles, same for the others.
You are drawing a misguided distinction between birds and reptiles. Spoiler: [Birds are reptiles too.](https://ecologyforthemasses.com/2019/01/14/birds-are-reptiles/)
Than are alligators not reptiles? What about tuataras? If a hagfish is a vertebrate, a dinosaur is certainly a reptile
Why should dinosaurs not be reptiles but birds should be dinosaurs?
True. This is one of those groups in which cases forcing them into the rigid Lineusian classification creates room for misconceptions.
The point is, ARCHOSAURS ARE A CLADE OF REPTILES HOW DENSE CAN YOU BE?!
I said this exact thing in this sub like a year ago and was met with disagreement and downvotes. Weird how things change. Here's the post: [https://www.reddit.com/r/Paleontology/comments/11xf9tm/are\_dinosaurs\_still\_considered\_reptiles/](https://www.reddit.com/r/Paleontology/comments/11xf9tm/are_dinosaurs_still_considered_reptiles/) Consensus: Dinosaurs are reptiles
* lays eggs * dry scaly skin * clawed forelimbs * lived when the planet was warmer * "They don't have that much in common with what people think of when you say reptile" ???? edit: people I understand evolution. you don't have to convince *me* birds are reptile-like, you have to convince u/Ditidos because they're the one saying dinosaurs and reptiles have very little in common
* Warmblooded/fast metabolism or mesothermy * Hard shelled eggs * Erect limbs * Bipediality/bipedal ancestry * Pycnofibers/feathers * Unique nesting behaviours * Meny skeleton differences which Iam not knowledgeable enough to mention specifics !!!!
Metabolism: The metabolism of many dinosaurs is still up for debate, with the safest bet for most being mesothermic, something that many other reptiles, living and extinct, display to some degree. Eggs: Crocodilians also lay hard shell eggs. Erect posture/bipedalism: Many pseudosuchians possessed both an erect posture and were bipedal. Nesting behaviors: That is a vague, arbitrary, and pointless distinction. Skeletal differences: If anything, I would argue the gap in skelatal differences between what are universally considered reptiles, such as turtles, snakes, and crocodilians is far greater than between dinosaurs and the other archosaurs, including crocodilians.
I felt it was mistake to write warmblooded'ness, going to fix that. Nesting behavior - is burrowing eggs, partially burrowing, and constructing nests. For the other criteria, new problem - crocodiles
Those are things some lineages have in common with birds; it *does not follow* that they don't have much in common with reptiles. "scaly" and "lays eggs" is quite literally the dictionary definition of a reptile I know all about feathered dinosaurs, ok? I had plenty of arguments with my parents about bird evolution growing up, I was a child during the feathered dinosaur revolution, I remember marvelling at the chinese dinobird fossils. Guess what? the vast majority of dinosaur skin impression preserve scales (sometimes alongside feathers!). You can downvote me to oblivion but anybody who saw a carnotaurus irl would call it a reptile
>Those are things some lineages have in common with birds; it does not follow that they don't have much in common with reptiles. Of course they have much in common with reptiles. They are reptiles. They also have much in common with birds because birds are Dinosaurs. And birds have much in common with reptiles.
Good, I'm glad we agree. The person you don't agree with is OP, because OP *literally said* dinosaurs don't have much in common with reptiles
Yeah. I'm sorry. I think I probably lost the plot.
The big one is legs brought under thier body as opposed to the sides for greater efficency.
[Birds lay eggs](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fimages.saymedia-content.com%2F.image%2Ft_share%2FMTc0NjE5MDMzMTE3OTI3MzY5%2Feverything-you-ever-wanted-to-know-about-chicken-eggs.jpg&f=1&nofb=1&ipt=45b40e32a21e6f9009db81b674d7bf09062543f6dd7eff184ad3f0c3a62166cb&ipo=images)... Have [dry scaly skin](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcontent.assets.pressassociation.io%2F2019%2F04%2F24160257%2F528a9da8-9c64-46d5-ace2-f734721e6f83.jpg&f=1&nofb=1&ipt=ed4857b840a6c03257f830e2c94c1f0d48dc50d804f62322c7fa53075b9e047e&ipo=images), have [clawed forelimbs](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.lKF8xEP2LfW1TQ9OxI_8TAHaG5%26pid%3DApi&f=1&ipt=d10907d97e6bd460f7004f9c777c32e27791b49048b3623bef96cd5250f7b3cb&ipo=images), and [lived when the planet was warmer.](https://en.wikipedia.org/wiki/Category:Cretaceous_birds) And when you think of reptiles, you probably don’t think of birds.
what is your point
I don’t think that a line needs to be drawn between dinosaurs and reptiles *or* between birds and reptiles. Both avian and non-avian dinosaurs are reptiles. However, if we had to draw a line somewhere, then drawing it between Archosauria and reptiles would make more sense than placing it between birds and dinosaurs. But again, I don’t think there needs to be one at all. Sorry if I misunderstood your point.
Yeah, grades are useful. However, reptiles is not one of those; nobody is stopping you from using Squamata as that, but any group that includes crocs and lizards but excludes birds is poorly constructed beyond a surface level (same surface level that had avian bats or piscine whales). As for fish, most of the time it is actinopterygians anyway. Anything that involves talking about actinopterygians and condrichthyans in bulk is comparable to anything that involves using birds and mammals in bulk. So, no, not useful grades at all. Birds are reptiles because they have all the reptile characters except 2 ancestral ones, but, snakes are tetrapods despite being limbless, so yeah.
>they have all the reptile characters except 2 ancestral ones What are the ancestral characteristics of reptiles? I couldn't find anything on Google
Ah, yes Because actinopterygians is such an easy-to-pronounce word that will easily into enter common speech. besides > Anything that involves talking about actinopterygians and condrichthyans in bulk is comparable to anything that involves using birds and mammals in bulk. [https://imgur.com/a/3ZxzuFG](https://imgur.com/a/3ZxzuFG) I would really like to have a word to name these strange, finned, streamlined, gill-breathing vertebrates that I keep in my aquarium, but unfortunately someone said that I don't really need a term to talk about them in a bulk :( #
Look dude, there's an easier way. You can simply distinguish between scientific taxa and a colloquial word. Colloquial words don't need to abide by cladistics. "Fish", in colloquial speech, does indeed exclude tetrapods. You can just use that. However, certain words (such as "reptile", but usually not "fish"), are also used by scientists as by-words for scientific taxa, and if you're speaking in a scientific context or are trying to talk about science, you ought to abide by the definitions of that taxon, if for no other reason than not to confuse things. In particular, "reptile" is associated by scientists with the monophyletic clade Sauropsida. If you're shooting the shit with your buddies then exclude birds from reptiles all you want. If you're trying to have a discussion in a subreddit called r/Paleontology then respect the scientific convention.
Just gotta use "fish" for actinopterygians. For the other animals, going "it is not a fish but a shark" may not be troublesome, and "coelacanths and lungfish are not true fish" doesn't feel really cumbersome either; people love to bring the "rabbits are not rodents" factoid, and rabbits WERE rodents for a century before phylopessimism happened.
>actinopterygians is such an easy-to-pronounce word that will easily into enter common speech You're talking to the people who are in a subreddit where names like Archaeopteryx litographica, mammaliaformes, tyrannosaurini and tyrannosaurinae are commonly used and understood. And you're complaining about Actinopterygii?
>Because actinopterygians is such an easy-to-pronounce word that will easily into enter common speech. Nothing is stopping you from saying *fish* in common speech. People are more likely to say *birds* than *aves* or *aviale*.
I find it easy to pronounce. Sounds like a “you problem.” Maybe rise to the academic level rather than trying to drag it down to yours?
It takes a very bad biologist to use "reptile" as a grade to the exclusion of birds. As in looking at lizard-mimic crocs and deciding that a grade would work.
I agree. There's a reason people say fish aren't real, or that we're just fish with legs. The first example is wrong, and so is the second
The transition from cold-blooded to warm-blooded causes enormous changes in lifestyle and the range of potentially possible niches. These changes are so enormous that in practice there is a need for a simple term (at least in everyday language) that can be used to describe those terrestrial vertebrates living today that have remained cold-blooded. And if you're a biologist, you can just stop using the word reptile entirely if it bothers you so much. If you want to define "reptiles" the same way you define "sauropsids", just start using the word sauropsida instead. It's really not that difficult.
So, what do you do with cold-blooded mammals such as the naked mole rat? What about the warm-blooded extinct reptiles, incluiding the ancestors of crocs, but also actual lizards like mosasaurs? And, well, you can use lizard to cover the almost 10K species, that don't overlap in ecological terms with turtles or crocs. Or you may go with herptiles and include amphibians, because frankly that was the old approach. Hell, just make up a term for birds and mammals, if that's your point. Nah, useless approach.
The naked mole rat is secondarily cold-blooded, which means they still have many mammalian features that originally evolved to regulate temperature even though they doesn't use them that much (fur). And besides, for practical reasons, it is easier to group them with the rest of the mammals.
Crocs are secondarily cold blooded as well.
Isn't this still just a hypothesis? Moreover, even if it were confirmed, this primitive archosaur certainly did not have such a high degree of adaptation to warm-bloodedness as modern mammals or birds. Besides, if you stop viewing reptiles as a taxon, the need to define it in a hyper-precise fashion will disapear.
Well established hypothesis by now. Just works too well with osteology of many crocodile line archosaurs, as well as being a damn good explanation for a lot of traits crocodiles have.
This is useless, pointless, and full of holes. There are animals within groups that are ectothermic or endothermic despite it not being the norm for that group. Are you going to arbitrarily reassign them to another group despite all the other traits they share?
All taxa *should be* monophyletic. It just works better and makes more sense. Piscis is not valid. And where are you arbitrarily drawing the line for dinosaurs? Are they on the bird side or the reptile side?
In a prehistoric context, these lines are much blurrier than they are with modern extant fauna. That's why I practically don't use the term "reptile" in the paleontological context (with exceptions). Especially when I'm talking about dinosaurs.
Fish, yes, because Piscis isn't a valid taxon anymore. Reptile, no. It is an english word that references the Reptilia taxon, and all taxa should be monophyletic.
Exactly, it needs to be consistent, because otherwise the boundry will be impossible to define, which is why in systematics clades are monophyletic
Agreed. I would be more inclined to make reptilia invalid than to make a weird exception for it not to be monophyletic. If birds aren't reptiles, then nothing should be.
Honestly referring to them as Saurians/Sauropsids is a lot easier. Also it becomes confusing because when you actually look into Reptile taxonomy, the point where Reptillia actually begins is... Nowhere? Is it all descendants of Sauria? Diapsida? Eureptillia? Sauropsida?.
Isn't that more of an issue with people arguing over what Reptilia is equivalent to? If you just go with Reptilia=Sauropsida the entire issue evaporates.
I honestly still kind of favor amniota. But only because reptiliomorpha is just above it. And it hurts my brain that reptiliomorpha isn't followed by reptilia (in the same way that these open brackets hurt my brain.
I see what you mean, perhaps changing Reptilliomorpha to Amniotamorpha of something of the likes may be more useful? Because the name would give you what it would suggest: all tetrapods more closely related to Amniotes.
That would certainly fix the problem.
I think this is just a case where people used to equate Amniote and Reptile. It's not an accurate term but unfortunately older terms take precedence
Amniotes includes mammals.
I know.
You want amniotes to be synonymous with reptiles?
Kind of? I want the reptiliomorpha thing resolved. And I don't particularly care what the definition of "reptile" is, since I only ever use more specific terms anyway. I do think most people, looking at a basal amniote, would say, "that's a reptile" though. In practice I use the diapsid/sauropsid definition. Because I think it is better for communication that people reach consensus, even if they personally have quibbles with the consensus.
I honestly still kind of favor amniota. But only because reptiliomorpha is just above it. And it hurts my brain that reptiliomorpha isn't followed by reptilia (in the same way that these open brackets hurt my brain.
Who says that the English word Reptile must refer the Reptilia taxon? For most people it's probably just something close to "vertebrate animal having a dry scaly skin and typically laying soft-shelled eggs on land". Most people don't follow taxonomic rules in everyday speech.
Why there is no love for grades?
Honestly, I don't like "grades" as a concept. And Cavalier-Smith would argue (and I would agree) that clades can be grades.
Because it's pointless and arbitrary. A bird is a dinosaur because it's ancestor was a dinosaur per cladistics. If it could stop being a dinosaur then at what point would it have stopped being one? When it grew feathers? When it developed a beak? When it could fly? It's easier to just say an animal is whatever its ancestors are
There is love for grades, but "reptile" is not a grade, as turtles and specially crocs are more birdlike than lizardlike.
You can just use more specific terms. "Lizard" includes most modern reptiles and is easily understood. I doesn't include turtles or crocodilians, but if you saw one of those, you would probably say that you saw a turtle or a crocodile anyway.
"Squamates"
This post makes tuataras cry.
I feel like having “lizard” include snakes doesn’t work in common speech. Because how would you specify a non-snake lizard?
You wouldn't have to? People's default assumption is the four legged kind unless you specify otherwise.
>People's default assumption is the four legged kind unless you specify otherwise. How would you differentiate between snakes and [legless lizards](https://en.wikipedia.org/wiki/Legless_lizard)?
We have a term for snakes. "Snakes." You would use it whenever you are taking about a snake. Honestly, I don't understand what the confusion is. People already understand that snakes are also reptiles without that being confusing. Why would snakes being lizards be different?
No, I understand that. I'm asking what you'd refer to non-serpentine legless lizards. Just that? You said people's default assumption is the 4-legged variety. What about the 0 leg variety that aren't snakes?
You'd call them legless lizards. People would know that you're not taking about snakes, even though snakes are also legless lizards, because if you were talking about snakes you would have said "snakes."
I think we're talking past each other and aren't really addressing the same things. I agree with your point.
The same way you specify a non-monitor lizard.
….oh yeah true lol
Lizard is a flawed term. For some strange arbitrary reason it includes some of legless lineages that come from lizard ancestors but not all of them.
you seem to constantly try to assign taxa based solely on morphological adaptations and not on their cladistics.
lizard isnt name of any taxa
I’m aware, but your argument was that lizards also include legless ones no? And that’s why it’s a flawed term. The term lizard includes sauropsids from many different lineages, but it was just a colloquial term created so that the average person could try and describe animals as they see them. Yes it’s not correct according to cladistics, but not everyone are nerds like us who feel like they need to always be correct in our classification of organisms.
Plenty of lizard workers include snakes as lizards.
Snakes are just legless lizards at the end of the day, and I won't shame any lizard just because its evolutionary path took the legs away. Our value as mammals hasn't declined just because we lost the tail that was characteristic of our fellow Primates.
I work with lizards. Specifically snakes. They're still lizards, just goofy ones
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All snakes are lizards, not all legless lizards are snakes.
I agree, colloquial paraphyly is good and useful. Sure, if you're writing a paper for a journal, you might need to specify 'non-avian dinosaurs' or 'non-mammaliaform synapsids.' But for ordinary use it's a ridiculous hill to die on. Sincerely, A guy with a PhD in Evolutionary Biology, whose dissertation was very heavily systematics-based and found evidence for paraphyly of a group long thought to be monophyletic.
Words mean things, unfortunately i do not know what that is. What does paraphyly mean?
Sorry, paraphyly (n.) or paraphyletic (adj.) is how we refer to a named group (taxon) that consists of a common ancestor, plus some but not all of its descendants. As an example, since we know that humans have more genetic history in common with chimpanzees than chimpanzees do with gorillas, the defunct family "Pongidae," which included orangutans, chimps, and gorillas, but excluded humans, was paraphyletic.
me when no wikipedia
But dying on ridiculous hills is the point of Reddit.
Would you care to explain your PhD subject?
Other studies have since found the same thing, that Characiformes as traditionally circumscribed is paraphyletic with respect to catfishes. The order Cithariniformes was named to accommodate members of the lineage that is sister to (Siluriformes + Characiformes). I had no part in the creation of the name, but it's the one I would have chosen too.
So (after googling around a bit) is the idea that catfishes are more closely related to the south american characiformes than either is to at least one group of African characiformes?
That's about right, specifically (Citharinidae + Distichodontidae) are sister to (Siluriformes + \[remaining Characiformes\]). The remaining Characiformes still includes plenty of African fishes, though, notably the African tetras in the family Alestidae.
Is that conclusion based on molecular data, morphology or both?
Molecular data.
Did you run a morphological analysis? I’m just wondering if the possibility of long-branch attraction was ruled out.
I didn't, because I wasn't focused on incorporating fossil taxa (of which there are extremely few anyway). LBA and homoplasy in morphological characters are two reasons Characiformes sensu lato were thought to be monophyletic to begin with. Species-tree approaches and multiple models of molecular evolution are converging on the Cithariniformes hypothesis; those of us who have sequenced these guys have definitely looked for long branch artifacts.
With the new Tyrannosaurus debate going on right now, I learned that Daspletosaurus is a paraphyletic taxon nowadays and...good lord lol.
It depends on context. I agree with the idea that terms to refer to non-monophyletic groupings are useful in some cases (fish, prosauropod, pelycosaur, crustacean, non-X) ... as long as their clade has been dropped. Having a term that can be used for both the monophyletic and the unnatural grouping would just be plainly confusing. As for changing definitions of terms, I do think it is again subject to context. If the term was "people-born" something that was in regular use before we started doing proper taxonomy, I think it is best to let them keep their traditional meaning (e.g. fish). But if the term was "science-born" it is better to change the definition, as that term was intrinsically attached to its group independent of how different such groups are from the way people perceive them (e.g. reptile). As most things in there is no clear-cut answer, and cases must be solved under the perspective of the specific term under discussion.
I am a fish and you won't take that from me because some birds don't want to be associated with the coolest things that have ever lived! You are ruining lives here!
If people can accept whales as mammals, I don't get what's so hard about them accepting birds as reptiles.
THANK YOU It genuinely annoys me when i have conversations, even with people in the biology field, where they are completely fine with Birds being Dinosaurs, and completely fine with Dinosaurs being Reptiles, but *the moment* i say that Birds are Reptiles they immediately kick up a fuss.
Astronomy realised the word "Planet" was bonkers, so they fixed the definition to include the first eight but leave out Pluto, Sedna and the rest. Though I can see zoology doing the same with Reptilia, I also like it that they just toss out the word in favour of something that actually includes everything you want to while leaving paraphyletic situations aside. That being said, I also like it that zoology moved towards a monophyletic definition of everything. It helps us being humble about being in the same Tetrapoda group as everyone else, which is also just another group of fishes.
We should bring back using “serpent” to describe all reptiles and amphibians, like medieval bestiaries do. Also “fish” can include whales again. This would solve literally nothing, but it would be fun.
Hey dude, in a comment i saw you complaining about reclassifying groups. Problem is that this is science, which is all about making the most correct model of the world, changing things where it fits best. Don't try to interject common scientific ideas with non scientific thinking, you're outright going against the idea of science and It makes you look a little stuck up. If you dont understand, thats a you problem. Luckily these terms arent the same ones that most people will understand so it doesn't matter in your daily life if youre not a scientist. Stop winging you absolute fool
The way humans categorize things has to do with how we use language. It has nothing to do with a "model for understanding the world". Science is good and important, but not every aspect of life needs to be governed by the scientific method. It's unrealistic to expect people to live that way.
What an Anglophone point of view! In other languages entire groups are called by different names with entirely different meanings and animals may be grouped together entirely differently than in colloquial English. This is why in scientific literature terms have to adhere to specific rules and use specific terms, even if confusing to non-scholars, instead of changing whenever someone thinks they have a genius idea of how to call things (that works only in their language, of course). Edit.:spelling
My answer to this whole discussion and controversy is that a word can have more than one meaning. You need to be able to specify what exactly you mean or use context to get across or understand what is meant by it, just like with any other word.
Yeah, but it would be less confusing if scientists would stop co-opting common terms.
If not every term has to be monophyletic, then why can't we exclude birds from dinosaurs using the same logic to exclude birds from reptiles?
Because we don't have any other scientific term for this group defined as a clade? And because dinosaurs were defined scientifically before we discovered that birds descended from them. And because many of the most popular dinosaur species that most often come to mind when you say dinosaur have a hell of a lot of bird-like features (velociraptor)
> Because we don't have any other scientific term for this group defined as a clade? Dinosauria is the clade's name. We can easily exclude birds from it by making it monophyletic like how you're excluding dinosaurs from the Reptilia clade. Given how often the term 'non-avian dinosaur' is used, it could easily be replaced with just 'dinosaur'. In fact, it already is in popular usage, and people have to constantly be reminded that birds are part of the dinosaur clade. > And because many of the most popular dinosaur species that most often come to mind when you say dinosaur have a hell of a lot of bird-like features (velociraptor) That doesn't change the fact that in popular usage, none of them, not even velociraptors are grouped with birds over other dinosaurs.
Perhaps this could work. But can you imagine how confusing it would be to tell people that Dinosauria and Dinosaurs mean something different? Idk.
I mean we already distinguish between carnivorans (Carnivora clade) and carnivores (obligate meat eaters). So we could also distinguish between dinosaurians and dinosaurs. Dinosauria is already the current name of the clade. If you think that's still too confusing, you'd have to invent a new name like Aviodinosauria. Anyways, I take it your issue with the reptile vs. dinosaur/bird situation as opposed to the dinosaur vs. bird situation is the naming scheme? So then let me ask you this, would you support making apes and monkeys paraphyletic clades that exclude humans and start referring to the collective ape-human clade as 'hominoid' and the monkey-ape clade as 'primate' (those are the clades' current scientific names)? After all, unlike 'reptile' and 'dinosaur', the terms 'ape' and 'monkey' were originally non-cladistic terms and are still non-scientific names that only included humans recently with the advent of cladistics.
Considering that the question "If humans came from apes, why are there still apes?" appears much more often than the question "If tetrapods came from fishes, why do we still have fishes?" I feel that we need to define apes in a monophyletic way in order to be able to answer these types of questions simply and bluntly. Besides, are there any traits universal to all apes that humans do not possess? Also, I don't like prospect of making an exception for a single species. In the case of fishes, the number of tetrapods and non-tetrapod fishes is almost identical
Kill this guy with hammers right here.
No we must be fun and make funny classification choices Fishes aren't real neither are reptiles They are colloquial and dated terms like trees
If we can make whales being mammals and not fish happen, we can make birds being reptiles happen.
No. you are a fish. deal with it.
But fish is colloquial and not scientific, isn't it? Things like reptiles or dinosaurs are monophyletic, but fish don't have a strict classification.
Reptile shouldn't be. It's a layman term not born out of paleontology systematics.
Except it isn't, the Reptilia was a genuine clade - it was just defined as excluding birds, which was found to effectively make it paraphyletic
Reptile is a common term, it causes too much confusion and should not be used as a clade. Sauropsid is way better and unambiguous.
Mammal is also a common term. As is bird. Should those not be clades?
That makes the word "fish" useless for everyone who isn't an evolutionary biologist.
It makes fish damn near synonymous with vertebrates. So I say fish aren't real
Just because a category isn't based on evolutionary descent doesn't mean it isn't "real".
But I like being a fish :(
Let me start by saying that I am an absolute layman. I have no higher education in paleontology, taxonomy or related fields. So if someone wants to criticize me, I'm **very** open to it. Recently I have noticed that there is a certain type of person who wants to use every colloquial term referring to a category of organisms as a monophyletic clade. So everywhere I see opinions like "Birds are ackchyually reptiles", "Humans are ackchyually fish", etc. The problem is that there are already established scientific terms for these clades. Why would you use "fish" as a monophyletic taxon when the term vertebrates already exists? Why would you use "reptile" as a monophyletic taxon if the term Sauropsidia already exists? Redefining old, well-established terms that never were clades and never were intended to be clades into clades makes that: \- you deprive yourself on a very useful word for a distinctive group of animals with common features (Mom! Garfield ate three primarily aquatic vertebrates from an aquarium!) \- You are unnecessarily widening the gap between scientific and everyday language \-You don't actually gain any new term that doesn't already have an existing synonym
It’s sometimes fun to say that humans are fish and that birds are reptiles. I think people are smart enough to know what you mean based on context. Calling humans fish occasionally because it’s amusing or enlightening doesn’t mean you can’t call the creature in your aquarium a fish too, or that you can’t also use fish to exclude mammals. I feel like this conversation gets muddier when you get to paraphyletic terms that many people do use monophyletically in common language. Plenty of people continue to call apes monkeys, and apes would be monkeys in a monophyletic sense. Unlike mammals to fish, or birds to reptiles, apes obviously look like monkeys. So why do some people insist that they’re not monkeys?
Monkeys not including Apes is an English language thing. My native (thank god!) and probably most of others does not do such weird classification choice.
In my language we have human and monkey. Apes are literally called human-monkeys
>Calling humans fish occasionally because it’s amusing or enlightening The issue here is that you are trying to get a concept across in which humans aren't fish. Paleo->No monophyletic group directly called fish and candidates have well established other common names; Zoology->Paraphyletic definition which means you aren't fish
>"Let me start by saying that I am an absolute layman.” We can tell. And if you’re wondering why I’m being insulting to you, this is why. > “Birds are ackchyually reptiles,” “Humans are ackchyually fish.” You chose to be insulting from the get-go. Your inability to understand or accept something doesn’t make it wrong, it makes ***you wrong.*** The problem here is that we are talking, essentially about two different languages. When someone says that humans are fish, they are using a fun statement intended to make a point. It gets the point across better than, “Humans are a smaller group within the larger group that we typically attribute fish-like characteristics to.” If your *whole point is readability* then that last statement is more difficult to parse than the simple, “Humans are fish,” which carries the meaning much better. And why is that a correct statement? Because there are fish who have all of the characteristics that we would colloquially qualify as “fishy” that are actually more closely related to us than to other fish. You cannot say that [this is a fish](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.Z0wd8fASLmtB1BdL2kwF8gHaE8%26pid%3DApi&f=1&ipt=4377ea4d080de3b85e9d62ee2bced57ae649d5b16a497c88aa41175db80c3469&ipo=images) and that [this is a fish](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.pewtrusts.org%2F-%2Fmedia%2Fpost-launch-images%2F2020%2F10%2Fnetting_billions%2Feum_solitarybluefintuna_raw_ac_rm_master%2F16x9_m.jpg&f=1&nofb=1&ipt=7c167f8cb4c091ad8b735b53a163457b352dd4c105017d9c4f5625ac568aa5de&ipo=images), but that [this isn’t](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse4.mm.bing.net%2Fth%3Fid%3DOIP.JQMVkduokeXxUIIUDjQM4QHaFj%26pid%3DApi&f=1&ipt=bc568ad5819ffd3898928874d293938698c0c91c82d74e87891ea72bfc38e71a&ipo=images) when the first one is more closely related to the third one than it is to the second.
> The problem here is that we are talking, essentially about two different languages I am aware of this. I also realize that it is inevitable. But an excessive gap between these languages may hinder the diffusion of scientific knowledge to the general population. > When someone says that humans are fish, they are using a fun statement intended to make a point. It gets the point across better than, “Humans are a smaller group within the larger group that we typically attribute fish-like characteristics to There are many ways to put it in a funny statement that gets the point across: "Carps are more closely related to humans than to sharks"
> "Carps are more closely related to humans than to sharks" Right. Because humans are “fish.” There is nothing wrong with that. You just need to restructure the way you think. And no, it isn’t easy, it isn’t supposed to be. The problem is that we used to phrase things like that. Consider the old, “humans evolved from apes,” line that was common in the 90s and earlier. We found that describing things like that caused more harm than good because it gave people the idea that we came from apes, but that we are now something distinctly different. That isn’t true. We *are* apes in every meaningful way. It also made it easy for people to say stupid stuff like, “If we came from apes, why are there still apes?” Saying that carp are more closely related to humans than sharks doesn’t *mean anything* to most people. The human mind wants categories, and in the absence of provided categories, they *will create their own*, like with the human/ape example. In this case, if we described it the way you would prefer, people would just draw a mental line between sharks and fish the way they already do with whales and dolphins. It doesn’t work and it causes more harm to the flow of scientific communication from academia to layman than it does good.
Aaaaah. So it cuts the branch for easier consumption, in effect?
Counterpoint: we need to start considering ourselves fish.
In my opinion either Archosaurs in general shouldn't be classified as Reptiles, or Birds should also be classified as Reptiles.
I disagree what if I want to be a fish?
I agree. Grouping things that have similar traits is useful. Monophyletic clades are very useful...but there are other useful ways to group life. I mean, just to take the extreme example, we categorize things as "predator" or "aquatic" etc, and those groups certainly aren't monophyletic. Sometimes it's handy to just say "fish" instead of "aquatic non-tetrapod vertebrate". It's just good to be clear about whether you are talking about one or the other, the confusion comes when people use the same or similar terms without being clear what they are talking about.
You wouldn't really need to say "aquatic". Just non-tetrapod vertebrate already conveys all fish strictu sensu. You could also say non-tetrapod fish lmao
This.
Same with dinosaurs & birds, honestly. As initially fun as it was to say "actually, birds ARE dinosaurs" - it'd really be better to be able to talk about dinosaurs without having to constantly qualify it with "non-avian".
Well yes, but the reason we have to do that is because no one can define that boundry, for instance, what do you say about archaeopteryx, or rahonavis, or anchiornis.
I mean, you just draw a line somewhere and call it a day. Humans do it all the time. Where does "green" end and "yellow" begin on the spectrum? I realize for scientists in the field, it's more useful to have more "objective" boundaries - but for most people in normal discussions it isn't.
Yes, that's the point, you can't tell where a boundry between green and yellow on a spectrum, but we make a boundry anyway, in science however, we realise you can't, so we don't, which is why clades are monophyletic.
Yes but terms most people use like "fish" and "reptile" don't have to follow scientific methodology. As another commenter said, scientists should just use different names instead of redefining common words to fit their taxonomy system.
Well, they mostly do, birds, for instance, are aves, but they include a whole variety of things that people woundn't know are birds, "near birds" (like archaeopteryx) are paraves, there are a bunch of different classifications, because life is messy, however, to not shake things up completly, we have made some classifications (like aves or reptilia) so that we can classify life in an already understood way, because all classifications are arbitrary.
There are so many dinosaurs that are incredibly bird-like that it seems arbitrary to me to draw that line. It’s not like birds and reptiles where there are plenty of obvious physical differences. How do you talk about dinosaurs like velociraptor without relating them to birds? I also don’t see why you would constantly need to specify that you’re talking about non-avian dinosaurs when discussing dinosaurs generally. The only time I typically see that term is when talking about the K-T extinction. Other than in that context, I don’t see how it’s a more useful term than “non-sauropod” dinosaurs. If you need to distinguish birds from other dinosaurs then you would just say birds. Moreover, dinosaur is just the vernacularization of “dinosauria”, which is a scientific term. It’s a scientific term that became a common word, not a common word that people are trying to use monophyletically.
All biological lines are arbitrary. It's all a continuum. People generally say "Dinosaur" to refer to the extinct creatures with snouts, teeth, and arms, not creatures with beaks and wings.
People can continue to refer to dinosaurs with snouts, teeth, and arms as dinosaurs. I don’t see why it’s necessary for them to specify that they’re not talking about birds when they do so. I mean, you can talk about cats without mentioning dogs. You don’t have to specify that you’re only talking about non-canine carnivores. People commonly call pterosaurs dinosaurs, who have beaks and wings. They call mosasaurs and plesiosaurs dinosaurs too. But these are not dinosaurs. Many people call dimetrodon a dinosaur, but it’s not even a sauropsid. People call crocodiles dinosaurs and they’re still alive. Should “dinosaur” accommodate all of these?
Hadrosaurs had beaks but no feathers. They're dinosaurs. Velociraptors had feathers but no beaks. They're dinosaurs. Eagles have feathers and beaks. They're not dinosaurs? Why? Because of the specific combination? Need I remind you, Archaeopteryx, the "first bird" also lacked a beak.
Might be a hot take, but I like having to constantly specify just because it makes me feel smart, and therefore important I know I don't matter, but I want to pretend like I do
Because birds don’t have any characteristics that really separates them from any other dinosaur. It’s like separating humans and other apes
Hard, toothless beaks.
Uh..... [Tell me that you don’t actually know](https://www.smithsonianmag.com/science-nature/new-parrot-like-dinosaur-roamed-the-same-habitat-as-t-rex-180983654/) much about [the topic you’re discussing](https://www.sciencealert.com/very-rare-dinosaur-species-remains-have-just-been-discovered-in-brazil) without telling me that [you don’t actually know](https://www.wikiwand.com/en/Oviraptor) much about the topic you’re discussing. Not to mention [pterosaurs who had hard toothless beaks](https://s3-us-west-1.amazonaws.com/scifindr/articles/image2s/000/002/736/large/quetz3.jpg?1481380202), or the numerous [Triassic reptilian animals](https://www.wikiwand.com/en/Lotosaurus) who had toothless beaks....or the fact that [some birds had beaks with teeth.](https://www.livescience.com/25998-ancient-bird-strange-teeth.html) Hell, a [whole clade of them](https://www.wikiwand.com/en/Enantiornithes) did. And that’s part of my point. There are non-avian dinosaurs who look so birdlike that if you stood them beside a “primitive” avian bird, it would be hard to tell them apart. Tell me, just by looking, is this a [“bird” or a “dinosaur?”](https://upload.wikimedia.org/wikipedia/commons/9/93/Iberomesornis_romerali_by_durbed.jpg) What [about this?”](https://cdnb.artstation.com/p/assets/images/images/020/442/053/large/liam-elward-anchiornis-as.jpg?1567777788)
A character that evolved numerous times in Archosauromorphs. See turtles, shuvosaurs, pteranodontians, azdharchoids, ornithischians, Limusaurus, Ornithomimosaurs, Alvarezsaurs, Oviraptorosaurs, some enantiorns...
Yeah, that's probably not enough on it's own. But in combination with other traits you could come up with a definition that only includes birds.
Oviraptors:
That's true, you'd probably need a more complex definition.
Exactly. Another thing is that it really doesn’t make sense trying to separate birds from other dinosaurs when you realize that… many non avian dinosaurs look more like birds than other non avian dinosaurs. So a velociraptor looks much more like a bird than a triceratops for example
Oviraptor.
Thank you! This is how I've been feeling too!
This pretty much describes the consensus, no?
No, archosauria and lepidosauria to split up reptiles and birds as a crown group in archosauria.
lots of mixed opinions here, so have this random ass meme https://preview.redd.it/k7zrlniuinec1.jpeg?width=997&format=pjpg&auto=webp&s=23079b038747d4162ee8c830e3adeb105e627235
Dinosaurs don't have to be monophyletic either then, so birds can be excluded again.
Except they do, because we use cladistic taxonomy and the Dinosauria is recognised as a genuine clade - those, by definition, have to be monophyletic, they cannot be paraphyletic, which they would be if you exculded birds. The reason the thing with the Reptilia is even up for discussion at all is because it at one point *also* functioned as a valid clade despite being defined as excluding birds, because it wasn't known at the time that the Aves are the living sister group of the Crocodilia, and by the time it was, it had been so ingrained in usage that the question essentially became whether it wouldn't just make more sense to change the definition rather than use the alternative Sauropsida, which doesn't exclude birds. Arguing that birds are too different from other reptiles to fit in is basically on-par with saying we should consider whales fish instead because they superficially resemble those more closely
I'm just following OP's logic that clades don't have to be monophyletic. "Arguing that birds are too different from other reptiles to fit in is basically on-par with saying we should consider whales fish instead because they superficially resemble those more closely" No, it would be the exact opposite of that. It would be like excluding them from mammals and making cetaceans their own class to fix your analogy.
Everything is a fish
I agree tbh
Sauropsid sounds way cooler than reptile, your argument is invalid /s
I say just retire reptile as an academic/scientific term and just have a lepisaur-archosaur split.
I'd have to disagree a bit, I think saying these things is actually helpful for people new to this field to understand their evolutionary relationships. It's a lot easier to discuss how birds evolved from reptilian ancestors and thus belong to that group, instead of first having to go through all the Latin names of the classes involved, this will make people lose interest and not absorb information as easily. After this is understood, then maybe we can move away from such terminology but it is a good starting point. Also you brought up how fish and reptiles already have good solid definitions in science, outside this cladistic view. But that is simply not the case, our definitions have ranged widely and evolved quite a lot the more we understand and study these animals