# What is--and isn't--a dinosaur? **URL:** \ **Category:** Factual Questions\ **Created:** [January 19, 2019, 4:00am UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027 "2019-01-19T04:00:42Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [January 29, 2019, 8:43pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/61 "2019-01-29T20:43:09Z")
> [@markn\_1](#): > > Does the final statement in this dialogue sound silly? > > A: Look, a red breasted parrot! > B: Oh, that’s a pretty parrot. > A: (sternly) It’s not a parrot. It’s a red breasted parrot. > > Same thing with “we’re lobe finned fishes” but “we’re not fishes”. Normally in English when you modify a noun with an adjective, you get a description of a thing that belongs to a subset of the set described by the noun. And that’s exactly why in the 1700s scientists decided to start using binomial nomenclature instead of common names. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [January 29, 2019, 8:47pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/62 "2019-01-29T20:47:40Z")
Example: A: look! A killer whale! B: wow! What a cool whale! A: actually, killer whales are dolphins. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [January 29, 2019, 9:13pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/63 "2019-01-29T21:13:52Z")
It’s fine to have polyphyletic names, but it can get weird when you mix them with clades in the same conversation. Especially if you _try_ to make it weird. And who wouldn’t? ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [January 29, 2019, 9:49pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/64 "2019-01-29T21:49:31Z")
We should probably just decide that coelacanths aren’t fish. Just say they’re “[marine sarcopterygians](http://tolweb.org/Sarcopterygii/14922)”. _Although coelacanths are fish-like creatures which live in the ocean, they are actually more closely related to land-dwelling vertebrates, including humans, than they are to the true fishes._ Reserve the word “fish” (in reasonably formal or scientific discussions) for the [actinopterygians](http://tolweb.org/Actinopterygii/14923) (which I gather is nearly all of the things we have been calling fishes up to this point). The big loss to the fishes wouldn’t be the coelacanths (and lungfishes); the biggest adjustment would be that we’d have to say that [sharks and so forth (Chondrichthyes) aren’t fishes either](http://tolweb.org/Gnathostomata/14843). _Although sharks and their relatives live in the ocean and share many anatomical features (such as gills) with the true fishes, true fishes are actually more closely related to us than they are to sharks._ After all, we all already get that whales and ichthyosaurs aren’t fishes either. In popular usage, of course, people would still call all sorts of non-fish things “something-fishes” (jellyfish, crayfish, starfish) but we also understand that even though those things live in the water, and are named “something-fish”, they aren’t actually “fish” in the strict sense of the term. (I remember looking in an old _Joy of Cooking_ which had a section on how to prepare and cook “shellfish”, which included lobsters, oysters, and turtles. For culinary purposes I presume that classification actually makes sense. And of course tomatoes are, _botanically_ speaking, fruits, but in culinary terms they’re vegetables.) Moving away from biology, the Sun and the Moon were both originally considered “planets”, and Earth wasn’t. Granted that all such classifications are made up by humans for our own purposes (and are inevitably [somewhat arbitrary](https://en.wikipedia.org/wiki/Brown_dwarf) [at the edges](https://en.wikipedia.org/wiki/Dwarf_planet)), nowadays, we realize that Earth and Mars and Venus properly belong in one category of objects, while the Sun properly belongs in the category of things that includes Sirius and Vega and so on. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [January 29, 2019, 10:15pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/65 "2019-01-29T22:15:59Z")
> [@MEBuckner](#): > > In popular usage, of course, people would still call all sorts of non-fish things “something-fishes” (jellyfish, crayfish, starfish) [And they all love Charlie](https://www.youtube.com/watch?v=lGx4kuteVIA). ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [January 30, 2019, 8:10am UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/66 "2019-01-30T08:10:00Z")
> [@CalMeacham](#): > > **Not a Dinosaur** > Everything in the movie _When Dinosaurs Ruled the Earth_, ironically > > Everything except the T. Rex in _the Land Unknown_ (although the head later showed up as “Spot” on _The Munsters_) > … > > Mkele-Mbembe, whatever they are, more than likely. I don’t care what Disney says. > ) _When Dinosaurs Ruled the Earth_ has a Chasmosaurus,and a Megalosaurus , but yes, most critters in that film and not dinos. I have no idea what Mokele-mbembe was or is, but it is not a hoax. Whatever it was it was considered very rare and is likely extinct now. Last seen right before WW1. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [January 30, 2019, 8:43am UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/67 "2019-01-30T08:43:02Z")
> [@Yllaria](#): > > Had to check. > > The first modern, commercially available toilet paper came on the market in 1857. And although microscopes were available a good bit before then, they probably weren’t considered for use in paleontology until much later. So that checks out. > > The Bone Wars didn’t start until 1877, though, so in theory the bone warriors had toilet paper. I was thinking more in terms of [Linnaeus](https://en.wikipedia.org/wiki/Carl_Linnaeus), who formalized binomial nomenclature and died in 1778. Turns out I was wrong about microscopes: even by a restrictive definition they existed by the 1600s. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [January 30, 2019, 11:37am UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/68 "2019-01-30T11:37:40Z")
> [@Babale](#): > > It does strike me as silly if you intentionally leave out some word, yes. > > Lobe Finned Fish is the name of a […] Band! ---
**Author:** ![Horatio\_Hellpop](https://avatars.discourse-cdn.com/v4/letter/h/e5b9ba/32.png) [@Horatio\_Hellpop](https://boards.straightdope.com/u/Horatio_Hellpop)\ **Post date:** [January 30, 2019, 1:07pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/69 "2019-01-30T13:07:24Z")
> [@Babale](#): > > Example: > A: look! A killer whale! > B: wow! What a cool whale! > A: actually, killer whales are dolphins. Of the ten (major) animal phyla, three are what I’d call “worms.” ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [January 30, 2019, 1:28pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/70 "2019-01-30T13:28:49Z")
> [@Babale](#): > > In other words – can YOU give us a useful definition of the word “fish” that includes all bony, jawless, and cartilage fish, but not any other animal? I don’t know if I can or can’t, since “fish” is a term that is defined by physical characteristics, not cladistics. We don’t consult with scientists before we come up with the words we use in everyday English. However, Wikpedia seems to have a decent definition: “Fish are gill-bearing aquatic craniate animals that lack limbs with digits.” That is how there are animals that end in -fish that are not considered fish. It has nothing to do with cladistics. “Fish” is just a useful group. “Dinosaur” is a bit trickier, since it was coined by scientists (paleontologists, I believe). However, it since gained a definition outside of science, and that definition doesn’t necessarily agree with what animals are in the clade _Dinosauria_. It was coined at a time when scientists used physical characteristics as their primary means of identifying animals, especially for long extinct ones. And it has retained that definition in English. I don’t see that changing, unless a new term is created for the prehistoric creatures. We treat them as a separate group, and we’re not going to put a bunch of adjectives in front of it for everyday speech. We want a word for those creatures from the past that are so different from what we see today. I’m of the opinion that scientific classifications, in order to remain clear, should either use new words, which they have in many cases, or just go back to using the Latin names, which exist for a reason. We came up with scientific naming specifically because common term don’t align with the science, and they never will. AFAIK, all animals we call birds today are members of the clade **Dinosauria**. But calling them dinosaurs is just a marketing technique to try and get people into science. They are only dinosaurs in the same way I do no work when I carry an object across a room. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 30, 2019, 2:18pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/71 "2019-01-30T14:18:58Z")
> [@](#): > > Quoth **Horatio Hellpop** : > > Of the ten (major) animal phyla, three are what I’d call “worms.” I’d actually say eight. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 30, 2019, 2:23pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/72 "2019-01-30T14:23:32Z")
> [@Horatio\_Hellpop](#): > > Of the ten (major) animal phyla, three are what I’d call “worms.” Linnaeus had six major divisions in his original taxonomy: Mammals, Birds, Amphibians, Fish, Insects, and “Worms” (Vermes) for everything else. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [January 30, 2019, 2:24pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/73 "2019-01-30T14:24:43Z")
Well crap, I wanted to see a list of animal phyla and Wikipedia is showing me 35! > **[Phylum | Animals](https://en.wikipedia.org/wiki/Phylum#Animals)** > > Total numbers are estimates; figures from different authors vary wildly, not least because some are based on described species, some on extrapolations to numbers of undescribed species. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million. Things have changed since 10th grade bio. FWIW, that list calls 14 of them “worms” of some sort or another. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 30, 2019, 3:12pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/74 "2019-01-30T15:12:50Z")
On thinking about it, I can only come up with nine major phyla (of which I’d call seven “worms”). Though of course there are many minor phyla, too: 1: Sponges 2: Coelenterates 3: Flatworms 4: Roundworms 5: Segmented worms 6: Arthropods 7: Echinoderms 8: Molluscs 9: Chordates Which one am I missing? The best I can come up with is the tubeworms, but surely, if **Horatio Hellpop** had meant them, he’d have said that he considers four worms, not three? ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [January 30, 2019, 5:44pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/75 "2019-01-30T17:44:52Z")
I learned something today: starfish have bilateral larval forms. I didn’t realize how closely related to us they are. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [January 30, 2019, 6:24pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/76 "2019-01-30T18:24:48Z")
That all makes sense to me – these are some of the oldest complex animals, so it makes sense that they’ve had the most time to evolve. Don’t forget, not only do they have a head start on us chordates, they’ve also been through a heck of a lot more generations than us during any given time span when we’re both around. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [January 30, 2019, 7:10pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/77 "2019-01-30T19:10:26Z")
> [@Pleonast](#): > > I learned something today: starfish have bilateral larval forms. I didn’t realize how closely related to us they are. Well so did I! Down the wiki-hole I go… ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 30, 2019, 7:46pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/78 "2019-01-30T19:46:16Z")
> [@Pleonast](#): > > I learned something today: starfish have bilateral larval forms. I didn’t realize how closely related to us they are. Yes, they are the only other significant Deuterostome phylum besides the Chordates, in which the anus forms before the mouth in the developing embryo. In other major phyla, the mouth forms first. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 30, 2019, 8:12pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/79 "2019-01-30T20:12:14Z")
Or there’s only one digestive orifice, or none at all. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [January 30, 2019, 8:21pm UTC](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027/80 "2019-01-30T20:21:59Z")
> [@Chronos](#): > > Or there’s only one digestive orifice, or none at all. Like [this guy](https://www.nytimes.com/2017/01/30/science/this-prehistoric-human-ancestor-was-all-mouth.html). (Who is not a dinosaur or a fish.) [Previous page](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027.md?page=3) [Next page](https://boards.straightdope.com/t/what-is-and-isnt-a-dinosaur/828027.md?page=5)