Talk:Arthropod

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Contents

[edit] Etymology

Anthro = man

-pod = foot

So Anthropod means man's foot? 205.174.22.26 02:20, 4 May 2007 (UTC)

It is arthro and not anthro. Shyamal 04:33, 4 May 2007 (UTC)

arthro means joint —Preceding unsigned comment added by Adolph172 (talk • contribs) 20:30, 13 January 2008 (UTC)

can't pod also mean leg? —Preceding unsigned comment added by ShadowYams (talk • contribs) 00:34, 21 May 2008 (UTC)

[edit] Taxonomic table

Setting up the table has already caused one fair comment to be raised about what happens to the taxon Uniramia. My visits to various sites on the Net has taught me that the situation about the higher classification of the arthropods is chaotic. Valid arguments could be made for any of many of these schemes. The disturbing thing is that many of these different schemes appear on "dot edu" where they are presented as a professor's gospel to his class.

I've probably already left the impression that, right or wrong, I have a preference to the ITIS scheme, and by extension (since ITIS is focused on North America) looking at the "Species 2000" where applicable. I tend to use these on a "without prejudice" basis that recognizes the difficulties inherent in having bureaucrats control the science. This view treats ITIS as a reference point, and nothing more. If a person B's particular scheme differs from ITIS in a defined way it is 1 generation removed from ITIS. A similar situation applies if C's scheme differs in defined way from ITIS. However, if C defines his scheme with reference to B's then he is 2 generations removed from the reference point. String a few schemes in a row, and you begin to lose perspective on the subject.

Cladists have a stated vision of some day being rid of Linnean ranks altogether. Given the uncertainty that often arises from guessing whether a particular taxon is a class or an order, I can sympathize with that view. But without ranks the cladist's tree sometimes lacks good climbing branches where you can place your feet as you go up.

I think that if we can maintain some consistency in using the primary KPCOFGS rankings, we can have more flexibility with the secondary rankings. There is already some degree of acceptance that in most cases only primary ranks will appear in what was the "Placement" list, and what is now the top part of the tables. That doesn't mean that there can be no exceptions to this rule. (Cf. Wikipedia:Ignore all rules)

So, to get back on topic, higher arthropod classification is confused! But there remains that if we want anything about the subject on Wikipedia, we absolutely need to deal with the confusion. Here then is where I see things as standing between phylum and class in the Arthropoda:

  1. The trilobites (not listed in ITIS) are a phylum with a single class, and that fact appears generally accepted - no problem.
"Generally accepted"? Granted, I'm no expert (I've read a book about trilobytes, is all), but a quick google on "trilobite phylum" got me lots of assertions that trilobites are part of arthropoda. And trying "trilobyte classification" got me a claim that there are eight classes of trilobytes. Vicki Rosenzweig
Yes - were is it generally accepted? I was taught that trilobites were a class of Arthropods and my animal biology text from 1996 confirms this. Has something changed since my freshman year of college? --maveric149
This is a woops -- it should have read subphylum trilobitomorpha with a single class Trilobita. I tried "trilobite classificatio" and it said 8 orders not 8 classes.
  1. Chelicerata seems to be the generally accepted name for that sub-phylum; there may very well have been some reason to distinguish this term from Chelliceriformes in the past, but those reasons seem to be fading.
  2. I have yet to examine issues in the Crustacea, but at least there appears to be general acceptance that is is properly a subphylum.
  3. In text of the article as it has been the Hexapoda has been treated as a class in Uniramia equivalent with the each of the four classes in Myriapoda. Myriapoda was nowhere to be seen; I was ready to throw out Uniramia (not in ITIS) while restoring Myriapoda. Some of the sites that I have seen which treat Uniramia as a subphyllum also show it as containing two Superclasses: Myriapoda and Hexapoda. This may present the most workable solution to this problem because it allows Insecta to remain as a class.
  4. ITIS does not assign a class to the three primitive hexapod orders. We can leave it like that or we can apply a class name from another source. In the latter case some sites have opted for a separate class name for each, some have used Endognatha for all three together, and one has limited Endognatha to the Diplura while assigning the class name Parainsecta to the combined Collembola and Protura. I'm open on this point but will leave it as is in the absence of arguments. Eclecticology, Tuesday, July 16, 2002

The schemes vary, to be sure, but that doesn't mean that the one we choose doesn't matter! The division given on the page was from Brusca & Brusca, about a decade old but still considered a standard reference point. ITIS is quirky on several points, and if this is one of them, I say we should follow something else. To use the extreme example, there is nothing wrong with showing prejudice against their four-kingdom system.

This comes down to a question of what is an authoratative site. http://www.for.gov.bc.ca/hfd/pubs/Docs/Wp/Wp09.pdf uses it but so do several other sites that I called up on google. Tree of life, which is cladistics based and does not use ranks does show hexapoda and myriapoda to have a common source within the arthropoda, but distinct from the rest; it does not use the term Uniramia. The introduction of the super-class seems to be more linked with those sites that accept Uniramia as a subphylum. As I said before, the subphylum/supeclass approach seems like a workable solution.
The mention of Brusca & Brusca raises some interesting questions about doing science on the Internet. Brusca may very well be an important authority who presumably gives reasons for his classification in his book, but that isn't on the net. Buying a copy of his book (1997 edition) on the net would cost me US$60.00 through Barnes & Noble, and I doubt that I could find it on the shelf of a local bookstore. The public library may have it, but it could just as easily have a work on the subject by another author with a totally different point of view. I see Wikipedia as a project about the democratization of knowledge with open codes and data, and one where the sources of data cannot remain in protected fiefdoms. Printed sources that are not easily accessible to the bulk of our readers can have the unfortunate effect of creating knowledge elites.

Can you give something reasonably prominent (i.e. not a prof's page), other than ITIS, that ranks Myriapoda and Hexapoda as subphyla? I've seen various things on arthropods, but can't recall any instances of this, except perhaps in older schemes where the Arthropoda are split into several phyla.

I have seen, in schemes keeping the Hexapoda as a class, the Protura, Collembola, and Diplura made into subclasses. I doubt anyone would go so far as to make them classes, though, so if we want the Insecta as a class we may have to just leave them. The Endognatha used to be use a fair bit, but don't seem to be a natural group and so have lost popularity.

On this point I am quite content to leave the lower hexapods without classes, (even if parainsecta has a certain ring to it).

I'd rather have Hexapoda as a class, which is the way the taxoboxes are set up so far, than have three orders that don't belong to a class. I'm not convinced that those three orders aren't insects - I've seen collemboles, and they look insect enough to me. Why are they classified outside the insects? -phma

Well, as they're the first insects to have diverged from the others, whether they should be included or not is academic, but usually they get separated because of a few key differences. Most notable is that all three have an endognathous jaw structure, whereas true insects have an ectognaths. Also, insects have 11 abdominal segments, while proturans have 12 and springtails have 4-6, and insects have two antennae, whereas the proturans have none.

What a surprise, I'm siding with Josh on this one! I quickly looked through the insect articles, but the only one that I could find with a box set up was the fireflies; that's not a difficult change to make. Sure, Class Hexapoda appears on some old format pages but they need changing anyway. If we accept that collembola "look insect enough" we also have to accept that to some people spiders look insect enough. For a significant majority of people "insect" is a far more familiar term than "hexapod", and there are more different insects than anything else. It would be nice if these primitives had, but I can make do as long as they have order. Eclecticology

If I may, I'd like to reverse my decision on this point. Someone added information to the Collembola page about a study indicating they are not, in fact, closely related to the other Hexapoda. This is, if exciting and ipotentially mportant, still new and I don't think we should remove the Collembola just yet. However. The study porn is sexapoda are closer to the Crustacea than to the Myriapoda. This appears better established, and changes things considerably. A while ago the Uniramia were considered monophyletic and it was unclear whether or not the Myriapoda were. Since then, the monophyly of the Myriapoda became generally accepted (though it still seems mysterious to me) and now the monophyly of the Uniramia is being doubted. As such, the ITIS system of separate subphyla, though less common, is now more generally acceptable, and since I was the one who balked at it at the first place, I'm taking the liberty of restoring it. Please feel free to reverse the change if you have any objections; otherwise I'll clean up the related pages, some of which need cleaning anyways, in the next little while.

Thanks, user:Josh Grosse

-

I'm taking the main classification course on biodiversity for insects for Entomology majors at Texas A&M and the way they break it down is (for class, we probably are only covering what is important to the prof):
Subphylum Trilobitomorpha
Class Trilobita
Subphylum Chelicerata
Class Merostomata
Class Arachnida
Class Pycnogonida
Subphylum Crustacea
Class Cephalocarida
Class Branchopoda
-many more-
Subphylum Atelocerata
Class Diplopoda
Class Chilopoda
Class Symphyla
Class Pauropoda
Class Hexapoda
Just my two cents - Kugamazog

[edit] "Maxillipoda" problem

I've had a chance to look at the crustacea. Four of the five seem well behaved at this level. Only what the article previously showed as "Maxillipoda" gives any problem. ITIS has them as the table temporarily shown with 2 of the 6 as independent sub-classes, Mystocari[di]dae as an order in Ostracoda which is itself treated as a class, Tantulocarida missing entirely, and only Copepoda remaining as a subclass of Maxillopoda. Others choose different combinations to be in or out of Maxillopda. My tendency is to treat all these "sub-classes" as direct classes, and effectively eliminating Maxilopoda since it is left with a single sub-class. I suppose that eventually somebody will come along with more certain material, or lloking more deeply will give us better insights as we move along. Eclecticology, Wednesday, July 17, 2002

[edit] Redundant "tripoblastic"?

Several biology articles contain the phrase "tripoblastic protostomes". Is my understanding correct that here the word "tripoblastic" is redundant, since it describes precisely the Bilateria, to which the protostomes belong? AxelBoldt 19:55 Dec 3, 2002 (UTC)

Entirely so. If memory serves, the phrase was there only as a way to indicate two levels of classification at once.

I disagree. Triploblastic refers to the formation of three germ layers in early embryonic development. Protostomes (vs. deuterostomes) indicates spiral vs. parallel cleavage in the early cell divisions which end becomes the mouth and which the anus. Brunsweiler 02:25, 4 February 2007 (UTC)

[edit] Where to discuss taxonomy?

Question: Where is the proper place to discuss scientic names and taxonomy on the wikipedias of animal names and such. I have more questions, but also some ideas...Please answer on my page! Dan Koehl

[edit] Pararthropoda

Someone had added to this article that the arthropods, tardigrades, and onychophorans make up the taxon Pararthropoda. This name has been applied to the group, but does not seem to be very common, and it is not used in most classification systems - including essentially all that do not recognise the Ecdysozoa. As such, I think mentioning it on that page and treating it in its own article should be more than sufficient. If we try mentioning every group that has been connected with the arthropods, any content we might try adding to the article will be swamped in terminology; we should restrict ourselves to the important ones.

Regarding

[edit] NCBI's high-level arthropod taxonomy.

Just for reference, here is how NCBI's taxonomy site deals with the arthropods.

 PANARTHROPODA (NR)
   ARTHROPODA (P)
     CHELICERATA (SubP)
     MANDIBULATA (NR)
       MYRIAPODA (SubP)
       PANCRUSTACEA (NR)
         CRUSTACEA (SubP)
         HEXAPODA (SupC)
           DIPLURA (O)
           ELLIPLURA (NR)
           INSECTA (C)
   ONYCHOPHORA (P)
   TARDIGRADA (P)

Let's not get confused between taxonomy (the branching structure of the tree, which can hopefully be established empirically) and metataxonomy (the rankings of the nodes of the tree as phyla, classes, and so on). There is no real empirical basis for metataxonomy: it is a matter of tradition and taste. NCBI has a sane policy here: they preserve traditional taxonomic levels wherever possible. For example, when new genetic results motivate a new clade, they typically assign it "No Rank"; an example is the newish Pancrustacea group based on recent evidence that crustaceans and hexapods are allied. The metaclassification of the Crustacea as a subphylum, the hexapods as a superclass, and so on, are all fairly traditional and NCBI tends not to muck with them.

We might consider the following NPOV approach: present a consensus branching order as fact, and then have a separate section devoted to more controversial super- and sub-groupings. For example, we might say:

 ARTHROPODA (P)
   CHELICERATA (SubP)
   MYRIAPODA (SubP)
   CRUSTACEA (SubP)
   HEXAPODA (SupC)

and then later say that some recent researchers favor grouping crustaceans and hexapods into a new group, the Pancrustacea, and so on.

[edit] Arthropod growth confusion

The current paragraph on arthropod cuticles and growth is confusing to someone who is reading this article to learn (e.g., me), as opposed to someone who already knows the subject (e.g., the editors). It makes three apparently different statements about arthropods and their cuticles:

  1. Cuticles are shed in order to grow.
  2. Hardened cuticles prevent further growth.
  3. Cuticles are digested when arthropods need to grow.

I suspect that there is truth in all of these, but there is no flow to this text that suggests what the complete truth might be. (Are these aspects of different arthropods? Are they each part of a different growth cycle in all arthropods? Are there other possibilities?) The wording suggests at least two editors for this text with entirely different writing styles that did not attempt to connect the two sections. Could someone knowledgeable about this topic fix that paragraph? Thanks. — Jeff Q 03:09, 10 Feb 2005 (UTC)


[edit] Other confusion

A minor note, but the opening paragraph states that "over eighty percent extant (living today) animal species are arthropods" and the following paragraph contradicts that with "75% of all animals on Earth are arthropods". That second paragraph could be removed altogether, however I am not sure which is correct >80% or 75%.

Those two numbers aren't even related. One deals with numbers of species, and the other deals with numbers of individuals. Species vary enormously as to how many individuals there are of each species. Asking "which is correct" is comparing apples and oranges. MrRedact 19:44, 11 August 2007 (UTC)

[edit] Taxonomy again: sources needed

The list of Crustacean classes in the taxobox is missing some groups of animals: in particular, non-cirripedian thecostracans and pentastomids. Why is this? Whose classification are we using? There's no reference in the article, and the classification doesn't follow ITIS, or SN2000, or Martin & Davis, all of which have a class Maxillopoda containing these missing groups.

The article says only:

Here we have followed a "splitting" taxonomy, containing only generally accepted groups and assigning them higher ranks

It's not a problem to have different classifications in different articles as long as we have a good justification, ideally a reference to a reasonably authoritative source. (And for the moment I'll update the taxonomy to include the missing groups). Gdr 22:02, 3 January 2006 (UTC)

[edit] Classification Rewiev

10 feb. 2007


On most points, this agrees with what we have. Most of the stuff it adds are not common and don't add much to the article (things like "subdomain Opisthokonta") or are generally considered obsolete (things like class Trilobitoidea). The main exceptions are the use of Maxillopoda and Uniramia; as discussed above, things can go either way on these.

Whose classification is this? Gdr 10:45, 10 March 2006 (UTC)

[edit] Why is breathing by trachea difficult?

It is not clear why breathing by trachea raises a difficulty for creatures with an exoskeleton. Dan Gluck 19:48, 26 August 2006 (UTC)

[edit] Confused, legs/segment?

Quote: "The common ancestral arthropod, though, apparently happened to be one who had evolved not just chitinous mouthparts like other segmented worms, but also a chitinous structure all over its body; with all arthropods, the segments have become distinct (at least in larvae), each covered with one or more plate, and with legs, or limbs, one pair per segment."

Am I just reading it wrong if I think it sais that all arthropods are restricted to one pair of legs / segment? If not, diplopoda are defined by them having two pairs of legs on each segment excluding head, rear and the four segments following the head. Fjejsing 06:08, 18 September 2006 (UTC)

  • Rats. Just found out that diplopoda has merged two segments, hence the dual pairs of legs. Nm my previous post, sorry for the lack of research, move to delete. Fjejsing 06:15, 18 September 2006 (UTC)

[edit] For arachnophobes

Considering that arachnophobia is one of the most common of visceral phobias, and that even many perfectly sane mature adults instantly and (admittedly) illogically freak at the sight of spiders, is it possible that we could limit arachnid pictures to articles that deal with arachnids, and use less adrenaline-producing photographs for the top picture and templates, etc., dealing with arthropods in general? How about insects and crustaceans? In fact, that seems more logically diverse, as the former tend to be more common on dry land and the latter tend to be more aquatic, presenting a diverse picture of arthropods. Also, for situations that use only one picture, is it possible to prefer insect photos, as they are the most common? My point is, spider photographs should be of last relevance since they are considered the most scary. I want to keep it all encyclopedic and such, but I'm figuring that maybe there can be some leeway in this area? - Gilgamesh 22:10, 29 November 2006 (UTC)

Do many people even freak at the sight of a photo of a spider? Well, maybe that's a good reason to get them used to seeing them, isn't it? Isn't acceptance a good start on the path to comprehension? Seriously, there are plenty of places where you are likely to see the picture of a spider, be it in advertisement, on TV, in real life... etc. Also, I think that a lot of people are also scared of insects. Do you think that it would be better to have a centipede, mite, or cockroach? Probably most people who will recoil at the sight of a spider will do the same for a lot of other arthropods. And I don't think that it's a good idea to put a pretty butterfly just because people like them more. Wikipedia isn't about doing things the way the general public likes; we're not trying to attract more users by making user-friendly articles. Also, I think that insects are the most obvious of arthropods; therefore why put a picture of one, since it would have less educational value?
Also, consider pages about human anatomy. Do articles like labium or vulva not put an explicit picture at the top because some people are going to dislike it? Nope. And I can't think that more people in this wide world are offended by a picture of a spider than one of genital parts. What's more, I'm pretty sure that more people visit the anatomy pages than this one. However, the explicit photos prevail, since wikipedia is not censored.
Well, you got my opinion, and I dare say that it is likely to be the same one as most of the editors of this article. IronChris | (talk) 23:34, 29 November 2006 (UTC)
Well, I honestly don't think it's really about censorship of offensive pictures, but merely being considerate of a truly adrenaline-pumping phobia that affects a very large part of the population. It's like being considerate of people who are allergic to peanuts. It's very common, and it's very sensible, and it is not due to any offensiveness at all. Anyway, I replaced the top photograph with another image very commonly associated with arthropods, and that's the honey bee. Mindful that this would put too insect pictures on the page, I replaced the insect picture further down the page with a picture of one of the most common arachnids in the world, the dust mite. This way, the article has a photograph of two very familiar very common animals, one insect, one arachnid, and the article remains wholly encyclopedic without censorship. Besides, the fear of all bugs you mention is not actually arachnophobia, but the wider (and less common) insectophobia (which usually includes all arthropods). There are still many people who jump out of their skin at spiders but not at honeybees, and even not at certain other arachnids such as ticks and mites. - Gilgamesh 07:31, 30 November 2006 (UTC)
No, I'm sorry: this is taking things too far. Spiders are an important group of arthropods, and we can't shy away from mentioning and illustrating them just because some people have a phobia. If their problem is that bad, then they should either a) get over it (not the most sympathetic solution, I admit, but perhaps the best in the long run), b) not read an article which is dedicated to a decidedly spider-rich group, or c) turn the pictures off on their browser. Wikipedia is not censored, and pictures of spiders are not to be avoided where they are relevant. I also think that many more people find ticks and mites (particularly in close-up) unpleasant, so even by your own logic, the changes don't make sense. I always try to avoid putting the most obvious sub-group in the infobox where possible, to avoid giving people the impression that arthropods are basically just insects (for example). My apologies to all arachnophobes (especially those who find a few coloured pixels objectionable in addition to living moving animals), but I think the previous solution really was better. Perhaps if a consensus for change can be established, then we can make it, but until then, the old solution's fine. --Stemonitis 08:36, 30 November 2006 (UTC)
I just thought I'd take a second to voice my agreement with Stemonitis, that the picture choice should not be based on what will be easier on people, but rather what will help the most people learn. Hopefully in the future, we will get the article long enough to include a picture from every major group, but for the time being, the less expected ones are the most useful. Cerealkiller13 16:17, 30 November 2006 (UTC)
Well, you both have very good and correct points. In particular I think you have a wise point that an article's main photograph should do more to educate rather than to regurgitate what people already know. But I feel the need to reiterate...must it be a spider? There are all sorts of obscure arthropods that could make excellent top pictures. There's centipedes, millipedes, horseshoe crabs, coconut crabs, Japanese spider crabs (which aren't actually spiders), dragonflies, mantises, fleas, trilobites (extinct but nevertheless an excellent example), barnacles, scorpions, scarabs, the list goes on. This is one of the biggest classifications of life on earth. So I'm saying here, does it have to be specifically the animal with eight legs, eight eyes, binocular vision, pedipalps, silk glands, flesh-liquefying venom and a need to consume all nourishment in liquid form? If we need a picture that gives a nuances image of what an arthropod can be, I suggest either (1) the image should be a collage (including an arachnid—I still suggest non-spider XD), or (2) the image should represent an animal with features that a great deal many arthropods have in common while still demonstrating how varied the shape can be. - Gilgamesh 05:23, 1 December 2006 (UTC)
A collage would be a possibility, provided each of the sub-images remains big enough to be meaningful. Animal uses that approach, for instance (with a hardly representative sample of four vertebrates and one cnidarian!). A big picture divided into four quadrants, one for each of the major extant groups would be fine. So, we'd have one hexapod, one crustacean, one myriapod and one chelicerate. For the chelicerate, a horseshoe crab is hardly typical, and other groups are either too long-legged for a small picture (harvestman, pycnogonids, Solifugae?), some are particularly small, making comparison between the four quadrants more difficult (ticks and mites), and then there are groups like scorpions (I can't find any scorpion picture of a similar quality to the current tarantula) and of course spiders. So, I think that in the absence of a really good scorpion picture, there would probably still be a spider involved. But in principal, I'd be perfectly happy with a collage, and if an alternative high-quality picture can be found, it needn't be a spider. In that case, an image of a spider would, however, probably be needed later in the article; we can't just ignore the most familiar chelicerates. --Stemonitis 12:09, 1 December 2006 (UTC)

I think a collage is a great idea. Maybe I'll try making one myself when I get the time. However a collage leaving out spiders is like a collage on the animal page leaving out birds; you just can't leave out the second most representative group of arthropods. Of course, a scorpion picture might do (though, is a scorpion less scary than a spider??), or perhaps a mite micrograph, something like this: Image:House Dust Mite.jpg, Image:Rust Mite, Aceria anthocoptes.jpg or Image:Tick male (aka).jpg (again, any mite blown up that size is, by most people's standards, rather hideous).

So perhaps we could include a spider picture in the collage; I mean, it would be a compromise, wouldn't it? The spider picture would be a quarter of its present size, and wouldn't be the main focus, since it would be sharing that space with three other arthropods. IronChris | (talk) 21:02, 1 December 2006 (UTC)

How about a spider with long legs and a tiny body? - Gilgamesh 22:54, 1 December 2006 (UTC)

Anything with long legs and a tiny body tends not to look good in photographs, because all one sees are a bunch of legs, which could belong to all sorts of different animals. This problem is even worse for smaller pictures. As an iconic chelicerate picture, I think the tarantula is about the best we can do. --Stemonitis 10:24, 2 December 2006 (UTC)
I agree, the only pictures as good as that one were showed... other tarantulas! There aren't many spider pictures that look good small, as far as I could see. IronChris | (talk) 18:51, 2 December 2006 (UTC)
That was actually my intent... Darn. X3 - Gilgamesh 06:58, 9 December 2006 (UTC)
Can anyone tell me some of the following things for my studies? It would be much appreciated. What genus of arthropods has remained mostly unchanged for millions of years? What is the largest genus of Arthropods? What class of arthropods arrived on land before the others? What order evolved a unique excretory system to adapt to living in a dry environment? What is the smallest Arthropod Genus? Thanks.:: -- GigantoPithicus
Oldest surviving genus: Triops, 220 million years
First class to colonize the land: Millipedes, most likely; Silurian geological period
Smallest genus: There are many arthropod genera containing only one species; examples include Amphionides and Birgus.
Hope this helps!--Crustaceanguy 15:40, 15 March 2007 (UTC)

[edit] Evolution

The Evolution section could really use some more sources, especially recent ones. Its primary source (from 1989) basically repeats the Articulata theory, but most articles say that the newer Ecdysozoa theory has wider support. Eluchil404 13:36, 23 January 2007 (UTC)

The Ecdysozoa article has this reference [1] which may be helpful. Shyamal 03:40, 24 January 2007 (UTC)
Thanks. I'll take a look and try to come up with something cogent to add to the article. Eluchil404 16:02, 26 January 2007 (UTC)

[edit] Possible classification of Arthropoda

The following is a possible way to classify arthropods. The ranks here are based on how I had been taught; in reality, of course, they are controversial. It is the grouping that matters.

PHYLUM ARTHROPODA (ARTHROPODS)

By Crustaceanguy 16:37, 9 March 2007 (UTC)


Yes, there are many ways to classify arthropods, and the article does discuss some variants, albeit not in very much detail (but then it would make for a very dull article if it went into too much detail). The one used in the taxobox is a fairly commonplace scheme, based on the one at ITIS (and elsewhere). Your classification is interesting, but I doubt that it is widely accepted. Speaking as a carcinologist, any classification in which Insecta is at a higher rank than Crustacea seems very poor, considering that insects may be nested within Crustacea. --Stemonitis 16:49, 9 March 2007 (UTC)

[edit] Future elimination of the phylum Arthropoda

Could the phylum Arthropoda be eliminated in the future (that is, split into several different phyla) due to its polyphyly?--Crustaceanguy 14:56, 15 March 2007 (UTC)

I'm not aware of any work that has found Arthropoda to be polyphyletic (or even paraphyletic for that matter), so, no, I don't think it's likely. --Stemonitis 15:44, 15 March 2007 (UTC)

[edit] Recent Classification purpose

--79.8.164.201 09:57, 12 June 2007 (UTC)

Um, while that's pretty and everything, I'm not sure why you've put it here. Any classification with epiclasses and granclasses is clearly not going to be the commonly-accepted classification that Wikipedia would use. I've also just noticed that it uses "Hexapoda" at two different ranks and for two different taxa — where does this scheme come from? --Stemonitis 10:00, 12 June 2007 (UTC)
Subphylum Hexapoda was the ancient taxa where insects, elliplurs and diplurs were put together; after inects (and similars) were extrapolated and classified as Mandibulata, Subphylum Hexapoda remained only with diplura and elliplura, but insects (and other primitive generes) still belong to a "hexapoda" group, so the term hexapoda still names two split groups. Granclass is an artificium to group pauropoda, diplopoda and symphyla, because they are ususally grouped as: Chilopoda + Progoneata or Chilopoda + Symphyla + Dignatha.
 79.8.164.201 10:25, 12 June 2007 (UTC)

[edit] Taxonomic authority for "Arthropoda"

Does anyone actually have a reference for the supposed introduction of this term by Latreille 1829? All the Internet sources I have seen appear to be reproducing the attribution without checking. The only piece of writing by Latreille in 1829 that I know of is his essay in the new edition of Cuvier's Regne Animal, and in the English translation of this only the name "Condylopa" is mentioned. I suspect that the authority for the name may actually be von Siebold 1845. Myopic Bookworm 16:52, 3 September 2007 (UTC)


[edit] water-dwelling, not 'marine'

I made a minor change under the "Classification of arthropods" section, for the following: "Crustaceans are primarily marine (a notable exception being woodlice)". I changed the term "marine" to "water-dwelling", because the word marine refers to the ocean, not all water. there are both freshwater as well as marine crustaceans...such as freshwater shrimp. I made the change, but then it got changed back. I'm going to make it water-dwelling again, and I'm just putting this down in the hopes that the person who is changing it back will see this post. 66.32.166.209 (talk) 22:54, 20 January 2008 (UTC)

They are primarily marine with some notable freshwater and brackish water species, maybe add those details rather than change to water-dwelling would be better. --Amaltheus (talk) 00:48, 21 January 2008 (UTC)

sounds fine to me, although I don't trust myself to add those kind of details without doing a fair amount of research. I would want to go into a bit of detail about those different species. ---66.32.166.209 (talk) 06:39, 21 January 2008 (UTC)

It's not an article about these species, that would be in the crustaceans articles. But that article may have information and links to research on freshwater and brackish water crustaceans such as the brine shrimp. --Amaltheus (talk) 06:43, 21 January 2008 (UTC)
The technical term for "water-dwelling" is aquatic. Myopic Bookworm (talk) 12:37, 21 January 2008 (UTC)

ok, aquatic it is, then. 66.32.146.72 (talk) 21:51, 23 January 2008 (UTC)

Yes, aquatic, thanks Myopic. Please include a freshwater example in the list. I think there are only three primarily marine crustaceans as examples. --Amaltheus (talk) 03:19, 24 January 2008 (UTC)

ok, I added shrimp and crayfish, as shrimp include freshwater species while crayfish are exclusively freshwater. any objections? 66.32.178.222 (talk) 19:26, 25 January 2008 (UTC)

[edit] Trilobite in taxobox

A week ago, User:FISHMAN1 removed the tarantula image [2], and later, User:Bob the Wikipedian added the trilobite image [3]. The image is quite fine, and is probably worth including in this article. However, I believe that an extinct member of a group with over 1 000 000 extant species is not very representative. If you would like to share an opinion of this image, please tell me.--Crustaceanguy (talk) 14:06, 20 April 2008 (UTC)

I would be ok with a Trilobite if it looked less plastic. I think a living arthropod is definitely more easy for people to relate to. A non-insect is preferable here and I thought the tarantula was fine. Shyamal (talk) 14:48, 20 April 2008 (UTC)
I simply noticed it didn't have an image and added one. I'll put a different one there in a sec. Bob the Wikipedian, the Tree of Life WikiDragon (talk) 04:42, 21 April 2008 (UTC)
I'm not sure why the tarantula was removed, but I've replaced the trilobite with a sea spider. Bob the Wikipedian, the Tree of Life WikiDragon (talk) 05:01, 21 April 2008 (UTC)
The sea spider was a little too low in resolution, have reinstated the tarantula. Shyamal (talk) 05:40, 21 April 2008 (UTC)
Fine by me. I didn't repost the tarantula, since I wasn't sure what the reason was for its removal. Bob the Wikipedian, the Tree of Life WikiDragon (talk) 19:37, 21 April 2008 (UTC)

they are so cute —Preceding unsigned comment added by 75.183.180.72 (talk) 15:31, 27 April 2008 (UTC)

Agreed. Tarantulas are rather cute. It puzzles me how girls can be so grossed out by them. Bob the Wikipedian, the Tree of Life WikiDragon (talk) 18:39, 27 April 2008 (UTC)

[edit] Category:Animals

Why not put this page in Category:Animals since Arthropod is a main article for Category:Arthropods, a direct subcategory of Category:Animals?--Crustaceanguy (talk) 12:16, 3 May 2008 (UTC)