Talk:Arthropod/Archive 1

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Etymology[edit]

Anthro = man

-pod = foot

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

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

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

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

Ill get started on an Anthropod article (I searched, and there actually isn't one). Then we can compare the two. Geno-Supremo (talk) 10:05, 15 May 2009 (UTC)[reply]

I really have no expertise on this subject whatsoever, but doesn't 'Anthropod' refer to a totally different species? Correct me if I'm wrong, but it seems to me that there is a common confusion of Arthropod and Anthropod[1] (at least on Google). In that case it would be (as it was for me) highly irritating to refer one page to the other. Or am I missing something? Sebowsky —Preceding unsigned comment added by 92.241.56.102 (talk) 21:34, 26 July 2009 (UTC)[reply]

Taxonomic table[edit]

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

"Maxillipoda" problem[edit]

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

Redundant "tripoblastic"?[edit]

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)[reply]
But if all animals from nematodes to the more derived forms are protostomes (except the deuterostomes, which came from a protostome ancestor) then isn't it redundant? By necessity all protostomes would be triploblastic as their common ancestor had already developed 3 germ layers. Not a big deal, but it would make more sense to call them coelomate protostomes.ExoditeTyr (talk) 19:45, 12 December 2009 (UTC)[reply]

Where to discuss taxonomy?[edit]

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

Pararthropoda[edit]

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

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

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.


From my understanding Hexapoda is a Sub-Phylum and Insecta a Super-Class; I'm not too sure, but can anyone confirm? ExoditeTyr (talk) 19:50, 12 December 2009 (UTC)[reply]

Arthropod growth confusion[edit]

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)


Other confusion[edit]

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)[reply]

Taxonomy again: sources needed[edit]

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)[reply]

Classification Rewiev[edit]

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)[reply]

Why is breathing by trachea difficult?[edit]

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

When increasing creature size it would be more difficult given the surface area/volume relationship. Couldn't see anything related to breathing difficulties in the article, so this is this just an old post? ExoditeTyr (talk) 20:14, 12 December 2009 (UTC)[reply]

Confused, legs/segment?[edit]

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)[reply]

  • 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)[reply]

For arachnophobes[edit]

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)[reply]

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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]

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)[reply]

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

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)[reply]
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)[reply]
That was actually my intent... Darn. X3 - Gilgamesh 06:58, 9 December 2006 (UTC)[reply]
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)[reply]

Evolution[edit]

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)[reply]

The Ecdysozoa article has this reference [1] which may be helpful. Shyamal 03:40, 24 January 2007 (UTC)[reply]
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)[reply]

It's actually far more complex than that. The recent studies are still undecided on the issue, and it has proven so hard to tackle that by now very arcane statistical methods are being used (and still don't resolve it). Whether Ecdysozoa is recovered monophyletic or not depends more on methodology than on dataset, which it should definitely not do (see end of section 9 here). doi:10.1078/0944-2006-00131 is a bit old, but despite more data and more esoteric analyses (that yield apparently stronger phylogenies but also depend on more variables, and for few of these the underlying assumptions have ever been tested) we have made little progress from the situation 7 years ago: try as you may, you cannot recover Articulata in the traditional sense. But you can recover Ecdysozoa monophyly as well as non-monophyly in state-of-the-art scientific studies, depending of what you want to recover. Most people these days want to recover Ecdysozoa, so they include Drosophila, some crustacean and perhaps 1-2 other "ecdysozoans" and "recover" a monophyletic Ecdysozoa.

I have changed the intro accordingly to reflect that

  • Articulata are for most scientists a discredited theory
  • Lophotrochozoa are a strongly supported group - essentially all analyses recover it and its internal structure clearly. One can cite e.g. this as recent source. Compare with the first paper linked above - Ecdysozoa weaken with increased taxon sampling (particular if you include these insidious and extremely undersampled nematodes) while Lophotrochozoa if anything get better supported.
  • Ecdysozoa are a group with equivocal support - some analyses have even found it paraphyletic with Lophotrochozoa or Deuterostomia. But a naive assumption of their monophyly (see e.g. the link above) does not conflict with the results of many analyses either (e.g. if you would assume "Articulata" to be monophyletic, and sample your data accordingly, your results would often look weird), at least if nematodes are kept outside the analysis. Its internal structure is does not resolve well either - it looks as if the right basal protostomian could tear it apart.
  • basal relationships of Metazoa are not consistently recoverable yet, except that Deuterostomia and possibly Protostomia are the major subdivision(s).
  • "animals that molt" is misleading, as ecdysis may be plesiomorphic or paraphyletic for Protostomia (if these are monophyletic).
  • for all we know by now, it assuming articulation is plesiomorphic for at least some Protostomia (fide doi:10.1046/j.1463-6409.2003.00122.x, but rather the other way around, with Lophotrochozoa in "Ecdysozoa" - see Lophotrochozoa study above).

As an aside, Nature/Science/PNAS tend to receive most publicity, but have a mediocre standard of quality by now. Wikipedia cannot trust their authority alone; they had been burned by major scientific fraud far too often to consider their current standards of peer review still sufficient. I'd really add more and more thorough references from journals with less hype factor and more rigorous quality control. Dunn et al. (2008) has been cited a lot of course, but few authors take care to review it. Those that do are those that need to be cited here. Dysmorodrepanis (talk) 20:46, 11 March 2010 (UTC)[reply]

Dysmorodrepanis, I hadn't realise that there were doubts about Ecdysozoa, but one should expect surprises like this - as you say, many analyses conclude that they expect to conclude. --Philcha (talk) 22:39, 11 March 2010 (UTC)[reply]
Since Arthropod I've been working on articles on lophotrochozoan phyla, and it seems that Lophotrochozoa are less clear than they seemed - see Brachiopod and Bryozoan, especially the 2 citations in Brachiopod that brachiopods' nearest relatives may be nemertines, which were a surprise to their authors. --Philcha (talk) 22:39, 11 March 2010 (UTC)[reply]
Are there any analyses that criticise the quality of Nature/Science/PNAS? --Philcha (talk) 22:39, 11 March 2010 (UTC)[reply]

Possible classification of Arthropoda[edit]

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)[reply]


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)[reply]

Future elimination of the phylum Arthropoda[edit]

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)[reply]

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)[reply]

Recent Classification purpose[edit]

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

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)[reply]
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)[reply]

Taxonomic authority for "Arthropoda"[edit]

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)[reply]


water-dwelling, not 'marine'[edit]

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)[reply]

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)[reply]

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)[reply]

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)[reply]
The technical term for "water-dwelling" is aquatic. Myopic Bookworm (talk) 12:37, 21 January 2008 (UTC)[reply]

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

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)[reply]

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)[reply]

Trilobite in taxobox[edit]

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)[reply]

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)[reply]
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)[reply]
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)[reply]
The sea spider was a little too low in resolution, have reinstated the tarantula. Shyamal (talk) 05:40, 21 April 2008 (UTC)[reply]
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)[reply]

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

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)[reply]

Category:Animals[edit]

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)[reply]

Possible structure[edit]

Tricky, as a lot of the sub-topics inter-connect. Here goes:

  • Description
    • Definition
      Invertebrates with jointed limbs
      The (?) only other instances of jointed limbs are tetrapods, which are vertebrates.
    • Exoskeleton
    • Development
      Primarily direct, w/o larval stage (they have so-called larvae, but not radically different as in lophotrochozoa or basal deuterostomes)
      Hexapods avoid moulting by metamorphosis. What about spiders & other chelicerates?
    • Coelom
    • Circulatory system
    • Respiratory systems
    • Senses
    • Communication
    • Lifestyles - incl 1st fliers
    • Size range (mentioned in intro)
  • Evolution
    • Fossil record
      Ediacaran & Cambrian; colonization of land; flight; Carboniferous-Permian giants, dep on high O2 concentration
    • Phylogeny
      • Protostomes
      • "articulata" and "ecdysozoan" hypotheses
      • lobopods, etc.
  • Classification
    • Note Cambrian "unclassifieds".
    • Tagmosis & arthropod head problem.
    • Current well-defined sub-phyla.

-- Philcha (talk) 09:44, 25 September 2008 (UTC)[reply]

Please review[edit]

I've had a go at getting Arthropod into good shape for Wikipedia Version 0.7. I doubt whether there's time to get it up to A-class or GA, but I'd hope B-class would be easy enough. Please comment.

Then we can consider the V 0.7 offer of free copyediting. -- Philcha (talk) 13:10, 29 September 2008 (UTC)[reply]

Hi, the content seems pretty good; I don't think it's wanting in any respect. I think the largest scope for improvement in the article would be if you found a proofreader who hasn't been involved in it so far, to make the content flow better. Martin (Smith609 – Talk) 17:14, 5 October 2008 (UTC)[reply]
Where do you think it gets bumpy? -- Philcha (talk) 17:40, 5 October 2008 (UTC)[reply]
  • Could do with some coverage of locomotion modes.
  • Could do with coverage of some other modes of reproduction - esp. the various forms of "parthenogenesis".

Shyamal (talk) 14:57, 26 October 2008 (UTC)[reply]

Hi, Shyamal. I agree about parthenogenesis, although it will have to be be brief and limited to strictly "virgin birth".
I'm less sure about locomotion, as a mere list of "walking, swimming, jumping, flying, parachuting and burrowing" would not be very interesting, but going any further would expand that part of the content out of proportion, especially where flight is concerend. Do you have some specific ideas about how make it brief but interesting, with good refs? -- Philcha (talk) 14:00, 27 October 2008 (UTC)[reply]
Well, there does not seem to be any single work that has found a clear binding thread but I am sure there is a lot of interest from the point of view of evolutionary themes as well as the technological inspiration. I do not have access to academic databases but here are some areas to think of (trying to keep out insect-heavy areas)
  • Aquatic movement
    • swimming
    • swimmerets
    • jet propulsion
  • water surface
    • entspannungschwimmen
    • sailing
  • Legged locomotion (doi:10.1038/043223b0 The Locomotion of Arthropods)
    • Onychophora - hydrostatic + muscular leg movement
    • joints -
    • millipedes
    • forwards-walking macrurans, or sideways-walking brachyurans (Arthropod Struct Dev. 2008 Mar;37(2):95-108.)
    • paleontological evidence - trackways - and the evolution of terrestriality
    • distributed foot (Robert Full - TED talks - havent found refs on this but maybe this has something Full, R. J., Blickhan, R., and Ting, L. H.1991. Leg design in hexapedal runners. Journal of Experimental Biology158:369-390. )
  • Saltation
    • Collembola
  • flight with no wings
    • phoresy (mites)
    • Spider balooning

A very slipshod list for inspiration

Shyamal (talk) 15:13, 27 October 2008 (UTC)[reply]

That's exactly what I'm worried about, Shyamal. Expanded to normal prose, including competing theories, and with refs, all that's enough for a separate article - compare it with Talk:Arthropod#Possible_structure above. However such an article would be too much of a heterogeneous catalogue, and I think all that content is better dealt with under the relevant taxa, e.g. Spider already mentions that spiders have no extensor muscles and rely on hydraulic pressure to extend their appendages. There's also an article on Insect flight, and IIRC one theory is that flight evloved from sailing.
A few points caught my attention. Jet propulsion in arthropods? What's "entspannungschwimmen"? Re onychophorans, Arthropod currently takes the view that it's about Euarthropoda rather than Panarthropoda, in line with both common usage and the view of most textbooks. Oh god, I suppose I'll have to add Euarthropoda and Panarthropoda to my rapidly lengthening to-do list. -- Philcha (talk) 15:39, 27 October 2008 (UTC)[reply]
A quick overview may still not hurt. Seems like jet propulsion was in cephalapods and was seen again only in the anisopteran larvae. I must have got the spelling of the other wrong, but it is seen in some water surface insects where they use saliva to cause movement by surface tension of water.
  • It looks like the size reduction trend with lowered oxygen concentration is missing (was perhaps there in the past) Shyamal (talk) 01:30, 28 October 2008 (UTC)[reply]

Taxobox[edit]

Does the taxobox need to list taxa below sub-phylum level? At present it extends so far down the page that it restricts that space available for illustrations. -- Philcha (talk) 11:18, 25 September 2008 (UTC)[reply]

Cuticle[edit]

This set of edits is factually correct but messes up the structure of the relevant paragraph and section. I hoped that the 2nd para said enough about chitin but if not, that's where a brief description of chitin should go. I'm undoing the edits and invting the editor concerned to have a look and discuss. -- Philcha (talk) 17:09, 3 December 2008 (UTC)[reply]

Spider[edit]

Do you have to have a giant picture of a spider on this page? I've just jumped back from the screen and now im sweating —Preceding unsigned comment added by 82.28.168.34 (talk) 03:50, 4 July 2009 (UTC)[reply]

thank you so much[edit]

This was a fantastic article to read, I felt it struck a wonderful balance between the amount of detail and referring the reader to other sections of Wikipedia to read in more detail. I really enjoyed this, so thanks.

I have no idea if this is allowed, I have never been moved to say "thank you" before. I am sure someone will delete it promptly if I am out of line. But this is why I read Wikipedia.

Gratefully,

FQ1513 (talk) 06:38, 28 July 2009 (UTC)[reply]

This is the kind of response that makes an editor's work worthwhile. Thanks! --Philcha (talk) 17:46, 3 September 2009 (UTC)[reply]

Alexey's edits (16:45, 16 October 2009)[edit]

Hi, Alexey, thanks for the additional content that extends the description of the "Fossil range" section and related items. Can you please clear up the formatting of these items, especially the dates, to follow the formatting in the rest of this article - see template {{ma}}, and in date ranges place the earlier date first. Thanks, --Philcha (talk) 09:16, 24 October 2009 (UTC)[reply]

A bivalve arthropod fossil was found in the Anabarites trisulcatus–Protohertzina anabarica Zone of China. Last zircon 206Pb/238U ages for Meishucun Bed 5 (Anabarites-Protohertzina Zone):
540 Ma in the "Fossil range" is the average arithmetical. Сhinese Anabarites–Protohertzina Zone correlated with upper part of the Siberian Anabarites trisulcatus Zone. Zircon age for border Anabarites trisulcatus Zone – Purella antiqua Zone its 543.9 ± 0.24 Ma. I did not mention about Ediacaran naraoiid Keretsa borei (age 555.3 ± 0.3 Ma) since it is not described and the information on it not yet published. Feel free to edit my additional content. Aleksey (Alnagov (talk) 11:38, 25 October 2009 (UTC))[reply]
Perhaps the best way to illustrate formatting the dates is to show an example. --Philcha (talk) 12:56, 25 October 2009 (UTC)[reply]
Re date of Parvancorina and Spriggina, where did you get 555 million years ago. The sources cited at present are not specific (Glaesner could not be, because radiometric was in its infancy when Glaessner was working), so I used a general "Late Ediacaran" range. --Philcha (talk) 12:56, 25 October 2009 (UTC)[reply]
Parvancorina fossils known from the Lamtsa – Verkhovka (age 558 ± 1 in lowest Verkhovka Fm.) – Zimnegory (age 555.3 ± 0.3 from lowest Zimnegory Fm.) – Yorga formations (it is time range ~560 to >550 Mya) in Arkhangelsk Oblast, Russia and from Flinders Range in Australia.
Spriggina fossils known from Flinders Range. Flinders Range locality correlated with Verkhovka and Zimnegory formations. Other sprigginiids is Marywadea from Flinders Range, Cyanorus from the Verkhovka, Zimnegory and Yorga formations. Aleksey (Alnagov (talk) 18:09, 30 October 2009 (UTC))[reply]
If you provide bibliographical details for the citations, it to be great to make the times of the critters more specific. --Philcha (talk) 19:31, 30 October 2009 (UTC)[reply]
Correlations and dates with references: User:Alnagov/Sandbox/Time range for Dickinsonia and Tribrachidium
Or in one paper: http://www.charnia.org.uk/saturday_school_2007.htm#gehling Aleksey (Alnagov (talk) 21:23, 30 October 2009 (UTC))[reply]

And others[edit]

"include the insects, arachnids, crustaceans, and others." Other whats? Unfree (talk) 03:10, 1 November 2009 (UTC)[reply]

Arthropod taxa - incl some fossil taxa different from those alive now. --Philcha (talk) 07:13, 1 November 2009 (UTC)[reply]
Myriapoda would likely be the largest (and is extant), but probably best to not list it as it is not well known to the lay reader under that name (and I can't think of any more common terms). ExoditeTyr (talk) 20:03, 12 December 2009 (UTC)[reply]

in fact there are no external signs of segmentation in mites?[edit]

No?

http://en.wikipedia.org/wiki/File:Yellow_mite_%28Tydeidae%29,_Lorryia_formosa.jpg

http://en.wikipedia.org/wiki/File:Flat_mite,_Brevipalpus_phoenicis.jpg

Although this appears to be a sort of layering, not true segmentation, it's worth comparing:

http://en.wikipedia.org/wiki/File:Rust_Mite,_Aceria_anthocoptes.jpg

I think this claim needs to be clarified, perhaps with more information from the provided source. —Preceding unsigned comment added by 128.170.62.95 (talk) 21:00, 1 December 2009 (UTC)[reply]

  1. ^ http://en.wiktionary.org/wiki/anthropod

Referencing method[edit]

If you wish to change the referencing method on a last article that although passed in the last 18 months and is well maintaining, you should discuss the change first. I've revert the latest and then the others on bloc. I see some objections:

  • The use of {{r}} provides at least a minor convenience, which does not outweigh the replacing of the universally understood <ref>.
  • Very useful tools are based on the <ref>, including refTools and User:AnomieBOT. These are so useful widely used that use of something like {{r}} must be tested comprehensively for compatibility with such tools before it can be used for real, i.e, {{r}} must have one or more sub-pages that collectively show that all variations are correct and none are omitted. All these tests would have to re-done before any no version of {{r}} be used for real - this is called regression testing.
  • I remember a discussing at the Village Pump a few months ago about "defencing over-referencing", i.e. an increasing to add refs in case one adds a {{verify}} or other tag later, possibly after the book in question is not available. IIRC the consensus was that "defencing over-referencing" was unavoidable, and one preferred an option in Mediawiki to suppress the output of <ref>. {{r}} should not be used until it should be approved by the Mediawiki development team. --Philcha (talk) 07:35, 30 January 2010 (UTC)[reply]
  • I think that Philcha's claims are incorrect (although I cannot fully comprehend the English) so I will restore the {{r|... list of references, with its considerable benefits to article clarity.
  • The use of {{r|... does not preclude the use of standard tools. It is completely compatible with a mixed environment, that's why the changes were made over 10ish edits, it was a mixed environment for 90% of the process. Thus future editors are completely free to continue using their preferred tools and methodologies. Considerable further usage information and experience has been accumulated by Wotnow. Regards. Chienlit (talk) 10:05, 30 January 2010 (UTC)[reply]


  • refTools and other citation formatters output <ref> tags. Do you intend to watch every article that uses {{r}} and convert <ref> tags every time some one adds a ref using one of these citation formatters?
  • Have you or any one else tested thoroughly that User:AnomieBOT and other bots can use the output of {{r}} as reliably as they use <ref>? Until the impact all the relevant bots has been tested, it is not safe to use {{r}}. Note that the burden of proof weighs on who propose the change, not on whose who find the current method satisfacory.
  • A mix of {{r}} and <ref> will confuse inexperienced editors, and these have enough to learn already.
  • I've just looked at your contributions. It seems this is the first article on which on which you have large scale changes using {{r}}. If you want a test-bed, you should use one on which you done all lot of the work on the contest yourself.
  • I've reverted your changes again. If you make this into a revert war, I'll escalate the issue vigorously and immediately. --Philcha (talk) 11:09, 30 January 2010 (UTC)[reply]
Hello Philcha, in order to maintain clarity I have interleaved my responses to each of your/Philcha's points below. Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]
  • refTools and other citation formatters output <ref> tags. Do you intend to watch every article that uses {{r}} and convert <ref> tags every time some one adds a ref using one of these citation formatters? Philcha
  • Response: Refute. It is no business of yours whether I check my watchlist or not, although a look at my history will show that I do because of the vandalism edits. Of course I intend to watch every article that I edit. But, more to the point, {{r}} is a bona fide wiki function that does not need to be nursed by me, it does need to be nursed by anyone, it works. And because it was designed to work in a mixed environment any editor can continue to use their preferred citation tool. (refTools is fine.) Although {{r}} doesn't need me, a glance at other articles such as Archaeopteryx and History of the Earth will show that I have provided ongoing maintenance. In summary, Philcha's 'argument' appears to be no more than an accusatory question based on irrelevant and unknowable (by him) future scenarios. Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]
  • Have you or any one else tested thoroughly that User:AnomieBOT and other bots can use the output of {{r}} as reliably as they use <ref>? Until the impact all the relevant bots has been tested, it is not safe to use {{r}}. Note that the burden of proof weighs on who propose the change, not on whose who find the current method satisfacory. Philcha
  • Response: Refute. {{r}} is a bona fide wiki function, there is no 'burden of proof' required. It does not need to be proven or nursed by me, it does need to be proven or nursed by anyone, it already works, it was proven before it was released. And because it works successfully in a mixed environment any editor, any bot, any citation tool, can continue to work without impact. They can either work with it or in parralel. Yes it works with User:AnomieBOT. Philcha is neither the arbiter of which tools and techniques can be used, nor the gatekeeper who ensures that 'only the current method' / status quo are acceptable. Once again I suggest that you study User:Wotnow's extensive page, which will also lead you to the original creator and tester. Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]
*A mix of {{r}} and <ref> will confuse inexperienced editors, and these have enough to learn already.Philcha
  • Response: Refute. You have no idea what will or will not confuse the thousands of inexperienced editors, I believe this to be wild, rhetorical scaremongering, and professing knowledge about the skills of other editors that no-one can have. The {{r}} function is designed to work in a seamless mixed environment thus it is irrelevant to any editor who prefers to work in the old way, they still can. My actual, verifiable experience is that other editors pickup the skill very quickly, judging by the occasions when my errors have been fixed by others faster than I could edit and resave. Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]
  • I've just looked at your contributions. It seems this is the first article on which on which you have large scale changes using {{r}}. If you want a test-bed, you should use one on which you done all lot of the work on the contest yourself. Philcha
  • Response: Refute. Blatant rubbish! I have monitored, used and discussed the reflist technique extensively since 14 October 2009, as a review of my talk page and history will disclose. This was highlighted when I pointed out the extensive {{r}} articles, list of articles and threads at User:Wotnow. Although there are too may pages to list here, the technique works perfectly on Adolphe Clement, Archaeopteryx, Ernest Shackleton, History of the Earth etc. Secondly, your statement that I should work on an article where "You done all lot of the work on the contest yourself" displays a worrying attitude. I do not own any articles (not even the 3 on DYK today), and neither do you, this is Wiki. Chienlit (talk) 13:27, 30 January 2010 (UTC) Please follow the link to User:Wotnow.[reply]
  • I've reverted your changes again. If you make this into a revert war, I'll escalate the issue vigorously and immediately. --Philcha (talk) 11:09, 30 January 2010 (UTC)[reply]
  • Response: Refute. I don't think that threatening me with a revert war is a particularly constructive or appropriate way to proceed, but I guess it matches the tenor of the outrageous claims about my lack of expertise and {{r}}'s lack of testing. I am not one of Wiki's politicians or bureaucrats, and so have zero experience of 'vigorous and immediate escalation' and 'revert wars', but I do know that you are free to do whatever you feel you must. I guess it will be interesting and educational :-) Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]
I am sure that this will be settled amicably, but so far, in my judgement you (Philcha) have not raised a single material objection, just unfounded claims (I don't like it, others will be confused, chienlit has no experience, chienlit has never used it before, {{r}} is untested, {{r}} is unproven, chienlit will not support it in the future,). Please assure me that you have read User:Wotnow before you revert for a third time. Unfortunately the extensive nature of the changes, embedded throughout the article, means that they will almost undoubtedly conflict with any other bona fide changes, causing complex re-editing which I am concerned is beyond me, ergo I will need to reinstate them until the 'vigorous and immediate escalation' is in the hands of admins or arbitrators, or the issue is resolved. Regards Chienlit (talk) 13:27, 30 January 2010 (UTC)[reply]

Protection[edit]

I have protected this page for one week. I trust that all editors concerned will use that time to discuss the relative merits of both sides of the current dispute, and ideally seek outside opinions. --Stemonitis (talk) 14:20, 30 January 2010 (UTC)[reply]

Thank you Stemontis. I know that the protection does not imply any opinion either way, but thanks for the temporary respite. Did something automatically alert you to level 2 edit war? regards Chienlit (talk) 15:29, 30 January 2010 (UTC)[reply]

(Note: a link to this discussion was posted to Wikipedia talk:Good article nominations.) Putting aside any benefits posed by whichever reference style an article may or may not use, there was no consensus for a major reference style overhaul in this article. Contentious edits should not be made (especially to a high quality article that is being regularly maintained) without a discussion. Cheinlit, your edits, although well intentioned I'm sure, were obviously not agreed upon. If you wish to educate other users as to the benefits of using {{ref}}, I suggest that before you make any changes to the article, that you first post to articles' talk pages, describing how this little-known style can help streamline references, increase readability, etc. etc. You make some good points above which should have been brought up three-or-so reverts ago. Otherwise, those who have maintained high quality articles, sometimes for months before your involvement, may see it as an affront on their hard work, and simply revert, which is what happened here. Discussion first, changes only after there has been an agreement between editors. Otherwise, you will experience more headbutting and unproductive page lock-downs. María (habla conmigo) 17:40, 30 January 2010 (UTC)[reply]

Wise words María, thank you.

I will try to summarise a few benefits here, although it may take several edits. You rightly conjectured that the effort was well intentioned but you slightly erred with my history, some editors morph from urls and other names (for aesthetic reasons :) but do not desert their old watch-lists. My long-standing involvement with Arthropods however is minimal in comparison to Philcha. I didn't seek prior approval because I didn't (and still don't) think that I had to, surely nothing in Wiki is owned, surely no editors have proprietorial rights, surely consensus is everything. Obviously communal approval is the ideal and I assumed that such approval would be forthcoming (normally tacit, occasionally stated) when the benefits were clearly manifest in the article itself, which is my experience in other respected articles.

It is hard to envisage having had this discussion in advance of editing, endless talking about confusing theoretical outcomes of a technical discussion. At least it is for me and many others who struggle with impenetrable technical tomes. If I had been a bystander I would have voted/voiced against. As the proposer I probably wouldn't have the discussion, I wouldn't be bothered, I prefer to do something other than argue about how many angels stand on the head of a pin. I would edit elsewhere or put up the retired notice, yet another amiable well intentioned editor butted out by hard heads who are used to being hauled into Wikiquette.

Benefits[edit]

  • The main benefit of the reference template is that it clears the body of the text of all the citations, thus making it read like a simulacrum of the article, as fluently readable and searchable as the article itself, readable by any editor who is interested in the text/content. Reading/searching an edit text (I don't yet know the right technical terms, but maybe by the end of the debate) peppered with circa 100 citations is difficult in the extreme, and although many editors will doubtless say that 'you get used to it', with templates 'you don't have to'.
  • The most bloody awful task is searching for a main citation that is embedded in para 27, but is linked from a dozen other locations, eg <ref name="Chienlit"/> peppered from paras 1-100 acting like red herrings. With templates its easy, the citation is in the references section, clearly formatted and filed in alphabetic order.
  • An editor wishing to fix a citation does not even have to 'Edit' and review the entire page, just click 'Edit' on the the ==References== section of the main article, and go straight to the citations, in alphabetic order.
  • The mixed environment is very powerful and forgiving:
  • the main text can accommodate a random mixture of <ref name="Chienlit"/> and {{r|Chienlit}} without any consequence. It simply works.
  • the main text can still accommodate <ref name="Chienlit">[http...] citations
  • the main text can still accommodate <ref>[http...] citations
  • Once experienced {{r|Chienlit}} cannot be confusing because the references are in alphabetic sequence in the References section, even easier and more intuitive that the 'in order of appearance' in the article. So much more intuitive than finding the {{reflist|2}} completely empty.
  • The sorted list of refs provides 'no hiding place' for cock-ups that are often embedded in the main text. In my experience of clearing/cleaning major established articles I always discover tiny bits that had been buried in the tsunami of inline cites, (yes arthropod included), so I know that other users find it equally confusing. Templates are naturally visually cleaner.
  • The template allows a single citation to be shared by multiple refs, each with their own superscript page numbers. Thus highlighting that this book has been ref'd 7 times a,b,c,d,e,f,g, but without losing detail. I don't think in-line cites can do this, the full cite data is repeated for every different page number. eg Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, Ruppert, etc before it was templated. (Unfortunately I was interrupted before the final stage of consolidating, so it still contains 4 Rupperts, but it could/will be just one.)
  • Nobody has to change their modus operandi in any way, the work has been done. Everybody can now carry on as before, which is what has happened in all the other articles that I have touched since Oct 2009.
  • With {{r|Chienlit}} refs can use just the author name, and page number if appropriate. Horrors like <ref name="VollrathSelden2007BehaviorInEvolutionOfSpiders"> can become {{r|Vollrath}}.

In summary I don't think I need to 'sell' this function, simply studying the edit text for a few minutes makes the benefits obvious, especially if you go back to the pre{{r... version.

Regards Chienlit (talk) 20:19, 30 January 2010 (UTC)[reply]

(move this to correct place after ec --Philcha (talk) 22:55, 30 January 2010 (UTC))[reply]

Chienlit's claim that "The most bloody awful task is searching for a main citation that is embedded in para 27, but is linked from a dozen other locations ..." is false - in the article's User:Cacycle/wikEd or even the "Edit->Find" of some browsers you can idenfity the main ref instantly, because this contains a /. --Philcha (talk) 22:49, 30 January 2010 (UTC)[reply]
I don't know this is an limitation of {{r}} of of the way Chienlit's has implemented it here, but he has rolled into one ref 10 page/ranges under ref [6], cited at 35 locations in the page. In my my last change and the last version before Chienlit's changes, there was a ref for each page/ranges, so that each ref to Ruppert, Fox and Barnes (2004) identified the passage of the book that supported the corresponding passage of the text. Chienlit's method fails to comply with Wikipedia:CITE#Identifying_parts_of_a_source and the examples at Wikipedia:CITESHORT#Shortened_footnotes, and probably fails to comply with WP:V as Chienlit's method makes it impossible to identify what part of the book supports which statement in the articles - in other words, this article was a GA but has I think it now falls short of the standard,as a result Chienlit's changes. And Chienlit says "Unfortunately I was interrupted before the final stage of consolidating, so it still contains 4 Rupperts, but it could/will be just one"! --Philcha (talk) 22:49, 30 January 2010 (UTC)[reply]
Chienlit's claim that "Horrors like <ref name="VollrathSelden2007BehaviorInEvolutionOfSpiders"> can become {{r|Vollrath}}" shows ignorance of scientific literature. Build it up one part at a time:
  • "Vollrath" (or whoever) is likely to publish several works on the same or related topics that are cited in the WP article.
  • And "VollrathSelden" (Vollrath and Selden) are likely to publish several works on the same or related topics ..., so I add the year because I often find further works by Vollrath and Selden.
  • "VollrathSelden2007BehaviorInEvolutionOfSpiders", which Chienlit regard as a "horror", was a response to a situation that occurred a few times in paleontology, where the team publish papers about 2 or 3 fossils in the same bed in the same years. It can also be a helpful minder when the team publishes in consecutive years. --Philcha (talk) 22:49, 30 January 2010 (UTC)[reply]
  • <ref> is easily identified by User:Cacycle/wikEd's colour coding. Is there any colours that easy identified {{r}}. If not, {{r}} is harder to read. --Philcha (talk) 22:49, 30 January 2010 (UTC)[reply]
The bottomline is that <ref> is recommended and explained in various guidelines, and is supported by some useful tools and bots. As far as I can see, {{r}} is not supported by these guidelines, tools and bots. {{r}} looks like a solution in search of a requirement. --Philcha (talk) 22:49, 30 January 2010 (UTC)[reply]
  • <edit conflict> I have never heard of {{r}} and agree with you that reference names are easy to find merely by using the browser's "find" feature in the browser edit window. I also agree the <ref> is the commonly accepted method in Wikipedia articles, and it is built into Wikipedia's many ref tools. In any event, any changes in the existing citation style needs to be discussed first with the article's established editors, of which you are one, and I am some what of another, and consensus reached. Having edited this article in the past, I had no problem understanding the citation style or finding references in the edit window. The existing citation style, which has been stable for over a year and a half at least, should be returned to the article. It is not for one editor who does not have a history with the article, to make a unilateral decision against concensus with established editors of the article. —mattisse (Talk) 23:13, 30 January 2010 (UTC)[reply]

Win at all costs? Or resolve logically?[edit]

Hi folks. What a remarkable argument. The first and foremost question that comes to mind is whether good faith actually exists, and the parties actually want to resolve it, or just win at all costs.

Chienlit is right about my user page. It covers much, even most of the issues raised here, either on the page, or collectively, via the page and links to other pages. For example, if you go to the original discussion link prior to the straw poll in . September. July 2009, you'll see, surprise surprise, many of the issues covered there.

I apologise if the page layout is not optimum at present, it evolved as I worked through the various issues, and the structure reflects that. I have been pondering on how to restructure it for over a week now. Nevertheless, it covers a fair bit of the stuff argued over here, in relation to List-defined references, which was originally notified as active on 21 September 2009.

I'm sure that you will all check for yourselves, since I'm sure you are all acting in good faith, and none of you are wanting to create false, straw-man, or psueudo-arguments, which is chiefly the domain of politicians (for whom winning is all) and pseudo-scientists (for whom ideological belief is all), as eloquently described by writers such as Martin Gardner, Michael Shermer, and Robert Park.

Now I'm not surprised that some people hadn't heard of list-defined references. I hadn't, and nor had GyroMagician or Kudpung, but we thrashed out some of the issues in very good faith, in a series of dialogues that would put to shame what some Wikipedians do in various discussions. Niether of us wanted to 'win'. We wanted to figure out the issues, and learn from each other in the process, which I'm sure is what people here want to do.

Also, I'm sure that Philcha, having made the good-faith effort to check it out, will realise that things like the 10 page/ranges, cited at 35 locations, rolled into one reference, is human error, and not a limitation of the referencing system. Philcha will of course know that by now, because Philcha will of course have checked out the evidence by now, because Philcha no more wants to knowingly create false arguments than anyone else.

So in the end, it will come down to good faith. Good faith is not always easy to see at first, but as time goes on, it always becomes self-evident, as does bad-faith. Regards, Wotnow (talk) 09:21, 1 February 2010 (UTC)[reply]

Addendum. You'll see on checking my user page, a couple of things. First, the list-defined referencing method is self-evidently not difficult to understand. It is impossible to say, grasp the Harvard referencing style yet claim not to understnd the list-defined referencing style: they are similar in their functions, except the list-defined method is unequivocally simpler, as GyroMagician and I found in our exercise. And of course if you read the relevant dialogues on that - for which I've provided links, that becomes self evident, if you haven't already thought it through yourselves. And no, that's not a dig at people. It's very evident that GyroMagician and I were thinking through this stuff as we went.

Lest it be thought that I am an ideologue pushing some utopian panacea (I'm not. I don't do ideology, period), it is self-evident upon reading the page, that I deliberately both found and generated examples showing that list-defined references do not need to replace any method, nor cause anyone to make wholesale changes to their style. You will see for example, that I pay homage not to templates of any sort, but the utility of the reference, and I explicitly acknowledge differing methods of achieving this, just as I explicitly acknowledge say, the utility of the Harvard referencing templates for getting embedded references out of the article, just as the list-defined reference method does. And I deliberately list a Featured Article that has free-hand, embedded referencing using ye olde <ref> tags, as well as other examples. It is impossible to read through my user page and not see these things. No folks, all I've tried to do is bring it together in one easy to find place. You will of course all have seen this, having read through the material as you seek, and demonstrate the desire to seek, a good faith outcome, as opposed to say, escalating the argument as a smoke-screen for another agenda. Regards. Wotnow (talk) 11:02, 1 February 2010 (UTC)[reply]

Would that it were Wotnow, would that it were. My final opinion is, as already stated below, to agree with Mattisse and the MOS, otherwise I would feel obliged to waste yet more hours countering yet more 'enigmatic' statements about me and my capabilities, but I assume that even a snarling slavering attack dog is acting in good faith because of a perceived need to ingratiate itself with its master/keeper/betters. So best to just walk away and forget it, and hope that the leash doesn't break. Hey ho.
For the record I am not 'ignorant' of scientific publishing methodology, quite the opposite, so do not appreciate a self-confessed 'arm chair' contributor claiming such. The ref label is internal to its wiki page, it has no scientific bearing. Secondly, a few moments of checking will show that all of the 35ish page references to Rupp are clearly defined in both the article and the reference. Page numbering detail is not lost, it is improved, it is available while reading the article.
I was about to bow out of this with a Yorkshire truism, There's none so blind as them that will not see but experience of life and knowledge of history shows that there's none so blind as them that 'ave an agenda. Chienlit (talk) 12:48, 1 February 2010 (UTC)[reply]
Wotnow's heading "Win at all costs?" is a good descriptive of Chienlit's attempt to impose the use of {{r}} amd Wotnow's supporting of this attempt to impose {{r}}. That is unacceptable, see various guidelines including: Wikipedia:Manual_of_Style#Stability_of_articles; Wikipedia:Cite#Inline_citations, which supports <ref> and says nothing about {{r}}.
I also see no point in using {{r}} for some citations and <ref> for other, as I see no point in learning to use a 2nd technique when the one I know works for each type of citation, has good documentation, and is the standard in all revelant guidelines.
<ref> is well supported by a range of good citation tools, some of which I use dozens of times per article (e.g refTools) and some of which are useful bots (e.g. AnomieBot) - see also Wikipedia:Citing_sources#Citation_templates_and_tools. I see no benefit in use {{r}}, as {{r}} can at best perform as well and has the risk of failing to support some of the established tools. The only to minise the risk would be for {{r}} to minimise the risk would be for it's sponsors to research all the relevant tools and publish thorough tests of {{r}} with each operation within each tool - a large job.
Cheinlit has broken the correspondence between the references' pages numbers/ranges and the statements they support. This is required by Wikipedia:WIAFA 2c and in practice is required in GA reviews. Arthropod was passed as a GA in November 10, 2008, i.e. by the current version of WP:WIAGA, and has been maintained since. As a result of Cheinlit's "human error", the article is no long of GA. The only efficient and reliable remedy is revert all Cheinlit's changes to Arthropod, so that it restores correspondence between the references' pages numbers/ranges and the statements they support. --Philcha (talk) 13:56, 1 February 2010 (UTC)[reply]

Misunderstanding regarding the references[edit]

This article should maintain the reference style provided by the editor who achieved the GA status for the article. See Talk:Arthropod/GA1. Changes in the referencing style should not be made unless there is consensus with the editors who have worked on this page.

The Arbitration Committee has ruled that editors should not change an article from one guideline-defined style to another without a substantial reason unrelated to mere choice of style, and that revert-warring over optional styles is unacceptable.[1] Where there is disagreement over which style to use in an article, defer to the style used by the first major contributor.

  1. ^ Wikipedia:Requests_for_arbitration/Jguk#Principles, Wikipedia:Requests_for_arbitration/jguk_2#Principles, and Wikipedia:Requests_for_arbitration/Sortan#Principles

The previous referencing style should be returned to this article. It is not permissible to edit war over this issue. Please also see Editing policy - Be cautious with major changes: discuss. Regards, —mattisse (Talk) 22:42, 30 January 2010 (UTC)[reply]

I agree with Mattisse, the MOS should be adhered to. I was right when I said this exercise would be educational :) Chienlit (talk) 12:19, 31 January 2010 (UTC)[reply]

Moving forward[edit]

Well folks, I guess the first question to answer is whether or not you want to continue utilising List-defined references. If the answer to that is yes, then my suggestion is that the easiest way to move forward is to replace the "r" templates with <ref name=/> templates.

I have no opinion either way myself, other than to note that if there are issues with the use of the "r" templates, and the same outcome can be achieved with the <ref name=/> templates, why not implement the latter and just keep moving forwards. Issues regarding the "r" template will sort themsevles out one way or another, and in the meantime everyone knows how to use the "ref" templates. And if the issue for some is decluttering the main text of the full reference, that can be achieved with "ref" templates anyway. So what if they're a little longer. They're not always that much longer, and you still get the full reference (which is longer) out of the article text if that's your aim.

I would also suggest that even if you decide to opt for list-defined references, if some find it easier to place the reference in the body of the article, good on them. It won't do any harm. The article will read the same and work the same if some refs are grouped at the bottom and some embedded in the text. Anyway, good luck with this, whichever way you decide to go.

You may at least take heart that as Stephen Jay Gould often pointed out (the panda's thumb always springs easiest to mind, but there's others) as does Daniel C. Dennett (and others of course), evolution itself doesn't always provide optimal outcomes. It provides working solutions. And hey, it produced us. Regards Wotnow (talk) 05:36, 7 February 2010 (UTC)[reply]

IMO List-defined references is only of the techniques one can use, and the same article can use a variety. IMO refs where list-defined references cases more work than they save include refs that have no page number/range (e.g. most academic journal articles) and those that cite one page number/range. Wikipedia_talk:Featured_article_candidates#RfC_on_additional_wording_about_citation_templates and Wikipedia_talk:Featured_article_candidates/Citation_templates#Discussion_citation_templates are also relevant (as least some of the time :-D ) --Philcha (talk) 08:26, 7 February 2010 (UTC)[reply]
Thankyou. Much appreciated feedback. These are indeed some of the things to consider. Regards Wotnow (talk) 10:44, 7 February 2010 (UTC)[reply]
Resolved
 – Wotnow (talk) 23:21, 10 February 2010 (UTC)[reply]

I have only just noticed (after closer inspection following recent vandalism) that the page was in fact restored to the version that preceded the {{r}} template. That obviously negates my suggestion about replacing the {{r}} templates! At time I became aware of the above discussions on 1 February, the page had been frozen (on 30 January) with the {{r}} templates intact. What I didn't notice at time of my comments in this section, was that just prior to the page being unprotected on 6 February, it was restored to the last version before the dispute. And that version used embedded <ref> templates.

So my comment regarding the {{r}} templates is redundant. As for the question of list-defined references, well everyone now knows what they are if needed or desired. And I for one have learned that they are not exclusively dependant on {{r}} templates (which I didn't know prior to the above discussions), and I've picked up a few other tricks besides. I would eventually have learned these things, but this got me there a lot quicker, for which I am grateful. So in this article, there are no issues to resolve regarding {{r}} or LDR. You can just keep moving forward. Regards Wotnow (talk) 23:21, 10 February 2010 (UTC)[reply]

Swiss army knifes[edit]

I'm not sure where to mention this, but the reappearing likening of arthropods to a specific brand of pocket knife, "swiss army knife," seems completely unnecessary. If the correlation need be made, might I suggest just using "multi-function pocket knife" rather than a specific brand. It really is frivolous, and this should be edited out. Thanks. —Preceding unsigned comment added by Ross perot69 (talk • contribs) 21:49, 13 February 2010 (UTC)[reply]

The phrase is used from a source (a textbook) in the main text. It now has a general as a brand-specific - for example "Hoover" can refer to any brand of electric carpet / floor clear. It's not frivolous, it's more memorable for readers. --Philcha (talk) 23:21, 13 February 2010 (UTC)[reply]

Study finds surprising new branches on arthropod family tree - Duke University[edit]

I am not a specialist, so I cannot judge if it is worth including or not, but the following scientific news seems to me to be very relevant for the "Evolution" section. Could the main editors consider it?:

Study finds surprising new branches on arthropod family tree - Duke University

--Pmronchi (talk) 12:44, 15 February 2010 (UTC)[reply]

The link is a news item, and we'll need to see when we see the scientific in Nature. Even then we'd have to phrase as e.g. "X suggested that ..." as it's a new idea that hasn't been checked by other scientists. However, we be very interested, thanks for the heads up. --Philcha (talk) 15:44, 15 February 2010 (UTC)[reply]
Here's the citation:
  • Jerome C. Regier, Jeffrey W. Shultz, Andreas Zwick, April Hussey, Bernard Ball, Regina Wetzer, Joel W. Martin & Clifford W. Cunningham (2010). "Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences". Nature. doi:10.1038/nature08742.{{cite journal}}: CS1 maint: multiple names: authors list (link)
--Stemonitis (talk) 14:57, 17 February 2010 (UTC)[reply]
Thanks - I think, as I'll need some time. Also I'll see well combined studies agree this - combined studies that include fossil taxa such as trilobites have been spoilers in the last. I'll tried to check it oever the weekend. --16:42, 17 February 2010 (UTC)

Classification of arthropods needs updating[edit]

The Classification of arthropods section needs to be updated (especially the tree diagram), per this paper. I know what you're thinking: we have to revise arthropod classification on a weekly basis every time a new paper comes out that contradicts the last one. This study is different, however, as it is the first truly comprehensive molecular study across the phylum. Rather than 4 or 5 genes, they sampled 62 genes per species (across 75 species). The results are quite robust, as you can see in the paper. Kaldari (talk) 23:11, 15 April 2010 (UTC)[reply]

Please see discussion here. Kaldari (talk) 18:48, 16 April 2010 (UTC)[reply]

New estimation of number of arthropod species[edit]

A summary in ScienceNOW here outlines a new study in The American Naturalist here estimating the global number of arthropod species to be between 2.0 and 7.4 million (with a median of 3.7 million). They also estimate the number of tropical arthropod species: a median of 2.5 million with a 90% confidence interval of 1.1 to 5.4 million. How does the soundness of these estimates compare with that of other studies of this subject? Emw (talk) 14:39, 22 May 2010 (UTC)[reply]

With arthropods it's difficult to count even the "described species". IMO the Chicago estimate of global number of arthropod species has such large margins for error that it really means "we don't know". --Philcha (talk) 20:37, 22 May 2010 (UTC)[reply]
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