Talk:Chelicerata/Archive 1

Archive 1

Eurypterids

I added a the class Eurypterida to the article, but it isn't alinged with the other classes. How can I fix this? Giant Blue Anteater 16:39, 21 October 2006 (UTC)

Compound eyes?

The article says some chelicerates have compund eyes, but it doesn't provide examples. Eyes says compound eyes are found in insects and some bivalve molluscs and annelids with no mention of chelicerates. Which is correct? Ace of Sevens (talk) 23:56, 25 October 2009 (UTC)

See Eyes#Apposition_eyes - the horseshoe crab Limulus is a chelicerate and has compound eyes. --Philcha (talk) 06:47, 26 October 2009 (UTC)

Cambrian Origin

The Burgess Shale animal 'Sanctacaris' was probably the first Chelicerate, extending the range to the Cambrian. See Steven Jay Gould's Wonderful Life, p. 187.

There is room for uncertainty - see Chelicerata#Fossil_record. --Philcha (talk) 05:08, 14 January 2010 (UTC)

I no longer maintain this article

I no longer maintain the article. Some person(s) have inserted {{R}} templates. This template is bad for readers, as it clutters the page; and it is likely to be detached from the text. I am not doing the work to repair this, it should be done by the person(s) resonsipible for damaging the artcile. --Philcha (talk) 04:50, 10 July 2010 (UTC)

I tried to update the taxobox for this article to the newer {{Automatic taxobox}} system, but was reverted by the person who "no longer maintains the article". Perhaps there is an ownership issue here? Kaldari (talk) 21:52, 28 July 2011 (UTC)

Taxobox photograph

I believe a sea spider is not a good example of a chelicerate. Many scientists are unsure whether they should be classified in this superclass. An arachnid(spider, scorpion, etc.)or horseshoe crab would be better, I suppose.--Crustaceanguy 21:45, 24 January 2007 (UTC)

Why doesn't someone mention their close affinity to ( and probable descendancy from) trilobites?-- Marcraymond (talk) 04:41, 18 May 2012 (UTC) 12:33, 18 May 2012 — Preceding unsigned comment added by Marcraymond (talk • contribs)

GA Review

This review is transcluded from Talk:Chelicerata/GA1. The edit link for this section can be used to add comments to the review.

Intro

The introduction is too long, compared to good articles. The intro is supposed to summarize the body, without giving major detail. When it comes to taxonomic group pages, I support the KISS principle, and would move just about everything to a "General physical description" section. The first paragraph should stay, the rest should be moved into the body (either together or piecewise). StevePrutz (talk) 14:39, 30 October 2008 (UTC)

What do you think of the new version at User:Philcha/Sandbox/Chelicerata#Lead_.28v_1.29? That's down from 571 words and 3804 chars (incl spaces) to 449 words and 2908 chars (incl spaces). All the cuts are in the zoological description, as the other paras are short. The items about chelicerae, tagmosis and the generally very centralized nervous system are chelicerate special features, as is their near-universal inability to ingest solid food. Minimizing water loss is important - my textbook says failure to do so is why crustaceans are much less successful on land. By invertebrate standards predatory chelicerates' courtship rituals are very elaborate. Some also provide near-mammalian levels of child care. -- Philcha (talk) 17:11, 30 October 2008 (UTC)

The version you proposed at User:Philcha/Sandbox/Chelicerata is certainly shorter! However I don't think it satisfies WP:LEAD, for example "The lead should be able to stand alone as a concise overview of the article. It should establish context, explain why the subject is interesting or notable, and summarize the most important points—including any notable controversies that may exist." More specific comments:

• There is no doubt that the earliest Chelicerata were marine. That's important from an evolutionary point of view in its own right, and also raises the question of how many marine Chelicerates there are now. I don't know of any other sub-phylum that originated in the sea but is now so predominantly air-breathing.
• I think more needs to be said about chelicerae. The mere fact that they are the only appendages that appear before the mouth is significant only to the few readers familiar with the arthropod head problem.
• The diversification of chelicerate feeding strategies is a significant factor in their success.
• The centralization of the CNS is not consistent enough to be a defining feature, but is still remarkabe among arthropods.
• The near-mammalian level of parental care in some spiders and scorpions is AFAIK far beyond anything found in non-chelicerate invertebrates.
• I think the phylogeny should be included, under "summarize the most important points—including any notable controversies that may exist."

I've produced a version 2 at User:Philcha/Sandbox/Chelicerata#Lead_.28v_2.29. -- Philcha (talk) 21:39, 30 October 2008 (UTC)

BTW you should register the fact that you're reviewing this at WP:GAN -- Philcha (talk) 21:42, 30 October 2008 (UTC)

Steve, I'm puzzled that you started with the lead - most GA reviews I've seen leave the lead until last, after the main content is agreed.

I also think your last proposal still omits too much. A major problem we both face here is lack of precedents, as most zoology articles at phylum or sub-phylum level are unimpressive. There's one GA for a phylum, a handful of B-class and most of the rest are start-class. A summary of articles on phyla & sub-phyla whose names I can remember off the top:

• Insect and Trilobite are both A-class but Insect failed a GA review in Feb 2008 and I suspect still would, and I don't think Trilobite would make GA at present. Crustacea was promoted to GA in May 2006 but in its present state would fail a GA reassessment.
• Echinoderm, Gastropod B-class but would have no chance of GA in their present state.
• Sponge B-class, I'm working on it now.
• Cnidaria , Annelid, Brachiopod, Nemertea , Lancelet (redir from Cephalochrodate), Vertebrate start-class
• Hemichordata, Tunicate stub-class
• Cephalopod, Bivalve unassessed

Editors generally avoid high-level taxa because these require a larger amount of research and citations per N words of content than lower-level taxa.

Since most high-level taxa include a wide range of lower-level taxa with diverse morphologies, physiologies, and life-styles, there's a lot to say, e.g. what features are common to the taxon and which vary widely among lower-level taxa - and then the range of variation needs to be explained if possilbe.

I suggest it would be a good idea to review the rest of Chelicerate and then return to the lead. If we still have serious disagreements about the lead we could seek a second opinion.

BTW you should register the fact that you're reviewing this at WP:GAN as soon as possible. -- Philcha (talk) 08:53, 31 October 2008 (UTC)

Right now, I cannot review the whole article. My 2¢ on the intro design (which I have interest in) was requested. You are right on the fact that most high taxa articles are too high profile (read: traffic) to remain GA. The only way I can think of to combat this is either a) lock the article or b) have less info to vandalize. The order Anura FA has been locked for a long time, with mild success. Some articles may be better off by withholding the details, and linking to external sites that are better suited, but this is kinda hard for a subphylum (unless there is a Chelicerata.com?). I am also contemplating the build-from-bottom-up vs. top-down notions. The latter seems illogical but is what I practice every day when writing. StevePrutz (talk) 15:01, 31 October 2008 (UTC)

I don't think the problem with the current GA / FA ratings on high-level taxa is to do with traffic or vandalism - the ones I mentioned lack citations and have gaps in coverage. Anura has too many unref'd passages to survive a reassessment. GA and FA have become significantly more demanding some time in the last 2 years.

Re bottom-up vs. top-down for packages of articles, I prefer bottom-up in paleontology, so I can see what the experts are talking about when they get on to phylogeny, etc. Bottom-up also means you have a big reserve of refs and re-usable text when you get to higher taxa. However that's more difficult for a sub-phylum with 77,000 species :-(

Either way it will often be necessary to make another pass in the opposite direction, to re-balance content between articles.

Since this is not a true GA review, I think it would be best to copy all this (except the references to GA review) to the normal Talk page and then blank the GA review page and unhook it from the Talk page. What do you think? -- Philcha (talk) 15:39, 31 October 2008 (UTC)

- - - - - end of review - - - - -

GA Review

This review is transcluded from Talk:Chelicerata/GA2. The edit link for this section can be used to add comments to the review.

I have finished my review of the article. Below is a checklist template filled out, and specific comments and questions below that. Let me know if you would like any clarification or additional comments. Theseeker4 (talk) 18:16, 5 December 2008 (UTC)

GA review (see here for criteria)

---

Nice article, no longer any reason to keep on hold, passing article to GA status..

1. It is reasonably well written.

   a (prose): b (MoS):

   Well written and seems to follow the manual of style sufficiently to meet the GA criteria.

2. It is factually accurate and verifiable.

   a (references): b (citations to reliable sources): c (OR):

   See the notes regarding citations formatting below

3. It is broad in its coverage.

   a (major aspects): b (focused):

   See the specific notes below

4. It follows the neutral point of view policy.

   Fair representation without bias:

5. It is stable.

   No edit wars etc.:

6. It is illustrated by images, where possible and appropriate.

   a (images are tagged and non-free images have fair use rationales): b (appropriate use with suitable captions):

7. Overall:

   Pass/Fail:

• I noticed a mistake/unclear internal link. In the major sub-groups section is the following section: "However the structure of "family tree" relationships within the Chelicerata has been controversial ever since the late 19th century. An attempt in 2002 to combine analysis of RNA features of modern chelicerates and anatomical features of modern and fossil ones produced credible results for many lower-level groups, but its results for the high-level relationships between major sub-groups of chelicerates were unstable, in other words minor changes in the inputs caused significant changes in the outputs of the computer program used (POY)." POY links to Time's Person of the Year. I am confident that this is not the proper link; I would bet that the link is supposed to go to the computer program used for this analysis, but that is not the case. This internal link should be either removed, or fixed. Theseeker4 (talk) 17:40, 5 December 2008 (UTC)

Unlinked. Why on earth did I think there was an article about the software? --Philcha (talk) 13:45, 7 December 2008 (UTC)

• The references section has differing formats. Some of the web-retreived sources are dated in the format "retrieved on 2008-11-6" for example, while others say "retrieved on 6 November 2008." This should be consistent throughout the article. (forgot to sign) Theseeker4 (talk) 17:53, 5 December 2008 (UTC)

Changed all to {{citation}} as that can handle any type of source that I've used. --Philcha (talk) 15:46, 7 December 2008 (UTC)

• The table titled "Diversity of living Chelicerates" under the Diversity section has a few groups with no data about their diet. If that information is not available (due to ambiguity of the fossil record for extinct groups, etc.), that should be noted in the table, or the information should be provided and cited. Theseeker4 (talk) 17:52, 5 December 2008 (UTC)

No sources that I've found says anything of the diet of Schizomida, Amblypygi, Palpigradi or Ricinulei as groups. Ditto for Google Scholar, although it finds reports of carnivory by individual species. The "default" for arachnids is carnivorous, but the diverse diets of Opiliones (harvestmen) and Acari (mites and ticks) make that assumption unsafe - and in 2007 a mainly vegetarian, social spider species was described. For these lesser-known groups the arachnidologists spend most of their time and ink trying to nail down the classification. It also looks like most groups for which "Diet" is blank are small to very small and live in environments that make observation very difficult, e.g. in leaf-litter or between soil grains. Taking the groups one at a time:

• Schizomida:
  • Ruppert, Fox & Barnes' Invertebrate Zoology (already cited) treats these as a sub-group of very small Uropygi, and implies that Uropygi are carnivores.
  • D.T. Anderson in chapter "The Chelicerata" of "Invertebrate Zoology" (ed. D.T Anderson; OUP, 2001; ISBN 0195513681) says nothing about Schizomida (rolls them up into "Pseudoscorpions"; only 1 para about Pseudoscorpions; treats Pseudoscorpions as carnivores)
  • The Neglected Cousins: What do we Know about the Smaller Arachnid Orders? argues for classifying them as a sister-group to Uropygi and that's about it. The author says outright that Uropygi are carnivores.
  • Google Scholar got me nothing about diet of Schizomida at all.
  • IMO it's best to leave this blank, as even "thought to be carnivores" would be pushing the sources too hard.
• Amblypygi:
  • Ruppert, Fox & Barnes' Invertebrate Zoology (already cited) says nothing about diet of Amblypygi.
  • D.T. Anderson in chapter "The Chelicerata" of "Invertebrate Zoology" (ed. D.T Anderson; OUP, 2001; ISBN 0195513681) says nothing about Amblypygi (rolls them up into "Pseudoscorpions"; only 1 para about Pseudoscorpions; treats Pseudoscorpions as carnivores)
  • Google Scholar got me nothing about diet of Amblypygi in general. Some species have been observed taking small birds and anuran amphibians.
  • "Carnivorous, where known" is the absolute max that can be squeezed out of the sources. IMO it's best to leave this blank.
• Palpigradi:
  • Ruppert, Fox & Barnes' Invertebrate Zoology (already cited) says nothing about diet of Palpigradi.
  • D.T. Anderson in chapter "The Chelicerata" of "Invertebrate Zoology" (ed. D.T Anderson; OUP, 2001; ISBN 0195513681) says nothing about Palpigradi (rolls them up into "Pseudoscorpions"; only 1 para about Pseudoscorpions; treats Pseudoscorpions as carnivores)
  • Google Scholar got me nothing about diet of Palpigradi in general, in fact nothing relevant.
  • IMO it's best to leave this blank.
• Ricinulei:
  • Ricinulei says carnivorous, but no source.
  • Ruppert, Fox & Barnes' Invertebrate Zoology (already cited) says nothing about diet of Ricinulei.
  • D.T. Anderson in chapter "The Chelicerata" of "Invertebrate Zoology" (ed. D.T Anderson; OUP, 2001; ISBN 0195513681) says nothing about Ricinulei (rolls them up into "Pseudoscorpions"; only 1 para about Pseudoscorpions; treats Pseudoscorpions as carnivores)
  • Google Scholar got me nothing about diet of Ricinulei in general, in fact nothing relevant.
  • IMO it's best to leave this blank.

I was under the impression that there was probably not enough information to fill in anything concrete. Rather than just leaving it blank, my first impulse would be to fill it in with "information not available" or "unknown," but if convention in similar articles is simply to leave it blank, I would certainly not say it has to be changed to pass GA review. Theseeker4 (talk) 14:02, 8 December 2008 (UTC)

I considered phrases like "information not available", "unknown" and "presumed carnivorous", but thought even those went too far beyond the reelvant sources I've found. --Philcha (talk) 15:56, 8 December 2008 (UTC)

• I read the lead section several times, and cannot determine any way to reduce the size without taking away from the content. The lead is a little large, but for the material covered, I do not see any way to reduce it. I would support the retention of the lead as-is, and respond to any "it's too long" arguments with a ignore all rules argument. Other than that, the above noted changes being made would allow this article to pass the GA review as far as I am concerned. Theseeker4 (talk) 18:16, 5 December 2008 (UTC)

Thanks! I'm beginning to think WP:LEAD needs to be changed for some types of subject, including phyla and sub-phyla. 2 previous GA reviewers, who AFAIK have do not interact much, concluded that it was best to accept long leads for article on high-level taxa. --Philcha (talk) 13:45, 7 December 2008 (UTC)

Hello, It seems to look good to me now. I will wait a bit for a response before I change anything myself, but I think the article is at the point where it can be promoted to GA status. Good job to everyone who worked on it, especially Philcha. Theseeker4 (talk) 14:05, 8 December 2008 (UTC)

• Passing GA Review I believe this article meets and exceeds all GA criteria. Good job to everyone involved. I think this article could even reach FA status with a little more work, as it is a very well-written and comprehensive article. Theseeker4 (talk) 16:43, 8 December 2008 (UTC)

References

- - - - End of Review - - -

Paraphyly in the picture http://en.wikipedia.org/wiki/File:Arthropod_head_problem_02.png on this page.

As I was reading this page today I noticed that the image http://en.wikipedia.org/wiki/File:Arthropod_head_problem_02.png as used on this page uses Tracheates as a taxon, which to my mind, and what I feel this is the consensus amongst scientists in relevant fields, is an invalid taxon as it appears to be paraphyletic. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1634985/

What would the best way to correct this be? I don't know how to work an image like this one. BullNiro (talk) 11:33, 27 May 2012 (UTC)

I agree the image is out-of-date. Quite a bit of this article needs updating. Relationships with other arthropods doesn't adequately reflect current consenus views properly (and right now doesn't have sources for the cladograms). Peter coxhead (talk) 10:11, 19 March 2016 (UTC)