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Good articleCloudinidae has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Article milestones
DateProcessResult
June 5, 2007Good article nomineeListed
October 16, 2009Good article reassessmentKept
Current status: Good article

Untitled

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Cloudinid resembles the Silurian Period coral Tryplasma. Tryplasma, as pictured in the Fossil Detectives Field Guide, has root-like 'legs' which prop up their 'stack-of-shells'. Bigger organisms would grow bigger 'roots', and, hence, have bigger 'shell holes', as cited in the article, misconstrued (??) as evidence of predation. (That the holes scale with the organism size suggests a link to that organism, not 'other random predator animals'.) Corals are Cnidarians, which were on scene at the time. —Preceding unsigned comment added by 66.235.26.150 (talk) 16:17, 1 March 2011 (UTC)[reply]

Namapoikia rietoogensis

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"Namapoikia rietoogensis a calcareous sheet" There's clearly some mistake here, but I haven't a clue to what was intended...???

Namapoikia is a fossil that is in the form of a calcareous sheet--the text above is probably a typo of "Namapoikia rietoogensis, a calcareous sheet, ..." To be accurate, though, Namapoikia was not a calcareous sheet while it was alive--that's just the form its fossil takes. Cantabmiller 02:43, 4 May 2007 (UTC)[reply]

Good Article Discussion

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Can any one determine what the "link from Brain" and the "cited in Miller" red links are on the reference section? It would be good to eliminate these to improve the article. GB 10:52, 18 May 2007 (UTC)[reply]

Removed. Verisimilus T 14:41, 18 May 2007 (UTC)[reply]

The main text does not say who discovered the fossil, although it looks like GJ Germs in 1972 - is that the case? (I would not be eligible to assess this article so I will not give my opinion!) GB 11:00, 18 May 2007 (UTC)[reply]

Yes, it was first described by Germs. Is the taxobox statement insufficient? Verisimilus T 14:41, 18 May 2007 (UTC)[reply]

Hi, I was about to review but something came up....a couple of points:

It strikes me that Geological setting and Fossil locations are very similar in scope and should be combined into one section...we called sections Paleoecology or Paleobiology to highlight the different approach to modern lifeforms (i.e. fossil evidence rather than direct observation). cheers, Cas Liber | talk | contribs 07:29, 19 May 2007 (UTC)[reply]
In many other biology articles, Morphology I've called Description for conformity. Not a strong point though. cheers, Cas Liber | talk | contribs 07:30, 19 May 2007 (UTC)[reply]
..went extinct.. - became extinct better. cheers, Cas Liber | talk | contribs 07:30, 19 May 2007 (UTC)[reply]
Thanks for your interest in the article. I've restructured it to incorporate "Geological Setting", which I think certainly needed doing. However, I'd prefer to stick with the current section headings. Whilst I agree that Palæoecology should describe the study (or inference) of the ecology, what we're interested in here is what the thing did whilst it was alive, no matter how we obtained the data. As far as the Description/Morphology choice, I think the title "Morphology" is more consistent with the other section headings and has a more encyclopaedic tone to it. Verisimilus T 09:37, 19 May 2007 (UTC)[reply]


Successful good article nomination

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I am glad to say that this article which was nominated for good article status has succeeded. This is how the article, as of June 5, 2007, compares against the six good article criteria:

1. Well written?: checkY
2. Factually accurate?: As per above listed suggestions and fixes. checkY
3. Broad in coverage?: As far as I can tell. checkY
4. Neutral point of view?: checkY
5. Article stability? checkY
6. Images?: Could use some work here, but the infobox is enough for now. This is a place that further improvements should take place.

If you feel that this review is in error, feel free to take it to a GA review. Thank you to all of the editors who worked hard to bring it to this status. — Nswinton\talk 18:18, 5 June 2007 (UTC)[reply]

End-Ediacaran?

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The extinction event template {{ExtEvent nav}} currently links the minor extinction event titled "End-Ediacaran?" directly to this article, but there is no direct connection made to this expression in the currrent article. Indeed, one must read the entire article even to conjecture what is meant by this connection (unless, perhaps, one already knows the answer — a problem with all too many technical articles on Wikipedia). Could some of our domain experts here make a meaningful, sourced connection to this implication, or redirect the template's link to a more appropriate article? Thanks. ~ Jeff Q (talk) 20:19, 16 November 2007 (UTC)[reply]

A few points in response: first, the Extinction Event Template is inaccurate, as the geological time period in question is the Vendian and does not occupy all of the proterozoic (it goes from around 600 MA to the Cambrian). Second, it is generally accepted that Cloudina and its contemporaries died out at the Vendian-Cambrian boundary, so the link from the "End-Ediacaran" is appropriate, though I would think that linking to an article about the Vendian-Cambrian boundary and/or minor extinction would be a better fit. Cloudina is considered an index fossil for the terminal proterozoic (i.e., Vendian) because of this connection--if it existed afterwards, it wouldn't make a very good index fossil. Cantabmiller (talk) 01:05, 11 December 2007 (UTC)[reply]
The Ediacaran period was formally ratified in ~2004, with the term "Vendian" no longer in use. The end of the Ediacaran, surely, is the "Vendian-Cambrian boundary"? And some fossils are excellent index fossils in some parts of the world, where the same species may have wider temporal distributions elsewhere. The selection of a fossil as an index is not necessarily a statement as to the presence of a mass extinction. But: a separate page discussing the presence or otherwise of such an End-Ediacaran event would be a valuable addition to Wikipedia. Verisimilus T 19:53, 13 December 2007 (UTC)[reply]
Good point about Vendian/Ediacaran--it's been a while since I've been immersed in the literature on the period names (and the reference I used in my reply above was sadly out of date). So, when I say Vendian above, it should be replaced with Ediacaran; thus, Cloudina and its contemporaries died out at the Ediacaran-Cambrian boundary, and calling it the end-Ediacaran is probably fine (I don't know if there's an accepted term for this extinction event). I agree that the designation of a fossil as an index is not necessarily a statement as to the presence of a mass extinction, but it is a statement as to the presence of the extinction of the species considered an index fossil. My point, poorly made, was that the reason someone linked end-Ediacaran to Cloudina is likely because Cloudina went extinct at that boundary (I do not know why they did not choose one of the other species that went extinct at the same time, so I agree that the selection is misleading if someone is looking for the complete story of the end-Ediacaran). I did not mean to imply that index species are only used to indicate a mass extinction. Cantabmiller (talk) 19:49, 27 December 2007 (UTC)[reply]

Why the redirect?

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Why is there a redirect from "Cloudina" to a page on "Cloudinid" when "Cloudina" is the sole genus anyway? This doesn't make much sense to me. 75.210.160.201 (talk) 22:35, 5 June 2008 (UTC)[reply]

Because otherwise there's be a redirect from "Cloudinid" to "Cloudina" when Cloudina is the only member of the Cloudinids? Martin (Smith609 – Talk) 21:43, 3 August 2008 (UTC)[reply]

"Predatory borings" in Cloudina

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The evolution of external shells in the Late Ediacaran is thought to be a defence against predators, marking the start of an evolutionary arms race. The holes made by predators are approximately proportional to the size of the Cloudina specimens, and Sinotubulites fossils, which are often found in the same beds, have so far shown no such holes. These two points suggest that predators attacked in a selective manner, and the evolutionary arms race which this indicates is commonly cited as a cause of the Cambrian explosion of animal diversity and complexity.

However, the skeleton is not only protection, but also a support. The own stone pedestal makes it easy to rise above others or, at least, above sea bottom.[1] Zhuravlyov's new researches of the Cloudina reinterpreted of "predatory borings" as a craters which remained after of destruction/fall out of the dolomite crystals which cover the Cloudina fossils surface. The undamaged holes have a square form that is not characteristic for any borers. Zhuravlyov joke: "If only it the strangers from parallel worlds, as always, have drilled a quadrangular apertures in the skeletons." [1]

While predatory borings are common in Cloudina specimens, no such borings have been found in Sinotubulites. It has very simple explanation. In life the Cloudina shell have consisted of high-Mg calcite[2], therefore the Cloudina shell is covered by dolomite crystals, the Sinotubulites have consisted of aragonite[2], therefore no Mg => no dolomite crystals => no "predatory borings".

References:

  1. Andrey Yu. Zhuravlev (2006). "The skeletal Precambrian". Priroda (in Russian). 12: 37–40.
  2. Andrey Yu. Zhuravlev, Rachel A. Wood (2008). "Eve of biomineralization: Controls on skeletal mineralogy" (PDF). Geology. 36 (12): 923–926.

See also:

Aleksey (Alnagov (talk) 19:26, 19 March 2009 (UTC))[reply]

shells

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the image showing living space within the shell displays the shells with a test-tube like bottom. however, in the actual article it says that research suggeats the animals shells did not have test-tube like bases. may someone make a new image to show how cloudinias shells looked like according to current understanding?

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