Talk:Cambrian

message: The link to the Florian subsection of time is currently redirected to a certain St. Florian. Disambiguation and expansion with more information than I have is in order. 67.171.194.78 00:00, 12 January 2006 (UTC)
thread_title: Untitled

message: Aside from a few enigmatic forms that may or may not represent animals, all modern animal phyla with any fossil record to speak of (except bryozoans) appear to have representatives in the Cambrian, and of these most except sponges seem to have originated just after or just before the start of the period. However, several modern phyla, primarily those with small and/or soft bodies, have no fossil record, in the Cambrian or otherwise.
What a mess those two sentences are. First it says that all modern phyla are represented, then it says some aren't. And are the "few enigmatic forms" from the Cambrian, or are they current (I'll take a guess at cambrian, but I shouldn't have to)? The structure of this part is very confusing, and should be sorted out. Totnesmartin 17:39, 4 March 2007 (UTC)
replies: text: It's a very nice contradiction - that's what it is. It demonstrates bold attack followed by cowardly retreat. I'll take a look. Said: Rursus ☻ 12:18, 2 December 2007 (UTC)

text: Now reformulated. Said: Rursus ☻ 12:25, 2 December 2007 (UTC)
thread_title:  Confusing statement 

message: The article currently includes uses of both Ma and mya. My sense is that this should be standardized on one or the other, or is there a reason to use both forms? WilliamKF (talk) 19:14, 30 November 2008 (UTC)
thread_title:  Ma vs mya 

message: It sounds like there is an extinction event at both the beginning and end of this period. However, I wasn't certain after reading. I feel some rework is needed around this concept to clarify it in the text. WilliamKF (talk) 19:37, 30 November 2008 (UTC)
thread_title:  Extinction events 

message: "The participants of the symposium pointed out the following: (1) The officially approved stratotype of the Lower Cambrian boundary for the base of the Cambrian at the Burin Peninsula, Newfoundland is inadmissible due to the insecure principle of using of ichnofossils for correlation, very poor faunal characteristics of the section, the absence of possibility to obtain detailed paleomagnetic and isotopic data. The problems of another possible principle for substantiation of this particular stratigraphic boundary and, consequently, another sections for the stratotype of the base of the Cambrian, were discussed. The "Dvortsy" Section on the Aldan River, Siberia was suggested as the most suitable candidate for the Lower Cambrian boundary stratotype (explanation: it is base of the Tommotian). ... (3) The major result of the symposium is the scheme proposed for the subdivision of the Lower Cambrian into stages, with a nomenclature, each stage stratotype and each lower boundary stratotype. It was reached a decision to send this scheme as the base of the nomenclature or a working model for the Lower Cambrian stages to the Subcommission of the Cambrian System. .... It was concluded that the most suitable level for GSSP of the Lower Cambrian boundary is the FAD of the mollusk Aldanella attleborensis, associated with the appearance of the first archaecyaths"
Free text: http://vendian.net76.net/Lower_Cambrian.pdf
:Remember though that at present, the Tommotian stage is only regionally used, in Siberia. Where Russian stratigraphers establish the base of their Tommotian division has no meaning to the rest of the world, which uses the Fortunian ICS stage. There seems to be a dispute between Russian and American stratigraphers going on, which is probably more political than scientific in nature. Therefore I doubt this information is important enough to be included in the article. What seems important to me is: A the information that the Cambrian is officially subdivided into four series and twelve stages, most of which haven't been named yet; B the names of the internationally recognized stages and series; C that local subdivisions are widely used too, of which the Siberian is an important one; D the name Tommotian (and other Siberian names) can be used in this article, but not in the current predominant way (the Siberian stratigraphic subdivision is given unequal weight -this is a POV!). Best regards, Woodwalker (talk) 12:32, 17 August 2009 (UTC)
replies: text: Where ignorance, there negation and emptiness. Aleksey (Alnagov (talk) 11:54, 18 August 2009 (UTC)
replies: text: So okay, what part of that was ignorant? Or are you opposed to using the ICS timescale as a reference at Wikipedia? Please give a constructive reaction instead of being cryptic. Woodwalker (talk) 12:42, 18 August 2009 (UTC)
thread_title:  To the problem of the Lower Cambrian boundary and subdivision 

message: Do we really want the Cambrian and Precambrian represented in the geological period template by an "E"?  I can see that we want to avoid ambiguity with the Cretaceous and Carboniferous, but can't we do that by just choosing different colours and retaining "C"? And how do we edit the geological period template? --Michael C. Price talk 12:04, 15 December 2009 (UTC)
replies: text: The standard symbol for the Cambrian in geologic maps is a capital C with a horizontal bar through it. It may look like an E. Woodwalker (talk) 18:24, 15 December 2009 (UTC)
replies: text: Thanks. --Michael C. Price talk 20:24, 15 December 2009 (UTC)
thread_title: Symbol

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thread_title:  Reference to broken DOI 

message: Why is Є representative of Cambrian?  The symbol appears only in the color-coded bar in the upper right, with no explanation in the article. Spril4 (talk) 02:34, 27 July 2010 (UTC)
replies: text: To avoid confusion with the Carboniferous? (I asked the same question ) --Michael C. Price talk 04:07, 27 July 2010 (UTC)
thread_title:  Є? 

message: Hi there.  In the Subdivisions section the article reads, (499 ± 2 million years ago to 488.3 million years ago million years ago ; also known as Late Cambrian, Merioneth or Croixan).  There's an extra "million years ago" in there, but there's some period span code used and I don't know how to fix it.  Any takers? --Smoggyrob | Talk 05:59, 2 September 2010 (UTC)
thread_title:  Millions and millions 

message: What mark the base of Tommotian?  For example, FAD of Treptichnus pedum in the Fortune Head, Newfoundland mark the base of the Cambrian. Mikelemot (talk) 21:09, 30 October 2011 (UTC)
thread_title:  What mark the base of Tommotian? 

message: At last it happens! The leading members of the International Subcommission on Cambrian Stratigraphy recognized the failure of the GSSP of the base of the Cambrian System in the Fortune Head section, Newfoundland, and Treptichnus pedum as its marker.
:"In the future, when most Cambrian GSSPs are established, it will be necessary to restudy the definition of the GSSP at the base of the Cambrian System. A problem has arisen with the ichnofossil whose FAD has been defined as coinciding with the base of the Cambrian. Subsequent to ratification of the GSSP in the Fortune Head section, Newfoundland, Trichophycus pedum has been found at horizons 3.11 m and 4.41 m below the GSSP point in the stratotype section (Gehling et al. 2001). Zigzag traces of Trichophycus sp. have been found even farther below the GSSP level in the stratotype. After re-examination of the occurrences of trace fossils in the Fortune Head section, Gehling et al. (2001) recommended a re-evaluation of the stratigraphic ranges and taxonomic assignments of ichnotaxa there. In addition to the issue of identifying the horizon containing the Cambrian GSSP on trace fossil evidence, there are no stratigraphic tools other than trace fossil assemblages that can be used to constrain the GSSP in the stratotype, nor to correlate the horizon outside its place of definition. This means that the GSSP level, or the T. pedum FAD level, has never been confidently recognized in any section in the world apart from Fortune Head. This casts doubt on the international correlation utility of this GSSP."
Aleksey (Alnagov (talk) 11:44, 11 November 2011 (UTC)
thread_title:  Future of the GSSP of the base of the Cambrian System 

message: Under the fauna section comes the flora section. This section only mentions the lack of land plants, other than algae, etc, and does not cover sea plants, which I'm pretty sure were present. Can anyone add this information?  — Preceding unsigned comment added by 67.232.30.10 (talk) 15:03, 7 March 2012 (UTC)
thread_title:  Fauna 

message: Hey guys, I noticed the map detailing different continents/etc during the Cambrian is missing, why? Also, I remember a better map being added a while back, why was it removed? I didn't bother reading the rest of the talk page.
--76.226.76.64 (talk) 00:12, 27 March 2012 (UTC)
thread_title:  Geography? Map? 

message: I mean this in the most supportive way possible. In a technical, scientific article, generalizations having no useful content can be distracting and annoying. This article has its share. I am moved to this view in particular having just read "Cambrian rocks are very old...."  Well, yes, one could safely assume that to be the case. All things Cambrian are "very old" but so is the Tower of London. I don't want to copy-edit; I think perhaps the original writer intended some point but failed to express it well. Thanks to all who contribute.SteveO1951 (talk) 17:47, 1 April 2012 (UTC)
replies: text: I've removed those sentences that weren't really saying anything specific to the Cambrian - thanks for pointing that out. Mikenorton (talk) 21:08, 1 April 2012 (UTC)
thread_title:  Stating the obvious 

message: It is not a browser issue either - I checked IE, Firefox and Chrome and they all show the same problem.
I tried my hand at editing it, but could not figure out how to get the blank lines between letters in the vertical "span" text to disappear. That is one of the things causing labels to spill over the boxes provided for them. 
Commutator (talk) 06:03, 28 October 2012 (UTC)
thread_title:  Key events timeline is messed up 

message: The article does not give a reliable statement of prevailing climate during the Cambrian.
The lead states "The seas were relatively warm, and polar ice was absent for much of the period."
The Palaeogeography section refers to "a lack of sea ice"  "the sea level was high"  "the continents being flooded in warm, shallow seas"  "The sea levels fluctuated somewhat, suggesting that there were 'ice ages', associated with pulses of expansion and contraction of a south polar ice cap." - All apparently good cited stuff.
Then the Climate section paints a different, contradictory (and unsourced) picture: stating
"The Earth was generally cold during the early Cambrian, probably due to the ancient continent of Gondwana covering the South Pole and cutting off polar ocean currents. There were likely polar ice caps and a series of glaciations, as the planet was still recovering from an earlier Snowball Earth. It became warmer towards the end of the period; the glaciers receded and eventually disappeared, and sea levels rose dramatically. This trend would continue into the Ordovician period."
I don't have enough knowledge of the palaeoclimate evidence of this period to correct this - I came to the article for information on it - but is there another editor around who can put this right??  Plantsurfer (talk) 10:00, 19 April 2013 (UTC)
thread_title:  Conflicting statements about Climate 

message: ...is probably an important element that needs to be added to the article. Anyone feeling up to the task? Belsavis (talk) 11:56, 3 November 2013 (UTC)
thread_title:  The appearance of terrestrial fungi in the Cambrian 

message: Why does the lead of the this article contain detailed information on making the symbol for the Cambrian? Much less, why is it even necessary? Is it so important that the symbol "Є" be covered at all? I've commented it out, but only on the grounds that this is baffling. If it must be kept, surely it can be moved out of the introduction. Or even footnoted if it is given to be so important that means of its insertion need be discussed. 209.255.230.32 (talk) 12:57, 6 November 2013 (UTC)
replies: text: A single sentence is not exactly putting too much weight on it. It is discussed because it is widely used. The information is factual and can be reliably sourced. Wikipedia itself uses it. See the fossil range bar in the infobox on the right. I wouldn't object to moving it elsewhere though. But as of now, I can't really see any subsection where it would fit.-- OBSIDIAN†SOUL 18:26, 7 November 2013 (UTC)
thread_title:  Symbol 

message: The second paragraph of the lede says, "The Cambrian marked a profound change in life on Earth; prior to the Cambrian, the majority of living organisms on the whole were small, unicellular and simple; the Precambrian Charnia being exceptional." First, the majority of organisms today are on the whole small, unicellular and simple. Secondly, our own article on Ediacaran biota describes a variety of complex life forms, indicating that Charnia was not exceptional. Zyxwv99 (talk) 17:52, 6 September 2016 (UTC)
thread_title:  Precambrian 

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thread_title:  External links modified 

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thread_title:  External links modified 

message: The relationship between the "Montezuman" North American stage and the ICS scale as depicted in the table doesn't match the numbers I'm getting from other sources (~530-525 Ma). What gives? Abyssal (talk) 08:44, 20 November 2017 (UTC)
thread_title:  Montezuman 

message: Is the correct symbol for this period Є or Ꞓ? This article uses Є; Є redirects to Ukrainian Ye. There, at Ukrainian Ye#Related letters and other similar characters, we find Ꞓ, described as a Latin letter—but the description, "Latin letter Ꞓ", links to Ꞓ—which links back here, to Cambrian, rather than to an article about that letter. So it's unclear to me which of the two glyphs is actually the symbol for the Cambrian period. Largoplazo (talk) 17:32, 5 December 2017 (UTC)
replies: text: The symbol Є is not correct. Cambrian period marked by the Latin symbol Ꞓ. Geologic Age Symbol Font. But Ꞓ not always correctly displayed in Internet browsers. Aleksey (Alnagov (talk) 10:33, 6 December 2017 (UTC)
replies: text: Ah, I see. Because now I'm on browser at home (Windows 7) and can't see the Ꞓ, whereas it displayed properly on my office computer (Windows 10) yesterday. Thanks. Largoplazo (talk) 12:23, 6 December 2017 (UTC)
thread_title:  Which symbol? 

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thread_title:  External links modified (January 2018) 

message: The table lists the ICS series, but only various regional stages, not the ICS ones where they exist. Is there a reason for this? Orcoteuthis (talk) 13:24, 18 January 2021 (UTC)
thread_title:  Subdivisions 

message: Please update the link in ref [1] after "Subdivision of the Cambrian according to the ICS, as of 2021.[1]" to point to its new address https://stratigraphy.org/timescale/
Martin (Smith609 – Talk) 11:00, 28 June 2022 (UTC)
replies: text: Thanks for reporting this. The fix required a change to Template:Cambrian graphical timeline, which I have done. GeoWriter (talk) 18:40, 28 June 2022 (UTC)
thread_title:  ICS link 

message: The introduction says "Cambrian WAS the first geological period of Paleozoic...", while other periods have this verb in the form IS. Which one is correct then? Jack Jackie Pomi (talk) 14:22, 15 August 2022 (UTC)
thread_title:  "Was" or "Is"