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Talk:Fossils of the Burgess Shale

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Possible structure

That's a broader scope than I had anticipated - but I think it will work splendidly. Caron's recent palaeocommunity analysis should be a good source for the summary of animals found. I'll bagsie that bullet point for starters. Martin (Smith609 – Talk) 21:02, 24 April 2009 (UTC)
"a broader scope than I had anticipated"? I'd consider it seriously incomplete without any of these, and would fail it at GA ("broad coverage") if not remedied, never mind FA. --Philcha (talk)
I don't know Caron's recent palaeocommunity analysis, so you're better placed than me to do the "census" bit. I'd also say it's the highest priority, as we already have a ton of sources (and pastable text) for the rest, and covering the "usual suspects" w/o a census would probably cause loss of perspective. I think you've just put yourself in the firing line :-) --Philcha (talk) 22:10, 24 April 2009 (UTC)
Here it is... Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.palaeo.2007.05.023, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1016/j.palaeo.2007.05.023 instead.
Now to hope my weekend doesn't become as busy as it looks like it might... Martin (Smith609 – Talk) 01:33, 25 April 2009 (UTC)

Sources

This section is transcluded from Talk:Burgess Shale/Sources. The link to Talk:Burgess Shale/Sources can be used to add comments to it.

General

Location and topography

Geology & taphonomy ("How the fossil beds were formed")


Similar beds of similar age

History of fossil collecting there

Summary of fossils

Theoretical significance

Images


- - - - - - - End of transcluded text. Please add new discussion below this line; for the first one, edit the whole page - - - - - - -

Scientific points

The article's looking very good so far - your writing style is very agreeable these days! I appreciate you re-writing my contributions into accessible English - I had taken the approach of getting the information in there in any form, with the intent of re-writing it later once it had taken shape a little.

I understand, I sometimes do the same, especially if the phone rings or the cat miaows. --Philcha (talk) 17:34, 28 April 2009 (UTC)

I thought I'd best give the rest of the piece a quick skim, although unfortunately I don't have time to do anything more than that. I picked up on a couple of scientific points:

  • There is now compelling evidence that the BS was oxygenated. Anoxia cannot account for the preservation
  • Burrowing is also present in the BS; I think there's a paper discussing burrowing at the Chengjiang, which shows both that things are oxic, and that the sediments were partially disturbed
OK, add it and the citations. I thought Caron & Jackson (2006; "Taphonomy") already made those points quite well. --Philcha (talk) 17:34, 28 April 2009 (UTC)
  • There is good evidence that the sediment was bound in places (I think microbes are the only suggested reason for this)
Go for it. Can we w-link to Cambrian substrate revolution as well as microbial mat? --Philcha (talk) 17:34, 28 April 2009 (UTC)
  • 'THE defining feature' of BS type pres - this def needs sourcing; I'm not sure there's agreement on a definition of BStp.
I thought Butterfield (2003) was spot on - and my impression is that this is not new, see Wonderful Life (1989 - not quite BCE, but ...). --Philcha (talk) 17:34, 28 April 2009 (UTC)
  • Odontogriphus was a shell-less mollusc and is preserved. (FWIW there are other unpublished shell-less molluscs in the BS.) There are in fact quite a few things which could be tweaked in this paragraph - perhaps I should take a look at it.
Does that mean you think the Halwaxiid debate has been settled? --Philcha (talk) 17:34, 28 April 2009 (UTC)
BTW has Butterfield published anything on this since Pal. Ass. 2007? --Philcha (talk) 17:38, 28 April 2009 (UTC)

Anyhow, I like the shape things are taking, and look forward to doing a bit more work on the article myself! In the meantime, do you think it's worth getting some publicity at did you know? We'd need to nominate it today (or tomorrow at the latest). Martin (Smith609 – Talk) 16:35, 28 April 2009 (UTC)

That occurred to me, although the hook items I saw (Anomalocaris: The comedy, Aliens VI: Hallucigenia) did not seem to fit too well with the article's title. But if we can get away with using the title just as a link, not in the hook text, they would be good - unless you had something else in mind. --Philcha (talk) 17:34, 28 April 2009 (UTC)
Hiding the title behind a wikilink is fair game. Alternatively, we could go with something as broad as "The fossils of the Burgess Shale prompted a reinterpretation of the history of life" . (I'll address the other points anon.) Martin (Smith609 – Talk) 19:41, 28 April 2009 (UTC)

List of critters

I think it's long enough - currently Marrella, Opabinia, Anomalocaris and Hallucigenia representing the panarthropods, which started all the fuss; Wiwaxia, Odontogriphus and Orthrozanclus representig lophotrochozoan victims of Wiwaxia War I; Canadia to show that fossils can be fun even if not involved in a phylogenetic phrenzy; chordates, well, you know why.

However any selection is going to be controversial - if you explain it, someone will grumble about "editorialising" (that happened at Talk:Evolutionary history of life/GA1); if you don't, someone will demand a big essay, with citations, on why this particular lot of critters is particularly notable. Would it be worthwhile listing all the documented Burgess critters and linking to it? I'm thinking of a table sortable on name, date discovered (Anomalocaris will be interesting), site where first found, classification (yes, that's a can of invertebrates) - plus non-sortable "Comments" column (or head it "Brief description" to ward off WP:zealots). See the results tables at Alexander_Alekhine#Summary_of_results_in_competitions for an idea of how it would look. --Philcha (talk) 09:08, 29 April 2009 (UTC)

I think that so long as the text itself makes clear why the critters we mention are particularly notable, we should be okay. I can't think of any other 'must-includes' and if anybody wants to suggest why we are lacking, let's hear them out. No-one in their right minds is going to ask us to detail every single organism on this page, and I think that the current list is a great sample and fits the bill perfectly. Martin (Smith609 – Talk) 14:13, 29 April 2009 (UTC)

Orphaned references in Fossils of the Burgess Shale

I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Fossils of the Burgess Shale's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.

Reference named "Caron2006":

  • From Morania: Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1038/nature04894, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1038/nature04894 instead.
  • From Burgess Shale type preservation: Caron, Jean-Bernard; Jackson, Donald A. (2006). "Taphonomy Of The Greater Phyllopod Bed Community, Burgess Shale". Palaios. 21 (5): 451–465. doi:10.2110/palo.2003.P05-070R.

I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT⚡ 15:05, 30 April 2009 (UTC)

Preservation

I'm removing the "cn" tag as Butterfield 2003 (next sentence) covers this. From what I've seen FAC appears to dislike blue smallpox. If you think alternative defs of BS preservation need to be added, go for it - with citations, no maintenance tags, please. --Philcha (talk) 15:10, 30 April 2009 (UTC)

BTW you never did explain the "verification needed" tag you left in Mollusc#Fossil_record over 6 months ago. --Philcha (talk) 15:10, 30 April 2009 (UTC)

"The elements of the organism with a high preservation potential are those constructed of recalcitrant carbonaceous compounds" is dubious and probably inaccurate, e.g. Wiwaxia sclerites are not mineralized, and chitin appears to be a major candidate for BS preservation. I'll sort that out. --Philcha (talk) 15:10, 30 April 2009 (UTC)

I've made tried to make this less jargon-laden and to avoid the "recalcitrant carbonaceous compounds" issue, see what you think. --Philcha (talk) 15:49, 30 April 2009 (UTC)

You may be right about "This pattern may sometimes help palaeontologists, by indicating whether a group of organisms could have fossilized in a particular type of fossil bed, or by suggesting whether a body part was fairly tough like an arthropod limb (preserved as flat film) or very soft like a part of the gut (preserved as a solid piece of mineral)" needing clarification - I'll leave the tag in for a while to make me think about it. --Philcha (talk) 15:10, 30 April 2009 (UTC)

I've tried to clarify how it helps, see what you think. --Philcha (talk) 15:49, 30 April 2009 (UTC)

BTW I agree w your HTML comment about Canadian dialect, and I'm sure your hosts would agree, as there's bit of nationalism around the BS - but you'll have to copyedit when the content is stable, as I have no idea of the subtle differences between US and Canadian usage, spelling etc. --Philcha (talk) 15:49, 30 April 2009 (UTC)

As far as I can tell, Canadian uses Englsih spelling , but American words . I'll give it a once over when necessary (and deal with the other points when I'm awake). Martin (Smith609 – Talk) 21:34, 30 April 2009 (UTC)

I agree that "Beds may have subsequently been re-disturbed, and consequently may represent a 'time-averaged' community ..." (Caron & Jackson 2008) is a bit isolated. I didn't see in the source any explanation of how they might have been re-disturbed, what the evidence is, and how severe the re-disturbance can be (e.g. into the next higher burial layer). Have i missed something. --Philcha (talk) 16:42, 30 April 2009 (UTC)

It was probably me trying to qualify 'time-averaged' a bit - I think the term needs explaining, although I did a rather dire job. Other sources may be more useful? Martin (Smith609 – Talk) 19:40, 4 May 2009 (UTC)
I interpreted "time-averaged" in Caron & Jackson (2008) as referring to the fossils that clearly ceased to be alive before the burial events - molts & dissociated body parts.
Do you have some memories of sources that mention re-working? --Philcha (talk) 20:47, 4 May 2009 (UTC)

The lagerstätten a pause for breath in the radiation of animals?

SCM (1986) says the BS represents a pause for breath in the radiation of animals, which temporarily accelerated again in the mid-Ordov. The Chengjiang fossils are as similar to the BS ones as you could expect with a 15 MY gap, implying that the CEX ended before about 520 million years ago - but are there any sources for that? I don't know how much has been found at Sirius Passet or whether anyone's suggested how long that is after the actual end of the CEX. Can you fill in any of the gaps? --Philcha (talk) 07:57, 1 May 2009 (UTC)

1986 was a long time ago... there is no real definition of the "explosion"; every author has his own ideas about it. There was certainly a radiation in the Ordovician, and things probably settled down in the Late Cambrian (perhaps this is an illusion caused by extinctions?), but diversity is still increasing in the Burgess (Caron 2008). What we know is that there was nothing complicated in the mid-Ediacaran, and lots of complicated things by the Chengjiang, but we don't know much about in-between. This means we can't really say whether the difference between CJ and BS was at the same rate as before-hand, or slower. In 1986, understanding of the Ediacarans was limited, so it looked like everything appeared between the base of the Cambrian and the CJ - a relatively short time. But if we include the preC 'fuse', suddenly the explosion looks less sharp. I remember having a discussion with Graham Budd on these very pages where he derided any definition of the length of the explosion - so I think it's something best avoided! Martin (Smith609 – Talk) 14:01, 1 May 2009 (UTC)

Stratigraphy

Here's the most up-to-date discussion on stratigraphy: Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.palaeo.2009.02.012 , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1016/j.palaeo.2009.02.012 instead.

Significance

I've had a look at this section and I feel it's a little confused. It might help to lay out a structure for it - here's how I might modify your existing structure:

  • The traditional view is that animals appear from no-where at the base of the Cambrian. A few examples of why: SSF, sudden trilobites/echinoderms, poor stratigraphy.
  • No-body thought there was Precambrian life
  • Problems this caused: Darwin's confusion
  • Explosive interpretation
  • Gould's view on the BS as a post-explosion melange
    • Lots of phyla-from-nowhere
  • More recently, we have discovered:
    • Diverse Ediacaran biota (including modern phyla?)
    • Gradual increase in Cambrian complexity
    • Other Cambrian lagerstatte
    • How to classify oddballs
  • How is the BS significant now?
    • Potential of stem theory - relationships between modern groups, and their ancestral forms

Feel free to tweak as you please - if we agree on a structure it will make copy-editing each other a little easier. Martin (Smith609 – Talk) 18:19, 5 May 2009 (UTC)

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