Talk:Dickinsonia

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[edit] Taxobox

The {{missing taxobox}} template on the article page is problematic. It is not even clear that Dickinsonia is an animal, and any further classification would be contentious. I don't see any real point in providing a taxobox for this genus. -- Donald Albury 14:36, 10 February 2007 (UTC)

We could place it in Family Dickinsonidae, which currently includes also Yorgia and Marywadea.--Mr Fink 17:01, 10 February 2007 (UTC)

Few of the Ediacaran biota have any taxoboxes, and they don't have any agreed form of classification. Family Dickinsonidae is just one POV. Another POV I have read is that presumably evolution diverged groups over time, so that close to their point of divergence they were more closely related, so that different Phyla ancestors in the Ediacaran period would be as closely related as animals from different orders (or some smaller subdivision) are today. I was thinking along the lines of animalia and leave it at that! GB 06:05, 11 February 2007 (UTC)

Placing it in the Anamalia is a big POV! I think the classification of Dickinsonidae is fair - the PoV is whether that should be a family , genus, or phylum. That's a semantic, not factual, decision. Verisimilus T 00:09, 10 May 2007 (UTC)

[edit] New reference

The following reference could use incorporating into the article.

Retallack, G.J. (2007). "Growth, decay and burial compaction of Dickinsonia, an iconic Ediacaran fossil". Alcheringa: An Australasian Journal of Palaeontology 31 (3): 215-240. 

Thanks, Verisimilus T 13:29, 24 November 2007 (UTC)

I've incorporated it; a lot of facts referenced to this paper are referenced more securely within it and could use linking to their primary source. Also, the article now probably includes a bit too much of Redecker's point of view, something that could use addressing with a matter of urgency!

Verisimilus T 18:11, 22 January 2008 (UTC)

Well check out Zhang & Reitner (2006) (see here; that might help. IONO whether it is a good thing. Dysmorodrepanis (talk) 10:16, 9 March 2008 (UTC)

I don't seem to be able to view the article - the URL you gave just produces a chinese-character messagebox and a blank page. I can't find the article on google scholar, either. Do you have a full reference? Thanks. Verisimilus T 13:15, 9 March 2008 (UTC) Ah! Tracked it down using its title. My experience of Acta Geolgoica Sinica is that its reviewers are not quite as... incisive... as most peer reviewed journals. I've not managed to access the full text (would be interested if you had a copy), but would have my scruples with including it as a "reliable source"... Verisimilus T 13:23, 9 March 2008 (UTC)

You can drop your email on my Talk (as hidden annotation) and I'll send you the copy. I have just browsed it, it sounds reasonable though the conmclusion (a ctenophore ancestor) is of course open to debate. They report, as the abstract says, on a specimen that shows some internal structuring (it does not look like an artefact; too regular, too symmetrical). Yeah I know what you mean with the Acta bit... language barrier play a role at least in avian papers. But for the original purpose - to balance the lichen theory - this paper would seem rather good. Though it is perhaps a bit forceful, it discusses much of the theories surrounding Dickinsonia classification, and seeing that weird specimen it is hard not to consider the Zhang & Reitner opinion at least as warranted as any.

Did Retallack (2007) cite it? Google Scholar which knows both articles suggests no; the Retallack article is not accessible anymore in fulltext.

In any case, the article would source: "They are thicker at one end than the other, but there is no agreement as to which end is the front, and the organism does not appear to have a "head"." - there is a nice photo of a more conventional specimen (flattened out) that demonstrates this to good effect.

And of course, the concluding remark "It provides additional direct evidence for the hypothesis that metazoans began to diversify before the beginning of the Cambrian (Valentine et al., 1999; Fortey, 2001; Lieberman and Meert, 2004). It also implies that the first metazoan may have evolved before the Ediacaran" as well as the title "Removing It from Vendobionta" is at face value almost mainstream nowadays.

So I suppose the article is at least good and solid as a generalized discussion, however off it may be in its specific conclusion. Dysmorodrepanis (talk) 20:21, 9 March 2008 (UTC)

Thanks, I'll look forward to reading it. Brasier also has some specimens showing internal structure, which he believes resembles the structure of Charnia and so on - he's certainly not budged from his 2004 opinion that the organism is within a "Vendobionta"-like clade. Reverting to theories about early cnidaria strikes me as a backward step, but I'll be very interested to see the evidence!

NB hope you retrieve my e-mail address from your edit history. Verisimilus T 12:11, 10 March 2008 (UTC)

[edit] Very similar names

There's also a genus of (extant) tree fern called Dicksonia, which could be confused with this thing. 75.208.187.54 (talk) 01:25, 8 June 2008 (UTC)

That's true, though, do remember that the naming conventions of Taxonomy allow for a generic name to be used more than once, provided that the organisms being named are in different kingdoms, for example, Proteus being used to name a bacterium, and the olm.--Mr Fink (talk) 01:49, 8 June 2008 (UTC)