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This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 September 2020 and 11 December 2020. Further details are available
on the course page. Student editor(s):
Vanessazelaya.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 06:43, 17 January 2022 (UTC)
In the "See Also" section, do people think it's best to leave Dunkleosteus terrelli as it is, pointing at a redirect, or change it to Dunkleosteus terrelli, which doesn't redirect but doesn't look as nice. 193.63.43.10 13:32, 26 March 2007 (UTC)
I'll have to delete this link, the article doesn't work http://www.amonline.net.au/archive.cfm?id=1137
-- HoopoeBaijiKite 20:50, 18 June 2007 (UTC)
Why is it so horrible to use this picture [1] in the taxobox?-- Mr Fink ( talk) 05:18, 21 April 2008 (UTC)
" ...when more fossil specimens were found, especially the exceptionally well-preserved fossils from the Gogo Reef formation in Australia, Stensiö's theory of sharks and placoderms as sister groups became accepted as fact."
This statement is misleading. While Stensiö's work remains highly respected, the idea of a sister-relationship between chondrichthyians and placoderms has been almost universally rejected by vertebrate palaeontologists since the mid-1990s. The current consensus is that placoderms are stem-gnathostomes and are thus no more closely related to sharks than bony fish are. The Gogo fossils provided strong evidence *against* a placoderm-shark relationship (Gogo placoderms show separate bone for the nasal capsules which are incorporated into the braincase of sharks and bony fish). If no one objects, I will rewrite this section ASAP.
REFS = Goujet, Daniel & Young, Gavin (2004). Placoderm anatomy and phylogeny: new insights. (in) Arratia, Wilson and Cloutier (eds) Recent Advances in the Origin and Early Radiation of Vertebrates. Verlag Dr. Friedrich Pfeil, Munchen, Germany.
Young, G.C. & Goujet, D. & Lelievre, H. (2001) Extraocular muscles and cranial segmentation in primitive gnathostomes - fossil evidence. J. Morphology. 248:304.
Phillipe Janvier's page at the tree of life = http://www.tolweb.org/Gnathostomata/14843
John Long - personal communication.
Ozraptor4 ( talk) 01:46, 13 June 2008 (UTC)
This article is well done, but conspicuously omits information that would describe the connections between Placodermi and other lineages of fish. Contextual information of this kind was what I was looking for. Janice Vian, Ph.D. ( talk) 16:59, 15 November 2012 (UTC)
Shouldn't all of the orders end at the end of the Devonian? I've never heard of any ptyctodontids surviving into Early Carboniferous time.--Mr Fink 05:49, 19 February 2013 (UTC)
Here's another issue. Should the drawing of Coccosteus decipiens, used as the basis for the anatomy diagram, have an anal fin? -- Epipelagic ( talk) 08:01, 23 February 2013 (UTC)
The deleted part says "The males reproduced by inserting a long clasper, the basipterygium that was fused to part of the pelvic girdle." This is no longer correct, as the new link explains in the article: "Unlike the claspers of modern sharks and rays that are a part of the paired pelvic fins, the claspers and female basal plates in placoderms were not at all connected to that fin."
Neither are they no longer considered the sister group to all jawed vertebrates, but their direct ancestors, as mentioned in the article about Gnathostomata. 84.210.10.52 ( talk) 13:07, 29 June 2014 (UTC)
The article included the claim that ptyctodontids are paraphyletic with respect to the gnathostome crown. This wasn't something I've seen claimed before so I looked into the cited source; but it's an article about acanthodians. There is a gnathostome phylogeny presented there, but it finds ptyctodontids as the monophyletic sister group to crown-Gnathostomata + Entelognathus. For now I've removed the claim as a probable mistake. Kaficek ( talk) 12:47, 1 January 2017 (UTC)
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I wonder if these animals were like lampreys in that they could regenerate body parts bitten off in a fight. E.g. https://phys.org/news/2019-01-lamprey-regenerates-spinal-cord-oncebut.amp
Lampreys can regenerate whole spinal cord Lollipop ( talk) 02:17, 4 May 2019 (UTC)
The External anatomy of the placoderm Coccosteus decipiens diagram depicts an armored head with external bones and a "naked" body. This is inaccurate as placoderms did indeed have external integument on their heads--unlike ostracoderms, it's more than likely they didn't just have bones on the outside of their heads and no skin. Entelognathus ( talk) 17:50, 16 March 2021 (UTC)
Is the citation to Li et al. (2021) in the introduction correct? Where in that paper does it offer a rebuttal to King et al. (2016), and how does it solidy the paraphyletic status of placoderms? These things are not explicitly mentioned in the paper. Bohiggin ( talk) 14:05, 28 December 2021 (UTC)
This paper seems to describe a placoderm from Carboniferous deposits https://www.biodiversitylibrary.org/bibliography/15102 Bubblesorg ( talk) 19:30, 21 October 2022 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||||||||
|
This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 September 2020 and 11 December 2020. Further details are available
on the course page. Student editor(s):
Vanessazelaya.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 06:43, 17 January 2022 (UTC)
In the "See Also" section, do people think it's best to leave Dunkleosteus terrelli as it is, pointing at a redirect, or change it to Dunkleosteus terrelli, which doesn't redirect but doesn't look as nice. 193.63.43.10 13:32, 26 March 2007 (UTC)
I'll have to delete this link, the article doesn't work http://www.amonline.net.au/archive.cfm?id=1137
-- HoopoeBaijiKite 20:50, 18 June 2007 (UTC)
Why is it so horrible to use this picture [1] in the taxobox?-- Mr Fink ( talk) 05:18, 21 April 2008 (UTC)
" ...when more fossil specimens were found, especially the exceptionally well-preserved fossils from the Gogo Reef formation in Australia, Stensiö's theory of sharks and placoderms as sister groups became accepted as fact."
This statement is misleading. While Stensiö's work remains highly respected, the idea of a sister-relationship between chondrichthyians and placoderms has been almost universally rejected by vertebrate palaeontologists since the mid-1990s. The current consensus is that placoderms are stem-gnathostomes and are thus no more closely related to sharks than bony fish are. The Gogo fossils provided strong evidence *against* a placoderm-shark relationship (Gogo placoderms show separate bone for the nasal capsules which are incorporated into the braincase of sharks and bony fish). If no one objects, I will rewrite this section ASAP.
REFS = Goujet, Daniel & Young, Gavin (2004). Placoderm anatomy and phylogeny: new insights. (in) Arratia, Wilson and Cloutier (eds) Recent Advances in the Origin and Early Radiation of Vertebrates. Verlag Dr. Friedrich Pfeil, Munchen, Germany.
Young, G.C. & Goujet, D. & Lelievre, H. (2001) Extraocular muscles and cranial segmentation in primitive gnathostomes - fossil evidence. J. Morphology. 248:304.
Phillipe Janvier's page at the tree of life = http://www.tolweb.org/Gnathostomata/14843
John Long - personal communication.
Ozraptor4 ( talk) 01:46, 13 June 2008 (UTC)
This article is well done, but conspicuously omits information that would describe the connections between Placodermi and other lineages of fish. Contextual information of this kind was what I was looking for. Janice Vian, Ph.D. ( talk) 16:59, 15 November 2012 (UTC)
Shouldn't all of the orders end at the end of the Devonian? I've never heard of any ptyctodontids surviving into Early Carboniferous time.--Mr Fink 05:49, 19 February 2013 (UTC)
Here's another issue. Should the drawing of Coccosteus decipiens, used as the basis for the anatomy diagram, have an anal fin? -- Epipelagic ( talk) 08:01, 23 February 2013 (UTC)
The deleted part says "The males reproduced by inserting a long clasper, the basipterygium that was fused to part of the pelvic girdle." This is no longer correct, as the new link explains in the article: "Unlike the claspers of modern sharks and rays that are a part of the paired pelvic fins, the claspers and female basal plates in placoderms were not at all connected to that fin."
Neither are they no longer considered the sister group to all jawed vertebrates, but their direct ancestors, as mentioned in the article about Gnathostomata. 84.210.10.52 ( talk) 13:07, 29 June 2014 (UTC)
The article included the claim that ptyctodontids are paraphyletic with respect to the gnathostome crown. This wasn't something I've seen claimed before so I looked into the cited source; but it's an article about acanthodians. There is a gnathostome phylogeny presented there, but it finds ptyctodontids as the monophyletic sister group to crown-Gnathostomata + Entelognathus. For now I've removed the claim as a probable mistake. Kaficek ( talk) 12:47, 1 January 2017 (UTC)
Hello fellow Wikipedians,
I have just modified 4 external links on Placodermi. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
RfC before doing mass systematic removals. This message is updated dynamically through the template {{
source check}}
(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 09:45, 20 December 2017 (UTC)
I wonder if these animals were like lampreys in that they could regenerate body parts bitten off in a fight. E.g. https://phys.org/news/2019-01-lamprey-regenerates-spinal-cord-oncebut.amp
Lampreys can regenerate whole spinal cord Lollipop ( talk) 02:17, 4 May 2019 (UTC)
The External anatomy of the placoderm Coccosteus decipiens diagram depicts an armored head with external bones and a "naked" body. This is inaccurate as placoderms did indeed have external integument on their heads--unlike ostracoderms, it's more than likely they didn't just have bones on the outside of their heads and no skin. Entelognathus ( talk) 17:50, 16 March 2021 (UTC)
Is the citation to Li et al. (2021) in the introduction correct? Where in that paper does it offer a rebuttal to King et al. (2016), and how does it solidy the paraphyletic status of placoderms? These things are not explicitly mentioned in the paper. Bohiggin ( talk) 14:05, 28 December 2021 (UTC)
This paper seems to describe a placoderm from Carboniferous deposits https://www.biodiversitylibrary.org/bibliography/15102 Bubblesorg ( talk) 19:30, 21 October 2022 (UTC)