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Reason Why And why not it is a possible Echinoderm
Do I really have to explain myself here for what I'm trying to say? if so , then I will: The Reason why I consider this to be important enough to be here is because of how many people belive Arkarua To be the ancestor of all
echinoderms. In simple worlds, that isn't possible. In Complex Words: Arkarua Is Not At all An
Echinoderm , Because For one, the first Ever Echinoderm Proven To Be An Echinoderm Was Symmetric And Did not Have Five Way or Radial Symmetry at all, That Echinoderm being
Ctenoimbricata. Arkarua (in the image itself) IS Shown to posses 5-way Radial Symmetry , Such As Star Fish Or sea urchins, It Would Be impossible For An Animal With 5-way Radial Symmetry To have Bilateral Symmetry all of a sudden, Especially since It Doesn't look Like it even Evolved into Ctenoimbricata , Especially When it Looks Like A Relative Of A Creature Similar To it Such as
Aspidella. Oh yeah , it also lacks The Soft , Spongy Material called
stereom , especially When people call It "the earliest echinoderm".
I Am Simply Stating That it's Truly Impossibly For Arkarua to be The ancestor Of all echinoderms, If you Really Do Think that It is , I would Rather Appreciate That someone Edits this Page To add A List Of Reasons Why and Why not Arkarua is And isn't An Echinoderm. — Preceding
unsigned comment added by
Rugoconites Tenuirugosus (
talk •
contribs)
22:30, 29 January 2022 (UTC)reply
I wonder why this user is taking to such polemic language. The Question is not so absurd at all. The problem is complex, since undisputed echinoderms occur in the early middle cambrian in a wide diversity such as [Gogia], [edioasteroids], [helicoplacoids]. Some researchers propose that [Ctenocystoida] such as the early [Ctenoimbricata] are ancestral to echinodermata, mainly because of their approximate bilateral symmetry. The wide diversity strongly suggests that echinoderms already had a long history of evolutionary diversification in the early middle cambrian.
There are strong arguments that the ctenocystoids belong to the [Blastoza] and have secondarily lost the pentameral structure like other so-called [homalozoans].[1].
Thus, approximate bilateral symmetry of Ctenocystoida is not a strong argument per se, especially since even present echinoderms have bilaterally symmetric larvae and only get their pentameral radial structure as adults.
Marci68 (
talk)
12:14, 26 March 2023 (UTC)reply
References
^David, Bruno and Lefebvre, Bertrand and Mooi, Rich and Parsley, Ronald (2000). "Are Homalozoans Echinoderms? An answer from the extraxial-axial theory". Paleobiol. 26 (4): 529–555.
doi:
10.1666/0094-8373(2000)026$<$0529:aheaaf$>$2.0.co;2.{{
cite journal}}: CS1 maint: multiple names: authors list (
link)
This article is within the scope of WikiProject Palaeontology, a collaborative effort to improve the coverage of
palaeontology-related topics and create a standardized, informative, comprehensive and easy-to-use resource on Wikipedia. If you would like to participate, please visit the project page, where you can join
the discussion and see a list of open tasks.PalaeontologyWikipedia:WikiProject PalaeontologyTemplate:WikiProject PalaeontologyPalaeontology articles
Arkarua is within the scope of WikiProject Animals, an attempt to better organize information in articles related to
animals and
zoology. For more information, visit the
project page.AnimalsWikipedia:WikiProject AnimalsTemplate:WikiProject Animalsanimal articles
Arkarua is within the scope of WikiProject Australia, which aims to improve Wikipedia's coverage of
Australia and
Australia-related topics. If you would like to participate, visit the
project page.AustraliaWikipedia:WikiProject AustraliaTemplate:WikiProject AustraliaAustralia articles
This article is part of WikiProject Marine life, an attempt at creating a standardized, informative, comprehensive and easy-to-use resource on
marine life. If you would like to participate, you can choose to edit this article, or visit the
project page where you can join the project and/or contribute to the
discussion. This project is an offshoot of the WikiProject Tree of Life.Marine lifeWikipedia:WikiProject Marine lifeTemplate:WikiProject Marine lifeMarine life articles
This article is within the scope of
WikiProject Aquatic Invertebrates, a project which is currently considered to be inactive.Aquatic InvertebratesWikipedia:WikiProject Aquatic InvertebratesTemplate:WikiProject Aquatic InvertebratesAquatic Invertebrates articles
Reason Why And why not it is a possible Echinoderm
Do I really have to explain myself here for what I'm trying to say? if so , then I will: The Reason why I consider this to be important enough to be here is because of how many people belive Arkarua To be the ancestor of all
echinoderms. In simple worlds, that isn't possible. In Complex Words: Arkarua Is Not At all An
Echinoderm , Because For one, the first Ever Echinoderm Proven To Be An Echinoderm Was Symmetric And Did not Have Five Way or Radial Symmetry at all, That Echinoderm being
Ctenoimbricata. Arkarua (in the image itself) IS Shown to posses 5-way Radial Symmetry , Such As Star Fish Or sea urchins, It Would Be impossible For An Animal With 5-way Radial Symmetry To have Bilateral Symmetry all of a sudden, Especially since It Doesn't look Like it even Evolved into Ctenoimbricata , Especially When it Looks Like A Relative Of A Creature Similar To it Such as
Aspidella. Oh yeah , it also lacks The Soft , Spongy Material called
stereom , especially When people call It "the earliest echinoderm".
I Am Simply Stating That it's Truly Impossibly For Arkarua to be The ancestor Of all echinoderms, If you Really Do Think that It is , I would Rather Appreciate That someone Edits this Page To add A List Of Reasons Why and Why not Arkarua is And isn't An Echinoderm. — Preceding
unsigned comment added by
Rugoconites Tenuirugosus (
talk •
contribs)
22:30, 29 January 2022 (UTC)reply
I wonder why this user is taking to such polemic language. The Question is not so absurd at all. The problem is complex, since undisputed echinoderms occur in the early middle cambrian in a wide diversity such as [Gogia], [edioasteroids], [helicoplacoids]. Some researchers propose that [Ctenocystoida] such as the early [Ctenoimbricata] are ancestral to echinodermata, mainly because of their approximate bilateral symmetry. The wide diversity strongly suggests that echinoderms already had a long history of evolutionary diversification in the early middle cambrian.
There are strong arguments that the ctenocystoids belong to the [Blastoza] and have secondarily lost the pentameral structure like other so-called [homalozoans].[1].
Thus, approximate bilateral symmetry of Ctenocystoida is not a strong argument per se, especially since even present echinoderms have bilaterally symmetric larvae and only get their pentameral radial structure as adults.
Marci68 (
talk)
12:14, 26 March 2023 (UTC)reply
References
^David, Bruno and Lefebvre, Bertrand and Mooi, Rich and Parsley, Ronald (2000). "Are Homalozoans Echinoderms? An answer from the extraxial-axial theory". Paleobiol. 26 (4): 529–555.
doi:
10.1666/0094-8373(2000)026$<$0529:aheaaf$>$2.0.co;2.{{
cite journal}}: CS1 maint: multiple names: authors list (
link)