化石講場-Fossils Board » [古生物新聞 Paleontology News] » Ediacara Biota are confirmed to be Animals

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Dinosaurprince2018-9-21 04:25 PM
Ediacara Biota are confirmed to be Animals

[url]https://www.theatlantic.com/science/archive/2018/09/the-oldest-known-animal-is-wait-seriously-what-is-that/570865/?utm_medium=social&utm_source=facebook&utm_term=2018-09-20T18%3A00%3A23&utm_campaign=the-atlantic&utm_content=edit-promo[/url]

[url]https://www.bbc.com/news/science-environment-45588213[/url]

Devonian2018-9-23 08:42 AM
Ediacara Biota 記得一直都認為是最早的動物

fossilshk2018-9-24 11:26 AM
5.58億年前狄更遜水母化石證明為動物始祖

「科學雜誌」(Science)今天發布的報告顯示,一個從俄羅斯懸崖挖出的狄更遜水母(Dickinsonia)化石,經研究人員分析成分後發現有屬於一種脂肪的膽固醇分子,證實是地球上已知最早的動物。


英國「獨立報」(Independent)報導,澳洲國立大學地球科學研究所副教授布羅克斯(Jochen Brocks)表示,科學家超過75年來對這怪異化石的本質爭論不休,並說:「脂肪成分證實狄更遜水母化石是已知的最早動物,解決已成為古生物學聖杯的數10年之謎。」



狄更遜水母呈肋狀的橢圓形,尺寸各異,可以長到1.4公尺。布羅克斯表示,分析報告顯示這些生物在5.58億年前比比皆是,較之前推算時間早數百萬年。

這種生物是埃迪卡拉生物群(Ediacara Biota)的一部分,出現在6億3500萬到5億4200萬年前細菌統治的地球上。埃迪卡拉紀是寒武紀生命大爆發前約2000萬年的時期。

先前已有諸多研究人員宣稱解開狄更遜水母這個古怪化石之謎,認為它是最原始的動物,但因有段時間找不到有機物的成分,無法直接確認是否為動物。不過,在俄羅斯西北方的白海附近的懸崖發現有機物仍完整的狄更遜水母化石。

加州大學地球生物學家兼助理教授高德(DavidGold)表示:「這是古生物學這個領域文藝復興的一部分。」並說:「這份報告是另一個非常好的證據,證明這個化石是動物,甚至比寒武紀還古老。」

fossilshk2018-9-25 05:39 AM
[quote]原帖由 [i]Dinosaurprince[/i] 於 2018-9-22 12:25 AM 發表
[url]https://www.theatlantic.com/science/archive/2018/09/the-oldest-known-animal-is-wait-seriously-what-is-that/570865/?utm_medium=social&utm_source=facebook&utm_term=2018-09-20T18%3A00%3A23&[/url] ... [/quote]
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<iframe width="560" height="315" src="https://www.youtube.com/embed/7J7lBv_qmiI" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

Dinosaurprince2018-9-28 07:45 PM
回復 #2 Devonian 的帖子

Since we did not analyze their organic remain, we cannot ascertain based on fossil morphology. Despite earlier researchers believed that those fossils are remains of animals,some non-animal single cell colonies or even extinct clade can leave similar fossil traces as well due to factors such as convergent evolution. Nowadays we can confirm dickinsonia is indeed an animal because of certain biochemical, like in this case cholesterol, preserved in the fossil.  Since different clade of organism such as red algae, green algae, and animal use different type of steroid for their body structure, discovery of certain steroid like cholesterol in the fossil can confirm phylogeny relationship between the fossil discovery to modern clades if there relative still exists.
Bear in mind, the discovery only confirm that Dickinsonia is an animal while we cannot extrapolate other creatures such as trilobozoa as an animal unless we conduct similar analysis based on organic molecules found inside the fossils.


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