Lureplant/沙盒
地层年代苗嶺世-芙蓉世
Hesslandona angustata,屬於phosphatocopina英语phosphatocopina,化石保存了十分完整的3D結構
类型
属于明礬頁岩層英语Alum Shale Formation
岩性
主要頁岩石灰岩
地点
取名自奧斯坦(Orsten[註 1]
命名克勞斯·穆勒英语Klaus J. Müller,1975
地区Kinnekulle英语Kinnekulle厄蘭島
国家瑞典

奧斯坦型動物群,又稱奧斯坦動物群 The Orsten fauna are fossilized organisms preserved in the Orsten lagerstätte of Cambrian (Late Miaolingian[1] to Furongian) rocks, notably at Kinnekulle and on the island of Öland, all in Sweden.

The initial site, discovered in 1975 by Klaus Müller and his assistants, exceptionally preserves soft-bodied organisms, and their larvae, who are preserved uncompacted in three dimensions. The fossils are phosphatized and silicified, thus the delicate chitinous cuticle and soft parts are not affected by acids, which act upon the limestone nodules within which the fossils have survived. Acids dissolve the limestone, revealing the microfossils in a recovery process called "acid etching". To recover the fossils, more than one and a half tons of Orsten limestone have been dissolved in acid, originally in a specifically designed laboratory in Bonn, more recently moved to Ulm. The insoluble residue is scanned by electron microscope.[2] The phosphorus used to replace the fossils with calcium phosphate is presumed to be derived from fecal pellets.[3]

The Orsten fauna has improved our understanding of metazoan phylogeny and evolution, particularly among the arthropods, thanks in part to unique preservation of larval stages. The Orsten sites reveals the oldest well-documented benthic meiofauna in the fossil record. For the first time, fossils have been found of tardigrades ("water bears") and apparently free-living pentastomids.[4]

The Cambrian strata consist of alum shales with limestone nodules (the Alum Shale Formation), which are interpreted as the products of an oxygen-depleted ("dysoxic")[5] marine bottom water habitat of a possibly offshore seashelf at depths of perhaps 50–100 m.[2] The bottom was rich in organic detritus, forming a soft muddy zone with floc in its surface layer.

Other Orsten-type preservation fauna have been found in Nevada, eastern Canada, England, Poland, Siberia, China and the Northern Territory of Australia.[6]

古生物群

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以下列表係根據於C.O.R.E奧斯坦網站[2]

動物
中文名 屬名 註釋 圖片
球接子屬英语Agnostus Agnostus 屬於球接子目
 
寒武海蜘蛛屬英语Cambropycnogon Cambropycnogon 屬於海蜘蛛目
 
寒武厚槳蝦屬英语Cambropachycope Cambropachycope A monocular arthropod of uncertain affinities, possibly placed in stem-Mandibulata
 
哥特蝦屬英语Goticaris Goticaris A monocular arthropod of uncertain affinities, possibly placed in stem-Mandibulata
 
Rehbachiella A crustacean
 
馬丁遜蟲屬英语Martinssonia Martinssonia A pancrustacean
Dala A pancrustacean
穆薩蝦屬英语Musacaris Musacaris A pancrustacean
Bredocaris A pancrustacean
斯卡拉蟲屬英语Skaracarida Skara A pancrustacean
Sandtorpia A pancrustacean
亨寧斯莫恩蝦屬英语Henningsmoenicaris Henningsmoenicaris A pancrustacean
Walossekia A pancrustacean
Aengapentastomum A pentastomid parasitic crustacean
 
Boeckelericambria
 
Heymonsicambria
 
Haffnericambria
 
Oelandocaris A stem-group crustacean or stem-group mandibulate or megacheiran[7]
 
Hesslandona A bivalved arthropod belonging to Phosphatocopina
Trapezilites
Waldoria
Veldotron
Falites
Vestrogothia
 
奧斯坦小管蟲屬英语Orstenotubulus Orstenotubulus A lobopodian
 

發現於其他地方的奧斯坦型動物群

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Animals
中文名 屬名 註釋 圖片
斯卡拉蟲屬 Skara Two additional species known from Poland and China
Heymonsicambria One additional species known from Ordovician of Canada
Vestrogothia Two additional species known from China
Markuelia A possible member of Cycloneuralia, known from Australia
Shergoldana
Orstenoloricus A loriciferan larva[8] from Australia
Cambrocaris A crustacean, known only from Poland
 
緩步動物門未定種 Unnamed tardigrade Only known from Siberia
 
Wujicaris A pancrustacean known from China
務基蝦屬英语Yicaris Yicaris
 
Dabashanella A member of Phosphatocopina from China
 
Klausmuelleria A member of Phosphatocopina from England
 

註釋

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  1. ^ 奧斯坦原文為"Orsten",意思是「惡臭的石頭」,得名自該地層組富含有機質的明礬頁岩

參考文獻

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  1. ^ Maas, A.; Mayer, G.; Kristensen, R. M.; Waloszek, D. A Cambrian micro-lobopodian and the evolution of arthropod locomotion and reproduction. Chinese Science Bulletin. 2007, 52 (24): 3385. S2CID 83993887. doi:10.1007/s11434-007-0515-3. 
  2. ^ 2.0 2.1 2.2 C.O.R.E. Örsten site
  3. ^ Maeda, Haruyoshi; Tanaka, Gengo; Shimobayashi, Norimasa; Terufumi, Ohno; MATSUOKA, HIROSHIGE. Cambrian Orsten Lagerstätte from the Alum Shale Formation: fecal pellets as a probable source of phosphorous preservation. PALAIOS. 2011-03-30, 26 (3/4): 225–231. JSTOR 25835620. S2CID 131428775. doi:10.2110/palo.2010.p10-042r. 
  4. ^ Modern pentastomids, or "tongue worms" are internal parasites of most modern terrestrial vertebrates.
  5. ^ The distribution of pyrites in the limestone, together with the organic content indicate levels of oxygen that prevented normal decomposition.
  6. ^ Waloszek, Dieter. 'Orsten' on World-Wide Scale. Center of 'Orsten' Research and Exploration. 19 February 2016 [29 November 2016]. 
  7. ^ Aria, Cédric; Caron, Jean-Bernard; Gaines, Robert. Zhang, Xi-Guang , 编. A large new leanchoiliid from the Burgess Shale and the influence of inapplicable states on stem arthropod phylogeny. Palaeontology. 2015, 58 (4): 629–660. S2CID 86443516. doi:10.1111/pala.12161  (英语). 
  8. ^ Peel, John S.; Stein, Martin; Kristensen, Reinhardt Møbjerg. Life Cycle and Morphology of a Cambrian Stem-Lineage Loriciferan. PLOS ONE. 2013-08-09, 8 (8): e73583. ISSN 1932-6203. PMC 3749095 . PMID 23991198. doi:10.1371/journal.pone.0073583 . 

外部連結

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