使用者:Lureplant/沙盒
| Lureplant/沙盒 地層年代： | |
|---|---|
 Hesslandona angustata，屬於磷足類，化石保存了十分完整的3D結構 | |
| 類型 | 層 |
| 屬於 | 明礬頁岩層 |
| 岩性 | |
| 主要 | 頁岩、石灰岩 |
| 地點 | |
| 取名自 | 奧斯坦（Orsten）[註 1] |
| 命名 | 克勞斯·穆勒，1975 |
| 地區 | Kinnekulle、厄蘭島 |
| 國家 | 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
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 | Agnostus | 屬於球接子目 |  |
| 寒武海蜘蛛屬 | Cambropycnogon | 屬於海蜘蛛目 |  |
| 寒武厚槳蝦屬 | Cambropachycope | A monocular arthropod of uncertain affinities, possibly placed in stem-Mandibulata |  |
| 哥特蝦屬 | Goticaris | A monocular arthropod of uncertain affinities, possibly placed in stem-Mandibulata |  |
| Rehbachiella | 屬於甲殼亞門 |  | |
| 馬丁遜蟲屬 | Martinssonia | 屬於泛甲殼動物 | |
| Dala | 屬於泛甲殼動物 | ||
| 穆薩蝦屬 | Musacaris | 屬於泛甲殼動物 | |
| Bredocaris | 屬於泛甲殼動物 | ||
| 斯卡拉蟲屬 | Skara | 屬於泛甲殼動物 | |
| Sandtorpia | 屬於泛甲殼動物 | ||
| 亨寧斯莫恩蝦屬 | Henningsmoenicaris | 屬於泛甲殼動物 | |
| Walossekia | 屬於泛甲殼動物 | ||
| 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 | Orstenotubulus | A lobopodian |  |
發現於其他地方的奧斯坦型動物群
| 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 |  |
| 務基蝦屬 | Wujicaris | 屬於泛甲殼動物，發現於中國 | |
| 彝蝦屬 | Yicaris |  | |
| Dabashanella | A member of Phosphatocopina from China |  | |
| Klausmuelleria | A member of Phosphatocopina from England |  | |
註釋
- ^ 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
- ^ 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.
- ^ 2.0 2.1 2.2 C.O.R.E. Örsten site
- ^ 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.
- ^ Modern pentastomids, or "tongue worms" are internal parasites of most modern terrestrial vertebrates.
- ^ The distribution of pyrites in the limestone, together with the organic content indicate levels of oxygen that prevented normal decomposition.
- ^ Waloszek, Dieter. 'Orsten' on World-Wide Scale. Center of 'Orsten' Research and Exploration. 19 February 2016 [29 November 2016].
- ^ Aria, Cédric; Caron, Jean-Bernard; Gaines, Robert. Zhang, Xi-Guang , 編. 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
（英語）.
- ^ 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 .
