胎盘菊石
胎盘菊石（学名：Placenticeras），又名平盘菊石、饼菊石，是生存在晚白垩纪海洋中的一属菊石。它们可能是所有已知的菊石中游速最快的，透过喷水的动力来追逐猎物、逃避两栖动物与鱼类的攻击。[2]其化石在亚洲、欧洲和美洲都有发现。[1]
胎盘菊石属 化石时期：白垩纪晚期
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| Placenticeras meeki的化石 | |
科学分类 
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| 界： | 动物界 Animalia |
| 门： | 软体动物门 Mollusca |
| 纲： | 头足纲 Cephalopoda |
| 目： | †菊石目 Ammonitida |
| 科： | †胎盘菊石科 Placenticeratidae |
| 属： | †胎盘菊石属 Placenticeras Meek, 1876[1] |
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特征
胎盘菊石具有紧压的、内旋的壳，腹狭窄，有散发光彩的厚实真珠质层。它们最大可长到50公分长，其巨大的体型和流线型的壳体使它们在水中能快速游动。[2]
物种[1]
- Placenticeras bidorsatum
- Placenticeras cumminsi
- Placenticeras fritschi
- Placenticeras grossouvrei
- Placenticeras kolbajense
- Placenticeras maherndli
- Placenticeras mediasiaticum
- Placenticeras memoriaschloenbachi
- Placenticeras orbignyanum
- Placenticeras paraplanum
- Placenticeras placenta
- Placenticeras polyopsis
- Placenticeras pseudoplacenta
- Placenticeras semiornatum
- Placenticeras syrtale
- Placenticeras tamulicum
- Placenticeras vredenburgi
- Placenticeras whitfieldi
参考文献
- ^ 1.0 1.1 1.2 Fossilworks: Placenticeras. [2018-06-01]. （原始内容存档于2016-03-22） （英语）.
- ^ 2.0 2.1 Walker, Cyril; Ward, David. Fossils. Smithsonian Handbooks revised, illustrated. Dorling Kindersley. 2002: 149. ISBN 0789489848.
- Arkell et al., 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L. Geological Soc. of America, Univ of Kansas Press. R.C. Moore, (Ed)
- W. A. Cobban and Hook, S. C. 1983 Mid-Cretaceous (Turonian) ammonite fauna from Fence Lake area of west-central New Mexico. Memoir 41, New Mexico Bureau of Mines&Mineral Resources, Socorro NM.
- W. A. Cobban and Hook, S. C. 1979, Collignoniceras woollgari wooollgari (Mantell) ammonite fauna from Upper Cretaceous of Western Interior, United States. Memoir 37, New Mexico Bureau of Mines&Mineral Resources, Socorro NM.
- Discovering Fossils: How to Find and Identify Remains of the Prehistoric Past (Fossils & Dinosaurs) by Frank A. Garcia, Donald S. Miller, and Jasper Burns