Eucalyptocrinites fossil crinoid (Massie Shale/Osgood Shale, Silurian; Napoleon, Indiana, USA) 2 : 無料・フリー素材/写真
Eucalyptocrinites fossil crinoid (Massie Shale/Osgood Shale, Silurian; Napoleon, Indiana, USA) 2 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Eucalyptocrinites fossil crinoid from the Silurian of Indiana, USA. (Don Bissett collection)Crinoids (sea lilies) are sessile, benthic, filter-feeding, stalked echinoderms that are relatively common in the marine fossil record. Crinoids are also a living group, but are relatively uncommon in modern oceans. A crinoid is essentially a starfish-on-a-stick. The stick, or stem, is composed of numerous stacked columnals, like small poker chips. Stems and individual columnals are the most commonly encountered crinoid fossils in the field. Intact, fossilized crinoid heads (crowns, calices, cups) are unusual. Why? Upon death, the crinoid body starts disintegrating very rapidly. The soft tissues holding the skeletal pieces together decay and the skeleton falls apart.Classification: Animalia, Echinodermata, Crinoidea, Camerata, Monobathrida, EucalyptocrinitidaeStratigraphy: Massie Shale/Osgood Shale, lower Niagaran Series, upper Llandoverian, Lower SilurianLocality: undisclosed site at or near the town of Napoleon, southeastern Indiana, USA---------------See info. at:en.wikipedia.org/wiki/Crinoid |
| 撮影日 | 2015-05-02 10:48:43 |
| 撮影者 | James St. John |
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