Crinoid necklace 2 : 無料・フリー素材/写真
Crinoid necklace 2 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | 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.This reconstructed prehistoric necklace is composed of numerous crinoid columnals and partial crinoid stems. The fossils appear to be silicified and are probably Mississippian in age.Classification: Animalia, Echinodermata, Crinoidea |
| 撮影日 | 2024-03-11 08:49:26 |
| 撮影者 | James St. John |
| 撮影地 |