Constellaria florida (fossil bryozoans) (Fairview Formation, Upper Ordovician; Campbell County, Kentucky, USA) : 無料・フリー素材/写真
Constellaria florida (fossil bryozoans) (Fairview Formation, Upper Ordovician; Campbell County, Kentucky, USA) / 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 | Constellaria florida Ulrich, 1882 - fossil bryozoans in limestone from the Ordovician of Kentucky, USA.These bryozoan colonies are from the famous Cincinnatian Series of the tristate area of Ohio-Kentucky-Indiana. The region has some of the richest fossiliferous rocks on Earth. Cincinnatian rocks were deposited in relatively shallow marine facies during the Late Ordovician. The Cincinnatian succession consists of interbedded limestones and shales. Most of the limestones are event beds (= tempestites), deposited during ancient storms.Bryozoans are colonial lophophorates, most of which make a calcareous skeleton. Many bryozoan skeletons have complex shapes that usually cannot be fully appreciated from the fossil record. Bryozoans are abundant fossils, especially in Paleozoic and Mesozoic limestones, but their skeletons usually get busted up during the storm events resulting in their final burial. Colony reconstructions (see elsewhere in this photo album) can be time-consuming, especially with large fragmented specimens.Numerous tiny pits cover bryozoan skeletons. The pits are zooecia - each zooecium housed an individual bryozoan animal, called a zooid. Zooids have a ring of tentacles that filter the water for tiny particles of food. All bryozoans are sessile, benthic filter-feeders.Constellaria is distinctive in having star-shaped mounds (stellate monticules) on the colony surface (click once or twice on the photo to zoom in).Classification: Animalia, Lophophorata, Bryozoa, Stenolaemata, Cystoporida, ConstellariidaeStratigraphy: Fairview Formation, lower Maysvillian Stage, middle Cincinnatian Series, Upper OrdovicianLocality: undisclosed site in Campbell County, northern Kentucky, USA |
| 撮影日 | 2025-04-06 08:45:38 |
| 撮影者 | James St. John |
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