File:Tentaculite in Devonian limestone (48873661118).jpg
![File:Tentaculite in Devonian limestone (48873661118).jpg](http://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Tentaculite_in_Devonian_limestone_%2848873661118%29.jpg/800px-Tentaculite_in_Devonian_limestone_%2848873661118%29.jpg)
原始文件 (1,871 × 1,006像素,文件大小:1.86 MB,MIME类型:image/jpeg)
摘要
描述Tentaculite in Devonian limestone (48873661118).jpg |
Tentaculites are problematic fossils - their high-level taxonomic placement is uncertain, but they may be molluscs. Tentaculite fossils consist of small to very small calcitic shells. The shells are straight to slightly curving and are slightly tapering tubes. The pointed end of the shell is closed. In some forms, the pointed end is slightly bulbous, with an apical spine (usually broken off). Externally, tentaculite shells usually have ringed ornament and thin, delicate, longitudinal striations. The tip of the shell is the embryonic part. After that is the juvenile portion of the shell, which consists of internal septa, or walls that divide the shell into chambers. Septa have no external expression and number 5 to 20 in one specimen. The adult portion of the shell is nonseptate - it is referred to as the living chamber, which occupies more than half the entire length of the shell. No aperture-like structure has ever been found at the distal end of the shell. The soft-part morphology of tentaculites is poorly known. X-ray images of specimens from the Lower Devonian of Germany seem to show multiple "tentacles" protruding from the large end of the shell. Muscle impressions on the interior have been reported in some tentaculites. Tentaculites are entirely extinct - their geologic range depends on how inclusive the term "tentaculite" is. Tentaculites first definitely appear in Ordovician rocks. Their maximum abundance and diversity was during the Devonian. Tentaculites were entirely marine. They are known from shallow and deep-water deposits. Larger, thick-shelled forms are local in their distribution, and so appear to have been benthic. Smaller, thin-shelled forms have world-wide distributions, and so appear to have been planktonic. Planktonic forms, such as the styliolinids, may not be tentaculites at all. Sometimes, encrusters are found on tentaculite shells. The distribution of encrusting organisms suggests that benthic tentaculites had the apex of the shell pointed downward and the aperture was upward during life. Almost all tentaculite fossils are found parallel to bedding. Very few have been found with the pointed end of the shell vertically inserted into the sediments. Classification: Animalia incertae sedis, Tentaculita, Tentaculitida, Tentaculitidae Locality: building stone at Marion Depot, Marion, Ohio, USA |
日期 | |
来源 | Tentaculite in Devonian limestone |
作者 | James St. John |
许可协议
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这幅图片原始出处为Flickr的https://flickr.com/photos/47445767@N05/48873661118 ,作者为James St. John 。经机器人FlickreviewR 2在2019年12月7日审查后确定为采用cc-by-2.0的协议授权使用。 |
2019年12月7日
说明
此文件中描述的项目
描绘内容
某些值没有维基数据项目
14 9 2019
0.01666666666666666666 秒
10
9.681 毫米
80
image/jpeg
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日期/时间 | 缩略图 | 大小 | 用户 | 备注 | |
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当前 | 2019年12月7日 (六) 19:10 | ![]() | 1,871 × 1,006(1.86 MB) | Ser Amantio di Nicolao | Transferred from Flickr via #flickr2commons |
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元数据
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相机制造商 | Canon |
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相机型号 | Canon PowerShot D10 |
曝光时间 | 1/60秒(0.016666666666667) |
光圈值 | f/10 |
感光度(ISO) | 80 |
数据生成日期时间 | 2019年9月14日 (六) 12:42 |
镜头焦距 | 9.681毫米 |
宽度 | 4,000 px |
高度 | 3,000 px |
每色彩组分位数 |
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像素构成 | RGB |
方向 | 正常 |
色彩组分数 | 3 |
水平分辨率 | 180 dpi |
垂直分辨率 | 180 dpi |
使用软件 | Adobe Photoshop Elements 16.0 (Macintosh) |
文件修改日期时间 | 2019年10月10日 (四) 02:52 |
亮度(Y)和色度(C)位置 | 重叠 |
Exif版本 | 2.21 |
数字化日期时间 | 2019年9月14日 (六) 12:42 |
每个色彩组分意义 |
|
图像压缩模式 | 3 |
APEX快门速度 | 5.90625 |
APEX光圈 | 6.65625 |
APEX曝光补偿 | −0.66666666666667 |
最大光圈 | 3.625 APEX(f/3.51) |
测光模式 | 多区 |
闪光灯 | 闪光灯点亮、闪光灯强制开启、防红眼模式 |
支持的Flashpix版本 | 1 |
色彩空间 | sRGB |
焦平面X分辨率 | 16,460.905349794 |
焦平面Y分辨率 | 16,483.516483516 |
焦平面分辨率单位 | 英寸 |
感光方法 | 单芯片彩色区域传感器 |
文件来源 | 数码相机 |
自订图像处理 | 普通处理 |
曝光模式 | 手动曝光 |
白平衡 | 自动白平衡 |
数字变焦比率 | 1 |
场景拍摄类型 | 人像 |
使用的镜头 | 6.2-18.6 mm |
元数据最后修改日期 | 2019年10月9日 (三) 22:52 |
原始文件唯一ID | 618FA6612BDC9B31AA1B07AC8CFAC821 |