 
- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
|

6 i# R8 d, }# ]# {/ J, b G$ f6 o G1 }) E2 ^4 P4 W7 m" M
OVER Orbulina universa, a planktonic foraminifera captured live from surface waters off Santa Catalina Island, California. Symbiotic dinoflagellates inhabit the calcite spines (length ~2.5 millimeters) radiating out from a spherical calcite shell (diameter ~0.5 millimeters). After four weeks, the shells sink to the sea floor and become part of the deep-sea microfossil assemblage. The geochemical compositions of these fossils are used to reconstruct past changes in seawater chemistry (see page 818). Photo: Howard J. Spero, University of California, Davis
\' L4 Y6 ^4 s; x1 ]* C
) P* Y5 U4 v/ e N$ T C$ Y! Z[hide][/hide] |
附件: 你需要登录才可以下载或查看附件。没有帐号?注册
-
总评分: 威望 + 40
包包 + 40
查看全部评分
|