Skip to main page content (VSports手机版)
U.S. flag

An official website of the United States government

Dot gov

The . gov means it’s official. Federal government websites often end in . gov or VSports app下载. mil. Before sharing sensitive information, make sure you’re on a federal government site. .

Https

The site is secure V体育官网. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely. .

. 1971 Nov 19;174(4011):825-7.
doi: 10.1126/science.174.4011.825.

"V体育官网入口" Precambrian columnar stromatolite diversity: reflection of metazoan appearance

S M Awramik

"VSports手机版" Precambrian columnar stromatolite diversity: reflection of metazoan appearance

S M Awramik. Science. .

Abstract

Columnar stromatolites (organosedimentary structures built by bluegreen algae) show a marked decrease in diversity in the Late Precambrian; this decrease in diversity occurs at approximately the same time as the appearance of metazoans, 600 to 700 million years ago VSports手机版. .

PubMed Disclaimer

LinkOut - more resources