TIANJIN, July 7 (Xinhuanet) -- Some 1.3 billion years ago, a year had 540 days and 13 to 14 months, a month had 42 days and a day had nearly 15 hours.

　　This is not a sci-fi story but a scientific conclusion made by Chinese geologists after five years of back-breaking study on some fossilized blue-green algae.

　　Dubbed as a "biological clock", blue-green algae varies its growth rhythm in line with the light changes between days and nights, providing valuable evidence of the movement of time during which they live.

　　The algae specimen used in this study were dug out from the stratum of Yanshan Mountain of Jixian County, north China's Tianjin Municipality.

　　Fossilized some 1.3 billion years ago, they have come a long way with floating plates from the equator areas, said Zhu Shixing, a researcher with the Tianjin Geology and Mineral Resources Institute who heads the project.

　　Calling the find an important contribution to global geoscience research, Zhu said the study report had been published in the Journal of Micropaleontology and aroused extensive attention both home and abroad.

　　According to Zhu, over 500 stromatolites containing rich blue-green algae have been extracted from a 3,336-meter-thick massif ofYanshan Mountain since 1998.  Next Page