Quantcast

Latest Precambrian Stories

Oxygen Levels Prior To The Cambrian Explosion May Have Been Enough For Life
2013-10-19 05:00:29

redOrbit Staff & Wire Reports - Your Universe Online An international team of researchers has discovered that the Earth’s oxygen content 2.1 billion years ago was the same as it was during the so-called Cambrian explosion that occurred approximately 542 years ago and resulted in the appearance of most major animal phyla. Given the fact that oxygen and the development of advanced life are inextricably linked, this led the study authors to ponder the sudden emergence of living...

109fe96495c0817eeef9ded1cbca5f751
2010-12-20 06:20:00

Life on Earth began to flourish about 3 billion years ago, possibly when primitive forms developed efficient ways to harness energy from the Sun's light, according to a new study published in the journal Nature on Sunday. Scientists at the Massachusetts Institute of Technology (MIT) built a "genomic fossil" -- a mathematical model that took 1,000 key genes that exist today -- and calculated how they evolved from the very distant past. The collective genome of all life expanded massively...

7df44894a776d787ec19f7098fe9ed111
2010-12-15 05:35:00

Researchers in Britain and Australia have discovered evidence that parts of the open ocean may have experienced a catastrophic global freeze some 700 million years ago, which nearly wiped out life on Earth. The event, dubbed "Snowball Earth", created such turbulent seas that microorganisms barely survived, and created conditions so harsh that most life is believed to have perished, the scientists said. The researchers claim to have found deposits in the remote Flinders Ranges in South...

2010-06-16 21:42:59

Findings released during the annual Goldschmidt Conference at the University of Tennessee, Knoxville How do we begin to understand what early life was like on Earth about 700 million years ago as our planet shifted from an oxygen-free and probably ice-covered realm to the oxygen-rich world that we know today? One geochemist who decodes the early record of life on Earth has found a method featuring a combination of chemical analyses for a significantly clearer picture of this dynamic...

8d22660e62cb986cd856602ffef2f0d61
2010-03-25 10:28:25

In the '80s, Spanish researchers found the first fossils of Cloudina in Spain, a small fossil of tubular appearance and one of the first animals that developed an external skeleton between 550 and 543 million years ago. Now paleontologists from the University of Extremadura have discovered a new species, Cloudina carinata, the fossil of which has preserved its tridimensional shape. "Cloudina carinata is characterized by its elaborate ornamentation and complexity of the shells and tube that...

030243e0fb0406baf279267b037ec8121
2010-02-12 07:46:41

Stratified marine basin sheds new light on early animal evolution, UC Riverside scientists say A research team led by biogeochemists at the University of California, Riverside has developed a detailed and dynamic three-dimensional model of Earth's early ocean chemistry that can significantly advance our understanding of how early animal life evolved on the planet. Working on rock samples from the Doushantuo Formation of South China, one of the oldest fossil beds and long viewed by...

e764dcc605fdfc6b6f29b2fa84fb7d331
2009-07-09 06:00:00

The Earth has experienced many turning points over its 4.5-billion-year history, such as periods of extreme temperature changes, asteroids and the arrival and disappearance of various life forms.  But one of the most monumental events was the Cambrian-era explosion of life some 540 million years ago, when complex, multi-cellular life burst out all over the planet. Scientists point to this critical period as leading to life as we know it today, although its precise causes were not...

3e320b9291574fc8aba4a17378c335e21
2008-11-21 08:15:00

Groove-like tracks on the ocean floor made by giant deep-sea single-celled organisms could lead to new insights into the evolutionary origin of animals, says biologist Mikhail "Misha" Matz from The University of Texas at Austin. Matz and his colleagues recently discovered the grape-sized protists and their complex tracks on the ocean floor near the Bahamas. This is the first time a single-celled organism has been shown to make such animal-like traces. The finding is significant, because...

2008-09-19 03:00:23

By Zhu, Wenbin Zhang, Zhiyong; Shu, Liangshu; Lu, Huafu; Su, Jinbao; Yang, Wei Mafic dykes are observed in the Korla region along the northern Tarim Block, NW China. Our sensitive high-resolution ion microprobe U-Pb zircon ages, the first determined for these dykes, indicate that the mafic dykes were mainly formed at 650-630 Ma, and thus document the youngest known igneous activity associated with rifting in the Tarim Block during the Neoproterozoic. Combined with previous geochronological...


Latest Precambrian Reference Libraries

Geologic Clock With Events And Periods
2012-11-18 19:10:56

The Neoproterozoic is the third of three subdivisions of the Proterozoic Eon (occurring from 1 billion years ago to 542 million years ago). This terminal era of the Proterozoic is itself divided into three sub-periods called the Tonian, Cryogenian, and Ediacaran Periods. The most severe glaciation known in the geologic record occurred during the Cryogenian Period, when ice sheets reached the equator and formed a possible “Snowball Earth.” And the earliest fossils of multi-cellular life...

Geologic Clock With Events And Periods
2012-10-22 14:17:38

The Archean (formerly Archaeozoic) is a geologic eon between the Hadean and Proterozoic eons. The Archean Eon begins at roughly 3.8 billion years ago (Ga) and ends at about 2.5 Ga. But unlike all other geological ages, which are based on stratigraphy, The Archean eon is defined chronometrically. The lower boundary of 3.8 Ga has also not been officially recognized by the International Commission on Stratigraphy. The name Archean is derived from the ancient Greek (Arkhe), meaning...

Volcano_q
2012-06-26 19:51:17

The Hadean is the unofficial geological period of time that lies just before the Archean time period. The Hadean began with the formation of the Earth roughly 4.5 billion years ago (Ga) and ended about 3.8 Ga; the latter date varies according to different sources. Hadean is derived from Hades, Greek for “underworld,” referring to the hellish conditions on the planet at the time. The term was coined in 1972 by geologist Preston Cloud. The period was later classified as the “Priscoan...

More Articles (3 articles) »
Word of the Day
grass-comber
  • A landsman who is making his first voyage at sea; a novice who enters naval service from rural life.
According to the OED, a grass-comber is also 'a sailor's term for one who has been a farm-labourer.'