Precambrian era

Precambrian by Josef Moravec. Original Oil painting 28" x 22" (71cm x 56cm).

* Available for sale to museums and art collectors.
* Contact us: Dinosaur Corporation

Precambrian era: (Pre-Cambrian) is an informal name for the supereon comprising the eons of the geologic timescale that came before the current Phanerozoic eon. It spans from the formation of Earth around 4600 Ma (million years ago) to the evolution of abundant macroscopic hard-shelled animals, which marked the beginning of the Cambrian, the first period of the first era of the Phanerozoic eon, some 542 Ma. It is named after the Roman name for Cymru/Wales - Cambria - where rocks from this age were first studied.
Remarkably little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what little is known has largely been discovered in the past four or five decades. The Precambrian fossil record is poor, and what fossils are present (such as those of stromatolites) are of limited use for biostratigraphic work.[1] Many Precambrian rocks are heavily metamorphosed, obscuring their origins, while others have either been destroyed by erosion, or remain deeply buried beneath Phanerozoic strata.
It is thought that the Earth itself coalesced from material in orbit around the sun roughly 4500 Ma and may have been struck by a very large (Mars-sized) planetesimal shortly after it formed, splitting off material that came together to form the Moon (see Giant impact theory). A stable crust was apparently in place by 4400 Ma, since zircon crystals from Western Australia have been dated at 4404 Ma.
The term Precambrian is somewhat dated, but is still in common use among geologists and paleontologists. It was briefly also called the Cryptozoic eon. It seems likely that it will eventually be replaced by the preferred terms Proterozoic, Archaean, and Hadean, and become a deprecated term.
It is not known when life originated, but carbon in 3800 million year old rocks from islands off western Greenland may be of organic origin. Well-preserved bacteria older than 3460 million years have been found in Western Australia. Probable fossils 100 million years older have been found in the same area. There is a fairly solid record of bacterial life throughout the remainder of the Precambrian.

*

Contact us to obtain permission for commercial usage of this image: Dinosaur Corporation

*

See more Josef Moravec's Dinosaurs & Prehistoric Ice Age Animals Oil Paintings in Dinosaur Exhibits

Copyright Dinosaur Corporation, USA. All rights reserved TM