Cambrian period


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Cambrian period

The first part of the Paleozoic era: 590 to 505 million years ago.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.Cambrian period - from 544 million to about 500 million years ago; marine invertebrates
Paleozoic, Paleozoic era - from 544 million to about 230 million years ago
References in periodicals archive ?
Our results show the ancestor of land plants was alive in the middle Cambrian Period, which was similar to the age for the first known terrestrial animals.
We have proved that this happened in the middle of the Cambrian period, at the time when the first terrestrial animals appeared, "says Jennifer Morris of Bristol University.
It was also believed to have lived during the middle Cambrian period 508 million years ago, hence its age, and was from the renowned Burgess Shale fossil deposit in British Columbia.
The search for fossils from such ancient times, 60 million years before the Cambrian period and its burst of multicellular evolution, has yielded tantalizing bits but nothing with details like this specimen.
The prior oldest known primitive sponge fossil only dated to 530 million years ago, in early Cambrian period.
Although the evolutionary origins of fish and fishlike animals can be traced all the way back to the Cambrian Period (about 515 million years ago), those earliest primitive vertebrates were soft-bodied and lacked many of the features (including scales, bony bits, and jaws) that characterize the later fossil record.
To say that the fauna of the Cambrian period appeared in a geologically sudden manner also implies the absence of clear transitional intermediates connecting the complex Cambrian animals with those simpler living forms found in lower strata.
Fossilized records from the Cambrian Period, which occurred between 540 million and 485 million years ago, provide glimpses into evolutionary biology when the world's ecosystems rapidly changed and diversified.
The evolutionary trend that led from large, apex predators to gentle, suspension-feeding giants during the highly productive Cambrian period is one that has also taken place several other times throughout Earth's history, according to lead author Dr Jakob Vinther, a lecturer in macroevolution at the University of Bristol.
Dozens of individual theories have been put forward over the past few decades for this rapid diversification of animal species in the early Cambrian Period of geological time.
The Cephalopod class, including squid, octopus and cuttlefish, a) is neurologically advanced, b) the same organ serves multiple functions, c) some mollusks contain pearls, purple dye and shells that humans value; and d) the Cephalopod class dates back to the Cambrian period 541 to 485 years ago.
Similarly, at the beginning of the Cambrian period, the author notes the emergence of another familiar aspect of the human race: consumer society.