- During this geological period, many new and anatomically sophisticated creatures appeared suddenly in the sedimentary layers of the geologic column without any evidence of simpler ancestral forms in the earlier layers below, in an event that paleontologists today call the Cambrian explosion.
The Cambrian period is the first period of the Paleozoic era, and is divided into Early, Middle, and Furongian epochs. The Cambrian is preceded by the Precambrian era and followed by the Ordovician era.The Cambrian was named by the geologist Adam Sedgwick for Cambria, Latin for Wales, which has large areas of rock originating in, and characteristic of, the period.Common Cambrian fossils are of trilobites, and inarticulate brachiopods, corals and primitive echinoderms. They also include what are considered by evolutionists to be the first vertebrates, "primitive" jawless fish. Fossil remains other than shells or carapaces are rare. One notable site for soft-bodied Cambrian invertebrate remains is the Burgess Shale of British Columbia.
Era and evolution
Under the uniformitarian dates assigned by secular geologists, it represents approximately the period of Earth's history from about 542 million years ago to 488 million years ago. Young Earth creationists reject the uniformitarian assumptions behind the dates derived by secular geologists, so they reject these dates (see geologic system). Instead, most would consider the Cambrian sediment to be early Flood deposits.
Evolutionists believe that the Cambrian Radiation gave rise to almost all living phyla, but often in extinct forms with small resemblance to typical living species. The rarity of shells or carapaces leads evolutionists to conclude that many of the organisms of the time were soft-bodied invertebrates.
- Agassiz concluded that the fossil record, particularly the record of the explosion of Cambrian animal life, posed an insuperable difficulty for Darwin's theory. Darwin's Doubt, page 8 - Stephen C. Meyer
- Darwin's Doubt, page 7 - Stephen C. Meyer
- Gradstein, F.M., and Ogg, J.G.,Geologic Time Scale 2004 – Why, How, and Where Next!
- Snelling, Andrew, Radiohalos in Granite, chapter 5 of DeYoung, Don, "Thousands, Not Billions", Master Books, 2005, p.89, ISBN 0-89051-441-0.