- adjkjc.github.io en.wikipedia.org/wiki/…The Cambrian is divided into several regional faunal stages of which the Russian-Kazakhian system is most used in international parlance
- meteorologiaenred.com en/Cambrian.htmlThat is, no land pole was covered with ice. In turn, the Cambrian period is divided into three eras: Lower Cambrian, Middle Cambrian and Upper Cambrian.
- geologypage.com Geologic time scale Cambrian PeriodThe Cambrian is the first geological period of the Paleozoic Era, lasting from 541.0 ± 1.0 to 485.4 ± 1.9 million years ago (mya) and is succeeded by the Ordovician.
- wildlifewonders.pages.dev posts/what-is-the-…The term Cambrian explosion refers to a short period in geologic history characterized by the emergence of many new and diverse organisms.
- ucmp.berkeley.edu cambrian/cambrian.phpA few mineralized animal fossils, including sponge spicules and probable worm tubes, are known from the Ediacaran Period immediately preceding the Cambrian.
- http://scotese.com newpage12.htmCambrian: the beginning of the Paleozoic Era. ... Animals with hard-shells appeared in great numbers for the first time during the Cambrian.
- britannica.com Fossils & Geologic TimeCambrian Period, earliest time division of the Paleozoic Era and Phanerozoic Eon, lasting from 538.8 million to 485.4 million years ago.
- aayushianshu1625.medium.com cambrian-explosion-…Since Cambrian times earth had seen a diversity like never before but what about before Cambrian? If we go back in time, earth formed around 4.5 billion years ago.
- nationalgeographic.com science/article/cambrianThe Cambrian period, part of the Paleozoic era, produced the most intense burst of evolution ever known.