Cainozoic
The Cainozoic (Cenozoic) is the present geological era. The word is derived from Greek kainos = "new", and zoe = "life". The era covers the period from 65.5 million years ago to the present. It started after the Cretaceous–Tertiary extinction event, which saw the demise of the last non-avian dinosaurs and the end of the Mesozoic Era.
During the Cainozoic the continents moved into their present positions. The climate started warm, but global cooling continued steadily, and finally ice ages occurred. On land, the Cainozoic is the era of mammals, and of birds and flowering plants. Grassland became a major habitat, and aquatic mammals took over the roles of predatory reptiles like the mosasaurs and plesiosaurs. As a result, the ecological landscape of the Cainozoic has become quite different from the Mesozoic.[1]
Previously, what is now the Cainozoic was divided into two periods, the Tertiary and the Quaternary. The Tertiary coresponded to the Palaeogene+Neogene. Now, the term 'Tertiary' is not used officially.
The Cainozoic is spilt down into three periods, and the periods are split into stages.[2]
- Cainozoic (formerly the Tertiary)
[change] References
- ↑ Levin, Harold L. 2005. The Earth through time. 8th ed, Wiley, N.Y. Chapter 4: The fossil record.
- ↑ International Commission on Stratigraphy [1] There are alternate spellings for some terms: the prefix 'Palaeo' is written 'Paleo' in American English. both versions are correct. 'Cainozoic' may be spelled 'Cenozoic'.
