Early Cretaceous
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| System | Series | Stage | Age (Ma) | |
|---|---|---|---|---|
| Paleogene | Paleocene | Danian | younger | |
| Cretaceous | Upper | Maastrichtian | 65.5–70.6 | |
| Campanian | 70.6–83.5 | |||
| Santonian | 83.5–85.8 | |||
| Coniacian | 85.8–89.3 | |||
| Turonian | 89.3–93.5 | |||
| Cenomanian | 93.5–99.6 | |||
| Lower | Albian | 99.6–112.0 | ||
| Aptian | 112.0–125.0 | |||
| Barremian | 125.0–130.0 | |||
| Hauterivian | 130.0–136.4 | |||
| Valanginian | 136.4–140.2 | |||
| Berriasian | 140.2–145.5 | |||
| Jurassic | Upper | Tithonian | older | |
| Subdivision of the Cretaceous system according to the IUGS, as of July 2009. | ||||
The Early Cretaceous (geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 146 Ma to 100 Ma.
During this time many new types of dinosaurs appeared or came into prominence, including Psittacosaurus, spinosaurids and coelurosaurs, while other survivors from the Late Jurassic continued.
In the seas, the ichthyosaurs declined and eventually died out at the start of the Late Cretaceous. Angiosperms[1] and Eutherians[2] appear for the first time.
[edit] References
- ^ Sun, G., Q. Ji, D.L. Dilcher, S. Zheng, K.C. Nixon & X. Wang 2002. Archaefructaceae, a New Basal Angiosperm Family. Science 296(5569): 899–904.
- ^ Ji, Q., Luo, Z-X., Yuan, C-X.,Wible, J.R., Zhang, J-P.,and Georgi, J.A. (April 2002). "The earliest known eutherian mammal". Nature 416 (6883): 816–822. doi:10.1038/416816a. PMID 11976675. http://www.nature.com/nature/journal/v416/n6883/full/416816a.html. Retrieved 2008-09-24.
[edit] See also
| Cretaceous Period | |
|---|---|
| Lower/Early Cretaceous | Upper/Late Cretaceous |
| Berriasian | Valanginian | Hauterivian Barremian | Aptian | Albian |
Cenomanian | Turonian | Coniacian Santonian | Campanian | Maastrichtian |
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