https://gcmd.earthdata.nasa.gov/kms/concept/c98a4c91-1b1d-464d-8380-497a186db7eb
broader |
|
|||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
change note |
|
|||||||||||
definition | Cambrian Series 2 is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Miaolingian. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower boundary and subdivision into stages. The proposed lower boundary is the first appearance of trilobites which is estimated to be around 521 million years ago. | |||||||||||
narrower |
|
|||||||||||
reference |
|
|||||||||||
type |
|
|||||||||||
in scheme | chronounits original |