21. Geologic upheaval during the early Cenozoic era formed the state's basin and range physiographic province. 22. Primates are thought to have developed several of their Cenozoic era , when insects became more numerous. 23. The sea covering southern Alabama remained in place during the early part of the Cenozoic era . 24. The eruptions took place in the Cenozoic era . 25. The event marks the end of the Mesozoic Era, and the beginning of the Cenozoic Era . 26. During the early Cenozoic era , the sea began to retreat from Montana for the last time. 27. Alaska remained tectonically active into the Cenozoic era . 28. The ensuing Tertiary period of the Cenozoic era is also missing from the local rock record. 29. It has nearly vertical layers with continual exposure from the Permian period to the Cenozoic era . 30. The Cenozoic Era spanned a length of time from 66 million years ago to the present.
