41. The Paleocene and the Eocene epochs are found in the Cenozoic Era , or the age of the mammals. 42. This time, called the Cenozoic Era , is when the area began to look much like it does today. 43. The ensuing Paleogene and Neogene periods of the Cenozoic era is also missing from the state's rock record. 44. The ` alek Valley formed in the late Cenozoic era , during the Pliocene epoch of the Neogene period. 45. This was followed by late Mesozoic and Cenozoic subsidence creating the submarine topography occurred in the Cenozoic era . 46. Ammonite fossils became less abundant during the latter part of the Mesozoic, with none surviving into the Cenozoic era . 47. The simian line and the tarsier line diverged about 60 million years ago ( during the Cenozoic era ). 48. The last eruption from Suiko Seamount occurred 60 million years ago, during the Paleogene Period of the Cenozoic Era . 49. Sedimentary rocks from the late Mesozoic era and early Cenozoic era are found in the western part of the region. 50. It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed.