Museum of Natural History, Tohoku University, Sendai, Japan

TOUR COURSE
"Evolution of Life on Earth"(6)

page 1 / page 2 / page 3 / page 4 / page 5 / Exit

Cenozoic Era

Paleogene / Neogene, Quarternary

Paleogene Period
The Tertiary which began about 65 million years ago is divided into the Paleogene and Neogene Sub-periods. Climate began to cool towards the end of the Paleogene and this trend continues to the present time. Most of the organisms flourished in the Mesozoic are replaced by the rapidly evolving mammals and angiosperm floras. Small-sized ancestral mammals attained a rapid adaptive radiation. The angiosperm flora began to grow lush forests on land and coal measures in Japan were mostly formed during this time interval. In the Paleogene ocean, a group of larger foraminifers called "Nummulites" flourished.

Discocyclina sowerbyi (Foraminifer)
Java, Indonesia
Eocene

(2.5cm across in large body)

Sequoia langsdorfii
Honbetsu Coal-mine, Sorachi, Hokkaido, Japan
Oligocene

(10cm wide)

Sabalites nipponica
Takashima Coal Field, Nagasaki, Japan
Eocene

(42cm long)

Neogene, Quarternary
A geologic time unit of Late Cenozoic age, ranging from 24 million years to 1.8 million years ago, is called the Neogene. The Quarternary Period follows the Neogene and represents the last 1.8 million year's Earth history. Earth climates became cooler during the Neogene and continental glaciers appeared in the Northern Hemisphere. During the last 700 thousand years of the Quarternary, continental glaciers expanded and retreated at about 100 thousand-year intervals. In a glacial time, Europe and North America were covered with thick ice sheets. The last 18 thousand year interval of Quarternary corresponds to the interglacial epoch.

Meimuna protopalifera (Insect)
Kuroiso, Tochigi, Japan
Neogene, Miocene

(3.9cm long)

Cuora miyatai (Amphibian)
Kuzuu, Tochigi, Japan
Quarternary, Pleistocene

(10cm long)

Carcharodon megalodon (Shark's teeth)
Watari, Miyagi, Japan
Neogene, Miocene

(right: 13.5cm long)

Cro-Magnon Race (left) and Modern (right)
Homo sapiens sapiens

Balaenoptera borealis
Recent

(14m long)