Japanese History Digest

Paleolithic Age

The Origin of Humankind

The origins of humanity are currently believed to date back approximately seven million years to Africa. Early hominins from this period, such as Sahelanthropus, are thought to have possessed the rudimentary characteristics of upright bipedalism. Following further evolution, the genus Homo (including Homo habilis) emerged around 2.5 million years ago and began using stone tools. Subsequently, approximately 300,000 years ago, anatomically modern humans (Homo sapiens) emerged in Africa, later dispersing into Eurasia, Oceania, and the Americas.

The Japanese archipelago originally formed as the coastal fringe of the Eurasian continent. Through tens of millions of years of plate tectonic activity, it gradually took on its current arc-like shape. The prototype of the archipelago, including the Sea of Japan, was established during the Cenozoic era. Throughout the Pleistocene (approx. 2.58 million to 11,700 years ago), the islands repeatedly connected to and separated from the mainland as sea levels fluctuated during alternating glacial and interglacial periods. During glacial peaks, lower sea levels created land bridges between the Japanese archipelago and the Asian continent, allowing large mammals to migrate from the directions of Siberia and mainland China.

As the last glacial period ended more than 10,000 years ago and the climate warmed, sea levels rose, transforming the archipelago into the chain of islands we recognize today. This transition set the stage for the subsequent Jomon period.

In this manner, humanity originated in Africa and spread across the globe through a long process of evolution and migration. The Japanese archipelago also shifted its form throughout geological time, eventually becoming a place where humans settled and fostered a unique, independent culture.

 

The Paleolithic Period in Japan

Chronology and Climate
The Paleolithic period in Japan corresponds to the Pleistocene epoch in geological terms—the "Ice Age" that lasted from approximately 2.58 million to 11,700 years ago. However, definitive traces of human activity in the archipelago are primarily found from the Upper Paleolithic period onward (approx. 40,000 years ago).

This era is categorized as a Pre-Ceramic culture, continuing until about 12,000 years ago when the Jomon period began with the emergence of pottery. During glacial peaks, lower sea levels occasionally created land bridges connecting the Japanese archipelago to the Asian mainland. This allowed cold-adapted fauna, such as mammoths and giant elk (Sinomegaceros yabei), to migrate from the north, while Naumann’s elephants expanded their habitat mainly into central and western Japan. It is believed that early humans followed these large and medium-sized animals or migrated in search of other natural resources.

Tools and Technology
The Paleolithic people of Japan crafted chipped stone tools from materials such as obsidian, sanukite, and chert.
Early Stage: Large percussion tools like hand-axes and hammerstones were commonly used for striking and crushing.
Later Evolution: Tools became increasingly specialized and diverse. This included knife-shaped tools, points (spearheads) for hunting, and microliths (or microblades)—tiny stone blades designed to be embedded into wooden or bone handles to create composite tools.

Economy and Lifestyle
The economy was fundamentally a hunter-gatherer-fisher system. People relied on hunting animals like deer and wild boar, fishing in rivers and coastal waters, and gathering plant-based foods such as nuts and wild vegetables.
Regarding their dwellings:
Mobility: Life was characterized by high mobility. People often established temporary camps in caves or rock shelters.
Structures: While there are archaeological examples of simple huts or shallow, pit-like structures on flat plateaus or terraces, long-term sedentary living was not yet the norm.
Transition: Full-scale pit-dwellings (tateana jukyo) only became widespread during the early Jomon period in the Holocene. Paleolithic life remained largely nomadic, following the seasonal migration of game and the availability of plants.

Summary
In essence, the Japanese Paleolithic was an era defined by the arrival of humans during the Ice Age and their adaptation to a hunting-gathering lifestyle using sophisticated chipped stone tools. The shift toward agriculture, permanent settlement, and the widespread use of pit-dwellings would only truly take shape in the subsequent Jomon period.

 

Iwajuku Site (Gunma Prefecture)

In 1946, Tadahiro Aizawa discovered chipped stone tools in the red soil exposed in a road cut in Midori City, Gunma Prefecture (formerly Iwajuku, Kasakake Town), known as the Kanto Loam.

At the time, the prevailing view was that no Paleolithic culture existed in the Japanese archipelago prior to the Jomon period. However, this discovery significantly challenged this view of Japan's prehistory.

In 1949, a full-scale excavation survey was conducted by the Meiji University Archaeology Laboratory and others. A group of stone tools without pottery was unearthed in the Kanto Loam, providing academic proof that the Japanese archipelago also had a Paleolithic period. Following this excavation, Paleolithic site investigations expanded throughout Japan, and Paleolithic research developed into a major field in Japanese archaeology.

Excavations at the Iwajuku Site identified two stone tool culture layers, an upper and lower.​
​A group of stone tools dating back approximately 35,000 years ago, known as the Iwajuku 1st Stone Tool Culture, was excavated from the lower layer. These tools display a tool composition characteristic of the early Late Paleolithic, including knife-shaped stone tools with processed bases and partially ground stone axes.
​A group of stone tools dating back approximately 25,000 years ago, known as the Iwajuku 2nd Stone Tool Culture, was discovered in the upper layer. These tools, including cut-out knife-shaped stone tools, are considered a culture from the latter half of the Late Paleolithic.
​The existence of these two cultural layers provides important evidence that the Paleolithic culture of the Japanese archipelago spanned a certain period of time, and that tool composition and technology underwent repeated changes.
​The discovery and investigation of the Iwajuku site has pushed human history in Japan back to the Paleolithic period, long before the Jomon period, and is regarded as a milestone in the history of Japanese archaeology.
Due to this significance, the Iwajuku Ruins were designated a National Historic Site in 1979, and are an essential site for understanding the existence of the Paleolithic period in the Japanese archipelago and the origins of Japanese culture. The Iwajuku Ruins were first discovered in 1946, and excavations were carried out in 1949 in collaboration with Meiji University.
Currently, the Iwajuku Ruins are located in Iwajuku, Midori City, Gunma Prefecture, and a museum and park have been developed in the surrounding area, making it a hub for Paleolithic research and historical learning.

 

Facilities where you can learn about the Paleolithic Age

Official Aizawa Tadahiro Memorial Museum Website
https://www.aizawa-tadahiro.com/

Midori City Iwajuku Museum
https://www.city.midori.gunma.jp/iwajuku/

Sendai City Tomizawa Site Preservation Museum, Forest Museum of Underground
https://www.sentabi.jp/guidebook/attractions/15/

Miyako City Sakiyama Shell Mound Jomon Forest Museum (Miyako City, Iwate Prefecture)
https://www.city.miyako.iwate.jp/gyosei/soshiki/bunka/1/1/1153/index.html

Sendai City Tomizawa Ruins Preservation Center Underground Forest Museum
https://www.sentabi.jp/guidebook/attractions/15/

Lake Nojiri Naumann's Elephant Museum
https://nojiriko-museum.com/

Minamimaki Village Museum of Art and Folklore
http://www.ytg.janis.or.jp/~bijyutsu/

Suichouen Ruins
https://www.city.habikino.lg.jp/soshiki/shichou/toshimiryoku/miryokuhakken/habikinomiryokuhakken/16305.html

Okinawa Prefectural Museum and Art Museum
https://okimu.jp/museum/permanent/specialized/

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