Shellmidden Period

The Shellmidden or Shellmound Period is one of the periods of the prehistory of the Okinawa and Amami Islands. It is defined as the period of the prehistory in the Amami and Okinawa Islands with pottery. It lasts from 8000 BCE to the 11th or 12th centuries CE. The culture that develops during this period is called the Shellmidden Culture. It is divided into Early and Late Shellmidden Period, the difference residing in a shift in the settlement location and the development of trade with the neighbouring cultures, first Japan, and then China and Korea.
Economy is mainly based on gathering, fishing and hunting, the principal resources exploited being acorns, fishes and shellfishes. Settlements are limited in size, with the apparition of perennial villages by the end of the Early Shellmidden Period. The material culture is dominated by an important pottery production and very characteristic bone and shell artefacts.
From the 12th century, the Shellmidden Culture is followed by the Gusuku Culture, the first agricultural culture of the Okinawa Islands.
In the Sakishima Islands, the southernmost part of the Ryūkyū Archipelago, the period parallel to the Okinawan Shellmidden Period is called the Sakishima Prehistoric Period. The Amami Islands, the northernmost part of the Ryūkyū Archipelago, first showed strong cultural relation with the Shellmidden Culture, before they shifted and got closer to the Japanese cultural sphere.

Divisions

Shellmidden Period chronologies started being developed by the 1950s. The term of "Shellmidden Period" was introduced by the Okinawa Archaeological Society in 1978.
Tawada Chronology / Current Chronology
The "Current Chronology" is based on the one established by Shinjun Tawada during the 1950s to the 1980s.
The period is called the Shellmidden Period and is divided into Initial Shellmidden Period, Early Shellmidden Period, Middle Shellmidden Period and Late Shellmidden Period. The Initial Shellmidden Period is further divided into Early Phase, Middle Phase and Late Phase.
The Initial Shellmidden Period broadly goes from 8000+ BCE to 2200 BCE, the Early Shellmidden Period goes from 2200 BCE to 1200 BCE, the Middle Shellmidden Period from 1200 BCE to 300 BCE and the Late Shellmidden Period goes from 300 BCE to the 11th-12th centuries CE.
Takamiya Chronology
This chronology, established by Hiroe Takamiya in the 1960s to the 1980s is very widely used by the Okinawan scholars. The term "Shellmidden Period" is sometimes replaced by "Okinawan Neolithic Period". The period is divided into the Early Shellmidden Period and the Late Shellmidden Period. The Late Shellmidden Period is sometimes called the Uruma Period. The Early Shellmidden Period is divided into Phases I to V, the Late Shellmidden Period in Phases I to IV. In recent articles, it is rather divided into two phases than four.
The Early Shellmidden Period Phase I goes from 8000+ BCE to 4300 BCE, Phase II from 4300 BCE to 3200 BCE, Phase III from 3200 BCE to 2200 BCE, Phase IV from 2200 BCE to 1300 BCE, Phase V from 1300 BCE to 300 BCE. The Late Shellmidden Period Phase I goes from 300 BCE to 600 CE; Phase II from 600 CE to 1100 CE.
Okinawa Prefecture Chronology
This chronology was established by the Editorial Committee of Okinawa Prefecture History in 2003. It is broadly based on the divisions established by Takamiya, but uses a Japanese terminology, naming the Early Shellmidden Period the "Jōmon Period" and the Late Shellmidden Period the "Period that is contemporaneous of the Yayoi to Heian Periods". It is mainly used in the publications by the Okinawa Prefectural Archaeological Center and the Prefectural Museum.

Relations between the Shellmidden Culture of Okinawa/Amami and the Jōmon Culture of Japan

There are at least three points of view concerning the relations between the Shellmidden Culture of Okinawa/Amami and the Jōmon Culture of Japan.
The Shellmidden Culture is a sub-culture of the Japanese Jōmon Culture, and the Japanese divisions of the Jōmon Period should be applied.
This point of view used to be defended by, inter alia, Hiroe Takamiya and Isamu Chinen.
Based on the first discoveries of prehistoric pottery in Okinawa, the Shellmidden Period pottery was identified to Jōmon pottery. Takamiya said that the two cultures were identical at least until the phase of the Sobata Type Pottery and then gradually differed from the Early or Middle Jōmon, leading to the creation of an original culture in the Ryūkyū Archipelago. Chinen said that not only the pottery was similar, but also the lithics and bone artefacts. He said that other archaeologists insisted too much on the differences instead of focusing on the similarities.
The Shellmidden Culture and the Jōmon Culture are distinct cultures, focusing on the differences between the two cultures.
This point of view is defended by, inter alia, Shiichi Tōma, Michio Okamura, Naoko Kinoshita or Kensaku Hayashi.
The first three insist on the differences in the spiritual culture, with the absence of dogū ritual statuettes or ritual stone sceptres from sites of the Shellmidden Period in Okinawa, the fact that what is considered as jōmon cultural traits in the Shellmidden Culture, such as pit dwellings, crouched burials of humans and dogs or the burning of houses are in fact traits found in many north-east Asian cultures, while the elements that can only be found in the Jōmon Culture are absent and the fact that the body ornaments are completely different in the two cultures. Hayashi insists on the difference in the way of life, with people of the Jōmon Culture having the habit of digging storage pits to store food, which is a trait that is hardly seen in the Shellmidden Culture.
The Shellmidden Pottery is Jōmon Pottery, but the Shellmidden Culture is not Jōmon Culture, a point of view accepting both the similarities and differences of the two cultures.
This point of view is mainly defended by Shinji Itō.
He says that despite the fact certain particularities can be observed in the shapes, the pottery of the northern part of the Ryūkyū during the Jōmon Period should be called the Ryūkyū Jōmon Pottery, that there is, as far as pottery is concerned, a frontier that can be seen between the Tokara Islands and the Kumage Islands and that the Shellmidden Culture was born from the conjunction of three natural conditions.

Introduction

There are many sites of the Palaeolithic Period in the Okinawa and Sakishima Islands that yielded fossil human remains. There is then an interregnum with no archaeological sites, from 10,000 to 8000 BCE in the Okinawa Islands and from 18,000 to 5000 BCE in the Sakishima Islands. It is not clear if the populations of the Shimotabaru Culture in the Sakishima Islands, or the ones of the Shellmidden Culture in the Okinawa Islands, are related to the previous palaeolithic populations.

Early Shellmidden Period

Since the Shellmidden Period is defined as the period of the prehistory with pottery, its upper limit is regularly pushed earlier with the successive discoveries of older pottery. It is currently placed by 8000 BCE.
The fundamental components of the Shellmidden Culture though, mainly appear during the Early Shellmidden Period Phase III, which is considered as an essential stage for the development of the culture, when the coral reefs reach their maturity.

Livelihood

A great diversity of vegetal resources is used as soon as the beginning of the Early Shellmidden Period: 30 types of different vegetal remains were identified in Aragusuku-shichabaru 2 Site from the Early Shellmidden Period Phase I, 60 types in Ireibaru Site from Phase II or in Mēbaru Site from Phase IV.
The use of acorns is documented as early as the Early Shellmidden Period Phase I in Amami and Phase II in Okinawa, and perdures throughout the period, with an extensive collect of chinquapin beech and Okinawan oak acorns. In Ireibaru and Mēbaru the acorns have been found in bamboo baskets placed in water to wash the tannin before they could be eaten. Sites with physical remains of the ecofacts are scarce, but the extensive presence of hammers, anvils and grinding stones, related to the processing of the acorns on sites from the whole period tells the relative importance of the acorns in the diet. From these tools it seems that the acorns were first cracked opened and then reduced to flour
At the beginning of the Early Shellmidden Period, during Phase I, proteins are essentially obtained through the hunt of wild boars. Bows and arrows are introduced, very probably from Jōmon Japan. Pit traps have also been found. However, by 6000 yBP, as the coral reefs start to appear, the economy begins to shift towards a dependence to marine resources, the percentage of wild boars in the diet decreasing constantly during Phase II and staying very low compared to the marine resources for the rest of the Shellmidden Period. During Phases I and II the coral reefs are not yet very developed and the resources are scarce. Starting from Phase III the marine resources retrieved from the archaeological sites greatly increase, and their variety show that the shallow parts of the coral reefs, easily reached at low tide, are widely exploited. The appearance of artefacts interpreted as fishnet sinkers in Phase III hints at the development of the fishing techniques.

Settlements

The oldest sites in the Early Shellmidden Period are mainly found in caves and on the sand hills by the coast. In the Early Shellmidden Period Phase IV, the sites are rather concentrating more inland in the higher areas, and in the Early Shellmidden Period Phase V, sites present concentrations of pit-dwellings gathered in villages. At the very end of the period, the sites start to shift toward the sand dunes along the coast, that will be their preferred location during the following Late Shellmidden Period.
Most settlements present a combination of smaller and larger dwellings, generally squared with rounded angles. Although most of the identified dwellings are pit-dwellings with a line of small limestone boulders on their periphery, there are also some without the limestone lining, or stone-paved dwellings, not necessarily dug into the ground. All those types are found during the Early Shellmidden Period Phase V and the fine chronology of their appearance is still discussed.