Welmoed A. Out

Microbotanical Evidence of Domestic Cereals in Africa 7000 Years Ago

The study of plant exploitation and early use of cereals in Africa has seen over the years a great input from charred and desiccated macrobotanical remains. This paper presents the results of one of the few examples in Africa of microbotanical analyses. Three grave contexts of phytolith-rich deposits and the dental calculus of 20 individuals were analysed from two Neolithic cemeteries in North and Central Sudan. The radiocarbon-dated phytoliths from the burial samples show the presence of Near East domestic cereals in Northern Sudan at least 7000 years ago. Phytoliths also indicate the exploitation of wild, savannah-adapted millets in Central Sudan between 7500 and 6500 years ago. The calculus samples contained starch grains from wheat/barley, pulses and millets, as well as panicoid phytoliths. This evidence shows that Near East domestic cereals were consumed in Northern Africa at least 500 years earlier than previously thought.

A New Method for Morphometric Analysis of Opal Phytoliths from Plants

Micro-morphometry has substantially gained ground in the field of phytolith analysis, but the comparability of results is limited due to the use of different methods. This paper presents a new, user-friendly method based on open-source software (FIJI) that is proposed as a step towards the introduction of a standard method. After obtaining a mask of a phytolith by making a digital drawing, 27 commonly used variables of size and shape are measured automatically. This method is not only useful for phytolith analysis, but may also be used for other fields of morphometric research. Users can furthermore customize the software tool when additional variables are required.

Morphometric distinction between bilobate phytoliths from Panicum miliaceum and Setaria italica leaves

The development of identification criteria for crop plants based on phytoliths is of high relevance for archaeology, palaeoecology and plant systematics. While identification criteria are available for major food crops, these are mostly based on phytoliths from inflorescences, while other plant parts remain undetected. This paper focuses on bilobate phytoliths from leaves of Panicum miliaceum L. (common millet) and Setaria italica (L.) P. Beauv. (foxtail millet), two taxa that co-occur in regions of Asia and Europe since prehistory and regularly occur at archaeological sites in Eurasia. Leaves of the investigated taxa were systematically sampled to explore the variation of short cells and to collect 27 morphometric variables of bilobate phytoliths with newly developed open-source software. The data was analysed by discriminant analysis, analysis of variance and multiple comparison tests. The resulting morphometric data from five populations per species enables a distinction between the bilobate phytoliths of P. miliaceum and S. italica. Observed differences between populations within species affect only few parameters. This possibility to classify populations of bilobate phytoliths from P. miliaceum and S. italica leaves offers a new method for the detection and identification of these taxa in archaeology, amongst others.

Interpretation of prehistoric reddish pit fillings on Easter Island: A micromorphological perspective

In the context of geoarchaeological investigations on Easter Island several hundred human-made pits filled with reddish silty material were discovered in fluvial terraces of two valleys on the southern slope of Maunga Terevaka, the highest volcano of the island. Micromorphological analysis of one representative pit filling and comparison of its geochemical and physical properties with sediments in the surrounding terrace was performed in order to reconstruct the probable formation and use of the material in the pits. A hypothesis of pigment production by heating of minerogenic iron-rich substrate with grass fuel resulting in formation of hematite is suggested. It is assumed that the pits represented the places for production and storage of the pigments, which were used by Rapa Nui for cultural and ritual purposes. The ongoing interdisciplinary research will enhance the interpretation of the pits and their fillings and contribute to a better understanding of cultural development on Easter Island.