Seeds and fruits from Takarkori rockshelter (central Sahara, Libya): morphological and DNA analysis.

Archaeobotanical studies on macro-remains and pollen, carried out within a multidisciplinary research framework, provided information on the past human-environment relationships and on the Holocene landscape evolution of Central Sahara. This has been repetitively obtained by the studies on rockshelters and caves which are widely distributed in this desert region. The site of Takarkori is a large rockshelter with a well preserved stratigraphic series located in the Acacus Mts. (south-western Libya, central Sahara), not far from the Algerian border. It represents an important source of information about the past Saharan environment and the human-plant relationships in that area. The archaeological excavation of this site (<Italian-Libyan Archaeological Mission in the Acacus and Messak> University of Rome “La Sapienza”, www.acacus.it) were carried out from 2003 to 2006 over a surface of ca. 120 square metres and brought to light occupation layers radiocarbon dated between ca. 4500 and 8600 uncal. years bp. It hosts a 1.6 m thick archaeological deposit including structures, fireplaces and 15 burials of women and childs buried near the shelter wall.During the excavation 85 accumulation of plants (called “spot”) were listed and about 50 of them contain only carpological macroremains and will be useful for investigations on wild cereals. All these carpological spot samples were calculated by weight and volume; a preliminary analysis on the content was done. Spot analysis of the most interesting (for content and/or position in the archaeological site) is in progress and preliminary data are available. In the Centre for Ancient DNA Research of the University of Copenhagen, the extraction of ancient DNA was carried out on records from three spot samples. Many were the initial doubts about the preservation of DNA material so old (two of the spot samples are dated 8000 uncal. years bp; one is dated ca. 6000-5500 uncal. years bp) and stored in dry condition, but the excellent state of preservation (most of spikelets were wholly intact) has yet to find well-preserved DNA (only one sample did not work). Most of DNA sequences agree with the identifications made on the basis of morphological analysis.