1. Introduction

Studies of the evolution of hominin cognitive abilities and the origins of intelligence and language focus primarily on stone tool manufacture and on the exploitation of medium-sized to large terrestrial mammals. Here, we examine additional aspects of these cognitive abilities as reflected in a little-known example of skilled behaviour patterns: the exploitation of aquatic flora and fauna in the wetland habitats of paleo-Lake Hula. Although wetlands play an important role in supplementing human diet and enhancing its nutritional balance (Joordens et al. 2009; Wrangham et al. 2009; Cunnane and Steward 2010), few studies have explored the nutritional and/or medicinal properties of wetlands plants in the archaeological context (Stewart 1994; 2010; Colonese et al. 2011; Cortés-Sánchez et al. 2011; Hardy and Moncel 2011; Verhaegen and Munro 2011).

Figure 1: Fox nut (E. ferox) from Gesher Benot Ya'aqov Layer II-6 Level 1, complete seed with its characteristic germination aperture and attachment scar (hilum). (Image credit: authors)

Nuts of the aquatic plant Euryale ferox Salisb. (Nymphaeaceae) (common names: Fox nut, Gorgon nut, Prickly water lily and Makhana in Bihar, India) (Figure 1) were identified in Early to Middle Pleistocene deposits (Marine Isotope Stages 18–20) at the site of Gesher Benot Ya'aqov (GBY), Israel (Goren-Inbar et al. 2000; Feibel 2004; Sharon et al. 2011) (Figure 2). Along with Trapa natans (Water chestnut), they formed part of the botanically rich aquatic habitat of paleo-Lake Hula, comprising over 24 species of water plants (Table 1). Both species are currently extinct in the Levant (Melamed 2003; Melamed et al. 2011). E. ferox and T. natans are floating annual aquatic plants that grow in low-energy or still-water bodies generally around 1.5m deep, occurring within a wetlands ecosystem that was exploited by the GBY Acheulian hominins (Melamed 2003; Ashkenazi et al. 2005; Ashkenazi et al. 2009; Spiro et al. 2009; Mienis and Ashkenazi 2011; Zohar and Biton 2011). The prickly nature of E. ferox renders gathering and processing its nuts far more difficult in comparison with those of T. natans, thus providing us with an opportunity to explore the ways in which this species was exploited at GBY.

Figure 2: Map showing: (A) General view of the location of the regions studied in Israel and India; (B) Location of the Acheulian site of Gesher Benot Ya'aqov, Israel (33°00'30''N, 35°37'30''E) and; (C) Location of water bodies in Madhubani District, Bihar, India where traditional methods of gathering and processing E. ferox are practiced. The water bodies studied are located within a radius of 10km south and east of the town of Madhubani (26°22' 0'' N, 86°5'0'' E). (Image credit: authors)

Here, we present novel evidence for advanced cognitive abilities of Acheulian hominins at GBY as attested by their adoption of complex multistage procedures for collecting and processing E. ferox nuts. E. ferox is widely prevalent in tropical and subtropical regions in ecological contexts similar to those of the paleo-Lake Hula environment. In many such places, it is collected and processed using traditional methods by predominantly freshwater fishing communities (Jha et al. 1991; 2003). The range of these strategies, particularly evident in the water bodies of northern Bihar (Madhubani District, India) (Figure 2), is of immense relevance when examining the archaeological context of E. ferox nut remains at GBY.

The Acheulian site of GBY, situated within the Benot Ya'akov Formation (Belitzky 2002), is located on the shores of paleo-Lake Hula in the Upper Jordan Valley, Dead Sea Rift (Goren-Inbar et al. 2000). This Early to Middle Pleistocene sedimentary sequence documents an oscillating freshwater lake and represents ~100,000 years of hominin occupation (Marine Isotope Stages 18–20) beginning earlier than 790,000 years ago (Feibel 2001; 2004). Studies of the 15 excavated archaeological horizons indicate that Acheulian hominins repeatedly occupied lake margins, produced stone tools, systematically butchered and exploited animals, gathered plant food, and controlled fire (Goren-Inbar et al. 1994; 2002a; 2002b; 2004; Rabinovich et al. 2008; Alperson-Afil et al. 2009).