tribes or nations, associated with particular languages and country. At the time of European contact there were about 600 tribes or nations and 250 distinct languages with various dialects. Aboriginal society was egalitarian with no formal government or chiefs. Authority rested with elders who held extensive ritual knowledge gained over many years. Group decisions were generally made through the consensus of elders. The traditional economy was cooperative, with males generally hunting large game while females gathered local staples such as small animals, shellfish, vegetables, fruits, seeds and nuts. Food was shared within groups and exchanged across groups. Aboriginal groups were semi-nomadic, generally ranging over a specific territory defined by natural features. Members of a group would enter the territory of another group through rights established by marriage and kinship or by invitation for specific purposes such as ceremonies and sharing abundant seasonal foods. As all natural features of the land were created by ancestral beings, a group's particular country provided physical and spiritual nourishment. According to Australian Aboriginal mythology and the animist framework developed in Aboriginal Australia, the Dreaming is a sacred era in which ancestral totemic spirit beings formed The Creation. The Dreaming established the laws and structures of society and the ceremonies performed to ensure continuity of life and land. The extent to which some Aboriginal societies were agricultural is controversial. In the Lake Condah region of western Victoria the inhabitants built elaborate eel and fish traps and hundreds gathered in semi-permanent stone and bark huts during the eel season. However, these groups still moved across their territory several times a year to exploit other seasonal food sources. In semi-arid areas, millet was harvested, stacked and threshed and the seeds stored for later use. In tropical areas the tops of yams were replanted. Flood argues that such practices are better classified as resource management than agriculture and that Aboriginal societies did not develop the systematic cultivation of crops or permanent villages such as existed in the Torres Strait Islands. Elizabeth Williams has called the inhabitants of the more settled regions of the Murray valley "complex hunter gatherers". Early European exploration Dutch discovery and exploration Although a theory of Portuguese discovery in the 1520s exists, it lacks definitive evidence. The Dutch East India Company ship, Duyfken, captained by Willem Janszoon, made the first documented European landing in Australia in 1606. That same year, a Spanish expedition sailing in nearby