This is Part 1 of a course series "The Lost World of Hominins" exploring the evolution of hominins (the lineage of bipedal apes that humans are part of) from the earliest members to the rise of Homo sapiens. Part 1 considers the fossil evidence for hominins dating from about 7 to 3 million years ago that existed prior to the appearance of the first members of the genus Homo. Fossil evidence for pre-human species in Africa such as Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus, and the various Australopithecus and Paranthropus species are examined.  Special attention is paid to iconic fossil specimens such as the famous "Lucy" and "Ardi" specimens and their importance in the history of paleoanthropology. Throughout the course fossil evidence is considered in relation to the paleoenvironmental record and various selective pressures that were vital in early hominin evolution.