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Hominid Ichnology: Tracking Our Own Origins

Ichnology is the over-all study of traces made by organisms, including their description, classification, and interpretation (Pemberton et al., 1992). Hominids are our ancestors who are more closely related to us than to any other living species, and they include australopithecines and members of the genus Homo with all species extinct except one: Homo sapiens (Champbell and Reece, 2002). Hence, Hominid Ichnology, a term introduced by Lockley (1998), is literally the ichnology of hominids—the study of traces made by hominids, our ancestors. Traces have been commonly referred to as evidence of the activity of organisms (McIlroy, 2004), work of organisms (ICZN Article 1.2.1, 1999). Traces, activities or work, of hominids are diverse, and may include not only (1) footprints made by walking on substrates but also (2) paintings on the rock surface and sculptures made with shells, bones, antlers, or wood, and (3) diverse tools commonly made with stones (Fig. 1). Fossil skulls, teeth, and bones of humans are not included in the category of hominid traces because they are not the result of human activities (or behavior) but are rather parts of human body itself, that is, body fossils. Hominid footprints made by the hind feet (1), paintings and sculptures (2), and stone and other tools “made by hand” (3) are all diagnostic traces made by hominids, but the list does not end here because any “built structure” can potentially be included in category 3. The study of hominid footprints (1), which belong to vertebrate ichnology, is only a part of hominid ichnology (sensu stricto). Studies of paintings and sculptures (2) and stone tools (3) are also included in hominid ichnology (sensu lato). However, it would be unrewarding and controversial to claim that the study of tools and artwork should be redefined as the exclusive province of hominid ichnology rather than archaeology or anthropology. The reasons for this are many. First, there is the issue of practicality. While paintings, sculptures, and manufactured tools