As has been amply shown, the scientific curiosity about ‘exotic’ people in biological anthropology has partly been motivated by their supposed status as ‘living fossils’. Racial hierarchies established by anthropologists drew on phylogenetic theories of how today’s people relate to each other. However, while this has become common knowledge, the actual practices associated with these conceptions have not received sufficient attention. In my paper, I will show how such theoretical assumptions were an outcome of and structured the activities of collecting and analysis. In the early 20th century, collection practices of anthropological institutions brought together fossils from early- and pre-humans, prehistoric skeletons, as well as human remains from extant ‘primitive races’ from all around the globe. These different types of remains were part of a common data set for the development and testing of theories of human origin and human diversity. Fossils and non-fossils were differentiated with regard to age and diagenetic processes, but not regarding scientific theorising. Human ‘living fossils’ were made into epistemic objects for theorising on human phylogeny and diversity to the same extent as fossils sensu stricto. In my paper, I will develop this conclusion for the example of the anthropological collections of the Natural History Museum in Basel, Switzerland, from 1905 to 1918. In the case of the Basel museum it can be shown how the ‘pygmy hypothesis’, i.e. the theory that today’s humans descended from a small-statured ‘race’, fuelled anthropological research. Already equipped with the general notion that ‘primitive’ peoples are living fossils, on their expeditions, Fritz and Paul Sarasin, two anthropologists from Basel, attempted to verify the ‘pygmy hypothesis’. In this endeavour, the Veddahs of Sri Lanka and the Toála of Sulawesi caught their particular attention. Both were small-statured peoples the Sarasins perceived as ‘primitive’ culturally as well as biologically. They conceived of them as the remnants of an ancestral ‘pygmy race’. I will analyse the process of constitution of this supposed ancestral human form to bring to light the interpenetration of the practices of collecting and the studying of collections with notions about human history and diversity.