The Malawi Rift and Pliocene palaeofaunas, which include a hominid mandible attributed to Homo rudolfensis, provide a biogeographical link between the better known Plio-Pleistocene faunal records of East and Southern Africa. The Malawi Rift is in a latitudinal position suitable for recording any hominid and faunal dispersion towards the Equator that was brought on by increased aridity of the Late Pliocene African landscape. The evidence suggests that Pliocene hominids originated in the eastern African tropical domain and dispersed to southern Africa only during more favourable ecological circumstances.

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Mammalian teeth exhibit incremental structures representing successive forming fronts of enamel at varying time scales, including a short daily increment called a cross striation and a long period called a stria of Retzius, the latter of which, in humans, occurs on average every 8–9 days. The number of daily increments between striae is called the repeat interval, which is the same period as that required to form one increment of bone, i.e. the lamella, the fundamental – if not archetypal – unit of bone. Lamellae of known formation time nevertheless vary in width, and thus their measures provide time-calibrated growth rate variability. We measured growth rate variability for as many as 6 years of continuously forming primary incremental lamellar bone from midshaft femur histological sections of sub-Saharan Africans of Bantu origin and known life history. We observed periodic growth rate variability in approximately 6- to 8-week intervals, and in some cases annual rhythms were visible. Endogenous biological periodicities, cycles manifest in the external environment, and/or perturbations of development are all potentially contained within growth rate variability studies of lamellar incremental patterns. Because lamellae are formed within defined periods of time, quantitative measures of widths of individual lamellae provide time-resolved growth rate variability that may reveal rhythms in human bone growth heretofore unknown.

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The vertebrate fauna of the Chiwondo Beds in Northern Malawi is heavily biased towards the preservation of large terrestrial mammals, the majority being ungulates. The faunal diversity resembles an African shortgrass plains assemblage. The taxonomic diversity is nevertheless low, emphasizing an incomplete fossil record. Based on modern bovid representation in African game parks, statistical tests show that the Chiwondo bovid assemblage consists of a mixture of species found in the Somali-Masai and the Zambezian ecozones. The composition of the terrestrial fauna is similar to Swartkrans 1 and the Upper Ndolanya Beds. The fossil assemblages can be assigned to three biostratigraphic time intervals that date from older than 4.0 Ma to less