Fig 1.
Location of sites discussed in text.
A: eastern African coast, showing locations of Pemba and Zanzibar (Unguja) Islands. B: Zanzibar Island, with locations of coring and archaeological sites discussed in the text.
Fig 2.
View of cave looking out from the largest cave chamber. Trench 10 of the 2012 excavation is located just behind the standing figures.
Fig 3.
Kuumbi Cave Trench 10 stratigraphy.
South section drawing based on [44], showing the occupational phases and calibrated dates before present (BP) that are linked to cultural events. See S1 Appendix for details of dating methods and materials, and other dates associated with sedimentary deposition.
Fig 4.
Reconstruction of northern Tanzanian coast 20–6 ka.
Reconstruction at 20 ka, 12 ka, 9 ka, and 6 ka of the topography of the northern Tanzanian coast in meters above Mean Sea Level (MSL) at the time under consideration, with the outline of the present-day coastline. The three largest islands are, from north to south, Pemba, Zanzibar (Unguja), and Mafia. Circles mark coring locations: red, Makoba Bay; green, Unguja Ukuu; blue, Rufiji Delta. The white diamond marks Kuumbi Cave.
Fig 5.
Reconstruction of Zanzibar 20–7 ka.
Reconstruction of the topography of Zanzibar and neighboring Tanzanian mainland in meters above Mean Sea Level (MSL) at the time under consideration, with the outline of the present-day coastline. Circles indicate coring locations: red, Makoba Bay; green, Unguja Ukuu. The white diamond marks Kuumbi Cave. Note that the scale is not identical to that in Fig 4.
Fig 6.
Comparison of model and observational data for relative sea level (RSL).
Comparison of RSL predictions and Holocene RSL observational evidence obtained from sediments on three mangrove sites in Zanzibar and mainland Tanzania [40–42; 61] with occupation timeline of Kuumbi Cave indicated. See Methods for explanation of error margins.
Fig 7.
Bone surface modifications in Kuumbi Cave Trench 10.
Examples of bone surface modifications in the Trench 10 assemblage: a, biochemical pitting from soil or root bacteria; b, shallow, parallel oblique lines indicating sedimentary abrasion; c, micro-notches along the breakage plane, likely produced by a carnivore; d, overlapping cut marks and abrasion on limb bone of duiker; e-f, cut marks on limb bones of reedbuck and bushbuck, respectively.
Fig 8.
Extirpated, extant and introduced fauna in Kuumbi Cave Trench 10.
Relative frequency of nonhuman mammalian fauna that are extant or extirpated on Zanzibar today. “Introduced?” are remains of possible domestic cattle; we stress the tentative nature of this identification, given the paucity of diagnostic elements and the possible persistence of similarly-sized extirpated bovids. Extirpated fauna include: zebra, steenbok, bush duiker, bushbuck, reedbuck, waterbuck, buffalo, white-tailed mongoose, hare, porcupine, and a possible Thomson’s gazelle. Microfauna and remains only identifiable to size class (e.g., “Mammal Size 2”) were excluded from this analysis. NISP, number of identified specimens; MNI, minimum number of individuals.
Fig 9.
Extirpated bovids and equids in Kuumbi Cave Trench 10.
Diachronic trends for extirpated bovids and equids only, with frequencies for these taxa expressed as a percentage of total NISP (number of identified specimens) for all fauna in each phase. For simplicity, tentative identifications to taxon were treated as if they were positive; for example, Cf. T. scriptus and T. scriptus are both listed here as bushbuck. For detailed data, see S1 Table.
Fig 10.
Decline in large mammals in Kuumbi Cave Trench 10.
Diachronic trends in nonhuman mammalian carcass sizes (see Methods), excluding mammals smaller than Size 1 (e.g., rodents, bats, hyrax, mongoose, galago). Some of the medium and large animals in Phase 1 are cattle- and caprine-sized bovids but could not be identified to taxon, and might be either domestic or extirpated taxa. NISP, number of identified specimens; MNI, minimum number of individuals.