This article presents the methods employed at the site of Lalibela, Ethiopia during the 2009, 2010, 2011 and part of the 2012 campaigns, as well as the first results obtained. This site consists of a group of rock-cut churches attributed to the sovereign of the same name, King Lalibela, who we know to have reigned in the late 12th century and in the first third of the 13th century. Cut out of solid rock, Lalibela is an exceptional archaeological site since most of the traces of its early phases were eliminated in the process of its transformation. The site thus presents a significant challenge for historians and archaeologists. How is it possible to write its history without excavation? Geomorphological observations of the region offer new keys for understanding Lalibela; identification of the spoil heap, in which we discovered a clear stratigraphy confirming the existence of different cutting phases; the topographic and taphonomic analysis of the remains, and investigations in the cemetery of Qedemt, revealed that the site was formed in multiple phases, probably reflecting a long occupation sequence spanning at least eleven centuries (from the 10th to the 21st century).
The StW 573 skeleton of Australopithecus prometheus from Sterkfontein Member 2 is some 93% complete and thus by far the most complete member of that genus yet found. Firmly dated at 3.67 Ma, it is one of the earliest specimens of its genus. A crucial aspect of interpretation of locomotor behaviour from fossil remains is an understanding of the palaeoenvironment in which the individual lived and the manner in which it would have used it. While the value of this ecomorphological approach is largely accepted, it has not been widely used as a stable framework on which to build evolutionary biomechanical interpretations. Here, we collate the available evidence on StW 573’s anatomy in order, as far as currently possible, to reconstruct what might have been this individual’s realized and potential niche. We explore the concept of a common Australopithecus “bauplan” by comparing the morphology and ecological context of StW 573 to that of paenocontemporaneous australopiths including Australopithecus anamensis and KSD-VP-1/1 Australopithecus afarensis. Each was probably substantially arboreal and woodland-dwelling, relying substantially on arboreal resources. We use a hypothesis-driven approach, tested by: virtual experiments, in the case of extinct species; biomechanical analyses of the locomotor behaviour of living great ape species; and analogical experiments with human subjects. From these, we conclude that the habitual locomotor mode of all australopiths was upright bipedalism, whether on the ground or on branches. Some later australopiths such as Australopithecus sediba undoubtedly became more terrestrial, allowing sacrifice of arboreal stability in favour of manual dexterity. Indeed, modern humans retain arboreal climbing skills but have further sacrificed arboreal effectiveness for enhanced ability to sustain striding terrestrial bipedalism over much greater distances. We compare StW 573’s locomotor adaptations to those of living great apes and protohominins, and agree with those earlier observers who suggest that the common panin-hominin last common ancestor was postcranially more like Gorilla than Pan.