The South African Stone Age Sequence updated (II)

A decade ago, we summarised the South African and Lesotho Stone Age technocomplex sequence as a heuristic exercise, anchored in 242 dated assemblages (Lombard et al. 2012). Following Clarke (1968), Sampson (1974) and Deacon (1980), we defined a technocomplex as a group of industries characterised by assemblages that have many, but not all, properties in common. Spatiotemporal changes and shifts in artefact design and frequencies owing to material use/availability and socio-economic factors are built into the framework. The accompanying dataset was intended to serve as a useful resource to both students and professionals, and to fuel research and debate.NWOVidi 276-60-004Human Origin

Constraining the likely technological niches of late Middle Pleistocene hominins with Homo naledi as case study

We develop a framework to differentiate the technological niches of co-existing hominin species by reviewing some theoretical biases influential in thinking about techno-behaviours of extinct hominins, such as a teleological bias in discussing technological evolution. We suggest that some stone-tool classification systems underestimate technological variability, while overestimating the complexity of the behaviours most commonly represented. To model the likely technological niches of extinct populations, we combine ecological principles (i.e. competitive exclusion) with physical anthropology and the archaeological record. We test the framework by applying it to the co-existence of Homo naledi and Homo sapiens during the late Middle Pleistocene in southern Africa. Based on our analysis, we suggest that tool use was probably not an essential part of H. naledi’s niche, but that technology occasionally provided caloric benefits. In contrast, tool use was a structural part of the H. sapiens way of life. We provide reasoning for our interpretation that the latter population is associated with more sophisticated reduction strategies and the development of prepared core technology. The method also has applicability to cases such as the co-existence of different toolmakers during the Earlier Stone Age (ESA) in East Africa and the co-existence of Neanderthals and H. sapiens in Eurasia. NWOVidi 276-60-004Human Origin

SDG and E - ERDA Geothermal Loop Experimental Facility. Bi-monthly report, May 1975-August 1976

A description of the Geothermal Loop Experimental Facility (GLEF) its construction problems, and a discussion of start-up testing are included. A history and description of the operation and maintenance with the brine injection pump for the facility are presented. The GLEF was divided into five separate sections: steam and condensate system, brine system, purge water system, vent gas system, and cooling water system. An insight into the chemistry of each system is provided by analysis of samples taken. Scaling and corrosion effects of brine, steam, gas, and water in these systems are described in detail. (MHR

The South African Stone Age Sequence updated (II)

A decade ago, we summarised the South African and Lesotho Stone Age technocomplex sequence as a heuristic exercise, anchored in 242 dated assemblages (Lombard et al. 2012). Following Clarke (1968), Sampson (1974) and Deacon (1980), we defined a technocomplex as a group of industries characterised by assemblages that have many, but not all, properties in common. Spatiotemporal changes and shifts in artefact design and frequencies owing to material use/availability and socio-economic factors are built into the framework. The accompanying dataset was intended to serve as a useful resource to both students and professionals, and to fuel research and debate.</p

Gyrodactylus thlapi n. sp. (Monogenea) from Pseudocrenilabrus philander philander (Weber) (Cichlidae) in the Okavango Delta, Botswana

A new species of Gyrodactylus von Nordmann, 1832 and the first monogenean reported from Botswana is described from the cichlid Pseudocrenilabrus philander philander,bringing the number of gyrodactylids described from the African Continent to 18. Gyrodactylusthlapi n. sp. can be readily discriminated from the other described species almost exclusively by the shape of its hamuli, which have short roots and large, elongate ventral bar attachment points with the dorsal bar attachment point, demarcating the junction between the hamulus shaft and the root, positioned at the anterior terminus of the attachment plane. The marginal hooks of G. thlapi n. sp., which most closely resemble those of G. groschafti Ergens, 1973, are compared and discussed