Serengeti micromammal communities and the paleoecology of laetoli, Tanzania

Abstract

The fossil deposits at Laetoli provide critical paleoanthropological insights that can be better understood in light of the modern Serengeti ecosystem. Earlier paleoenvironmental reconstructions of the site depicted it as a semi-arid grassland, similar to the modern Serengeti plains. Subsequent analyses, however, have converged around an interpretation emphasizing a greater wooded component in a more humid climate, suggesting that the adaptations of A. afarensis remain linked to a more closed and wooded biome. The range of proposed paleoenvironments encompasses the range seen in the modern Serengeti-Masai Mara ecosystem today and thus the Serengeti serves as a natural analogy for comparisons with Laetoli. Our understanding of past environments is informed by the study of modern mammalian communities where it is possible to observe species distributions, adaptations and community composition. As paleoenvironmental indicators, micromammals provide a signal of local paleoenvironments at a smaller spatial grain than large mammals and thus may prove critical to resolving some of the ambiguities of paleoenvironmental interpretations at Laetoli. This chapter presents findings on the modern rodent biodiversity in Serengeti based on material recovered from owl roosting sites distributed throughout the ecosystem. The Serengeti experiences strong ecological gradients, which influence vegetation patterns and the distribution of rodent genera. Examining the interplay between habitats and rodent community composition provides the necessary baseline perspective for interpreting Laetoli paleoenvironments.