Oldest evidence of abundant C4 grasses and habitat heterogeneity in eastern Africa

The assembly of Africa’s iconic C4 grassland ecosystems is central to evolutionary interpretations of many mammal lineages, including hominins. C4 grasses are thought to have become ecologically dominant in Africa only after Ma. However, paleobotanical records older than 10 Ma are sparse, limiting assessment of the timing and nature of C4 biomass expansion. This study utilizes a multiproxy design to document vegetation structure from nine Early Miocene mammal site complexes across eastern Africa. Results demonstrate that, between ~21–17 Ma, C4 grasses were locally abundant, contributing to heterogeneous habitats ranging from forests to wooded grasslands. These data push back the oldest evidence of C4 grass5 dominated habitats in Africa – and globally – by more than 10 Myr, calling for revised paleoecological interpretations of mammalian evolution.

Citation

Daniel J. Peppe et al. ,Oldest evidence of abundant C4 grasses and habitat heterogeneity in eastern Africa.Science 380, 173-177 (2023). DOI: 10.1126/science.abq2834

URI

https://hdl.handle.net/1880/119393

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