Environmental change within the laetoli fossiliferous sequence: Vegetation catenas and bovid ecomorphology

Abstract

Here we investigate changes in Pliocene paleoecological conditions between the Upper Laetolil Beds (3.85–3.63 Ma) and Upper Ndolanya Beds (2.66 Ma) at Laetoli, Tanzania. We assess the ecomorphology (i.e., postcranial adaptations that indicate habitat preferences) of all measureable specimens of the family Bovidae in both beds in order to reconstruct the likely habitat distribution during the deposition of both major geological units. Predicted habitat categories are defined and discussed in terms of extant vegetation associations found in the modern day Laetoli region. Our analyses indicate that the Upper Ndolanya Beds represent a more open environment than was present during deposition of the Upper Laetolil Beds one million years earlier. Additionally, we identify a trend during the 200 kyr deposition of the Upper Laetolil Beds, during which the proportion of woodland, bushland and grass-dominated habitat types shifts throughout the sequence.