what does biological data tell us about ancient environments

environmental indicator faunas

identify associated fossil taxa and their relative abundance

use of modern analogues

basis to reconstruct palaeoecosystems

ecomorphologies

skeletal and dental morphologies that are adaptations to specific niches and habitat types

Laetoli, Tanzania, 2.66 Ma

Study of faunal remains across study sites also with hominin fossils/artefacts. Fossils assessed for body size, locomotor adaptation, and feeding preference. Assemblage compared to a range of modern ecosystems.

MAT

modern analogue technique

MAT use

Compare fossil assemblage (diamonds) with modern samples (circles). Can be used to reconstruct temperature, precipitation, seasonality etc.. Can repeat analysis at multiple different depths to explore how environment has changed over time

triangles

fossil assemblages have no modern analogues

marine sediments

Dust deposited in marine sediment cores can be used to trace arid-humid cycles across Africa over millions of years.

multi-phase drying of SW Africa

Expansion of grasslands from 9-7 million years ago. Followed by a more gradational increase in desert/semi-desert pollen. Long-term aridification trend with forests replaced by grasslands which were themselves partially replaced by desert.

All associated with multi-million year ocean cooling.

Fire activity (high charred particle ratio) peaked with intermediate humidity.