She is a pioneer in the study of the fossil records of terrestrial ecosystems and engages in geological and paleontological field research into the ecological context of human evolution in East Africa.

[2] In 1968, Behrensmeyer made a detailed investigation of Lothagam, a Kenyan paleontological formation dating to the late Miocene-early Pliocene period.

[3] While she was a graduate student at Harvard in 1969, Behrensmeyer was invited by paleoanthropologist Richard Leakey to be his team's geologist and map fossil deposits at Koobi Fora in Kenya.

[4] She discovered a cluster of stone tools eroding out of a volcanic tuff, an ash layer from an ancient eruption that filled a small paleochannel.

Her dissertation, published in 1975, showed that the composition of the fossil vertebrate faunas of East Turkana, Kenya, varied with sedimentary environment (channel, floodplain, lake margin), and this provide new information on the taphonomy and paleoecology of hominin-bearing, Plio-Pleistocene sediments .

The study suggests that fossil animal assemblages in tropical settings can be used to make inferences about ancient habitats when post-depositional taphonomic biases are accounted for.