Muddling through the muddle in the middle

Who were our ancestors roaming East-Africa 1.4 to 0.5 million years ago? What did their environment look like and whom did they share it with? How did they cope with increasing aridity and how did this shape their evolutionary trajectory and eventual dispersals out of Africa?

These are some of the key questions investigated by the ERC project Ng’ipalajem (meaning ‘ancestors’ in Turkana), directed by Prof Marta Mirazón Lahr. We were fortunate enough to spend our summer walking in the footsteps of these early pioneers, in a landscape scattered with fossils - evidence of past ecosystems and the lives it supported. 

The region surrounding Lake Turkana in north-western Kenya is renowned for contributing many key fossils to the sparse hominin record. Our work focuses on the area to the southwest of the lake, along the Lower Kerio Valley. This valley is nestled between the Loiru Range, the Napudets, and the Katigathigira Hills, and follows the seasonally active Kerio River, which descends from the Amsya Hills along the central rift. In this tectonically active setting, interactions among the rift system, the river, and the fluctuating levels of the endorheic Lake Turkana have produced a succession of geological formations and fossil-rich deposits that span the Middle Pleistocene through to the early Holocene African Humid Period (AHP). It is this dynamic landscape that provided the centre stage for our fieldwork season.

Our day began at sunrise with the familiar exchange of “Habari?” (How are you?) and instantly “Mzuri” (Good), over a breakfast of freshly baked bread prepared by ‘the Josephs’ (our fabulous kitchen team).

We then armed ourselves with litres of maaji (water), electrolytes and a thick layer of sunscreen.

After heckling over favourite geological hammers which were often “borrowed” by other teams, and a quick decision about whether our tents needed rain covers, we set out for our respective stations at 7am.

It is often said that the best discoveries happen on the last day of a field season. This proved true for the GeoTeam who, while digging their final trench for an OSL sample, uncovered the zygomatic process of a potential Euthecodon crocodile. Suspecting a complete skull, Prof. Mirazón Lahr and Justus Erus Edung (NMK) led an excavation.

Out came the buckets, trowels, brushes, sieves, toilet paper, and plaster. In record time, a nearly complete Euthecodon skull emerged - only the second ever found in Turkana! After protecting it with a jacket of plaster of paris and hessian, it was securely lifted and loaded onto the lorry for processing at TBI.

Covered in dust and sweat, we returned to camp triumphant. Music, dancing, and a feast hosted by the Turkana community awaited us. When we packed camp the following day, we left no trace of past activity behind. It was as if no one had lived there (until future archaeologists discover we did and had a penchant for choma (goat)!). 

Meals became a natural gathering point to discuss the day’s progress and exchange ideas with visiting scholars. The dining area itself carried a sense of history: framed Nature covers on the walls serve as a vivid reminder of the rich legacy of discovery (mostly by a member of the Leakey family!) rooted at TBI.

The picturesque view of acacia trees silhouetted along the Turkwell River provided the perfect setting for conversation. While Elijah, Elipam and Musa worked their magic in the kitchen, lively debates often arose over whether Tupaq - the resident TBI dog - deserved a few scraps from the table.

We wrapped up the field season at the National Museums of Kenya by collecting more data in the vaults. Working in the vaults is always a privilege. Being surrounded by some of the most important fossils in the human evolutionary record is both humbling and inspiring. Nairobi was a comfortable 26 °C (at least ten degrees cooler than Lodwar), still warm enough for a swim after work. It was a refreshing end to a productive season.

We are deeply grateful to the Ng’ipalajem Project and the local community for this remarkable experience. This season’s work - from closing long-standing excavations to uncovering exciting new finds - has brought us one step closer to understanding the palaeoenvironment and landscape use of our Middle Pleistocene ancestors in East Africa and solving the muddle in the middle. We left with renewed curiosity and great anticipation for returning for yet another season of discovery!

Until then, Asante sana Ejok’noi!