Image credit Yohannes Haile-Selassie
The Burtele Foot is a partial hominin foot found at the site Woranso-Mille, in the Afar region of Ethiopia, and described in 2012. The foot was found at Burtele locality 2, where the sediments have been dated to around 3.4 million years ago, making the individual a contemporary of multiple hominin species. It has not been assigned to any particular species, as it does not match the morphology of any known hominin species from the time. What makes the foot so intriguing is that the morphology of the Burtele foot is different from the foot of Australopithecus afarensis, a species that was also living in the same place and time. The difference in morphology suggests that there were at least two different modes of locomotion present in hominin species at the time.
Au. afarensis, as we know from its foot bones, other postcranial (the rest of the skeleton apart from the skull) remains, and the footprints its members left behind at Laetoli (Tanzania) 3.6 million years ago, was bipedal. Compared to the foot of Au. afarensis, the Burtele foot instead has an opposable big toe—meaning that the big toe was able to move independently of the rest of the toes, similar to the toes of living apes what are similar to our own opposable thumbs. In Au. afarensis, the big toe is pulled in line with the rest of the toes, in contrast.
Due to the divergent morphology of the Burtele foot compared to other hominin species known from the time, researchers consider the specimen as the best evidence of multiple hominin species living contemporaneously.
