Discerning carnivore agency through the three-dimensional study of tooth pits: Revisiting crocodile feeding behaviour at FLK- Zinj and FLK NN3 (Olduvai Gorge, Tanzania)

Hominins and carnivores have shared similar habitats in Africa, evolving as direct competitors for the same prey and spaces. The overlap of their ecological niches has raised an important debate on the role that carnivores played in archaeological site formation. Different analytical techniques differentiate the action of carnivores and humans and identify the type of carnivore involved of which tooth mark analyses are prominent. However, available taphonomic studies present some limitations given the great overlap among tooth mark sizes from different carnivores, enabling only the distinction of size groups, not specific carnivores. In this work, we use a new technique combining three-dimensional (3D) reconstruction and geometric morphometrics (GMM) of tooth pits on equid and bovid bone created by different carnivores (including crocodiles, hyenas, jaguars, lions and wolves) in controlled settings. The 3D methodology we present isolates and differentiates tooth marks generated by different carnivores. We also test the applicability of the technique to ascribe tooth pits recorded on some hominin specimens from FLK Zinj and FLKNN 3 (Bed I, Olduvai Gorge). The tooth marks on the Olduvai OH8 and OH35 hominin fossils, previously assigned to crocodiles show that while OH8 tooth pit morphology falls in the range created by crocodiles, the pits on OH35 can not be interpreted as crocodile-inflicted marks.