A New Virtual Reconstruction of the Ndutu Cranium

Identifier:  imarina:9295559

Handle: https://hdl.handle.net/20.500.11797/imarina9295559

Authors:  Montiel, Gustavo; Lorenzo, Carlos

Abstract:
The Ndutu cranium is a partial, fragmented, and distorted hominin specimen from the Lake Ndutu site in Tanzania. It was first reconstructed by R. J. Clarke in 1976 and later revisited using now-outdated techniques. Consequently, features such as facial projection, cranial height/length, and cranial flexion are contestable. Here, we present a new virtual reconstruction following a transparent and replicable approach that employs virtual anthropology techniques to reassemble, mirror, digitally align, complete the cranium, and remove the effect of plastic deformation. Before deciding on an approach to align the unarticulated fragments, we tested the effects of symmetrization and the use of surface semilandmarks on the performance of our tool of choice: the digital alignment tool (DTA), developed by A. Profico and colleagues in 2019. Upon completion, we compare our reconstruction to a sample of Pleistocene hominin crania via geometric morphometrics. Test results reveal that DTA performance varies by fragment and that the use of surface semilandmarks bears no statistically significant advantage. We found our reconstruction to boast a more prognate and narrower face with a less flexed cranium overall than previous reconstruction efforts. The shape of the reconstructed cranial vault of Ndutu resulted closest to Sima de los Huesos (SH) 5, while its sagittal profile was most similar to Kabwe's, lending support to J. L. Arsuaga and colleagues' 1997 work and to P. Rightmire's, respectively. We warn that further work is necessary before settling the debate surrounding Ndutu's phylogeny. However, if our reconstruction hypothesis is held, its inclusion in future morphological studies is granted.