Malapa Hominin 1—MH1

Consider the implications of this cranium—fragmentation and distortion—that could have slight alterations on the described cranial morphologies. The smallest estimate for cranial capacity of MH1 is 420 cubic centimeters, which is considerably small for genus Homo. The shape of the brain cavity is egg-shaped with the sides and roof of the cranium (parietal walls) in an upright extended form. Behind the eye sockets there is a slight narrowing of the cranium that suggests intermediate chewing muscles. The brow ridge above the eye socket (supraorbital torus) is less pronounced, and there is faint depression between the brow ridge and frontal bone (supratoral sulcus); these morphological traits are more humanlike. The region located between the eyebrow ridge and above the nose (glabellar region) appears to be more primitive than derived. Cheekbones do not protrude or flare (lack of zygomatic flaring) which allows for a square-shaped face when viewed at an angle directed upwards. The pear-shaped nose opening has greater cartilage portions, which makes for a wide flare at the lowest point of the nasal bones, but no nasal bone projection above the shared joints of the frontal bone and jawbone (frontomaxillary suture). Beneath the nose, there is an average sized jaw with slight projection (mesognathic); these primitive character traits are similar in morphology to australopiths. 

Conroy, Glenn C., and Herman Pontzer. Reconstructing Human Origins: A Modern Synthesis. 3rd ed., New York & London, W. W. Norton & Company, Inc., 2012, pp. 190-192.

Berger, L. R., D. J. De Ruiter, S. E. Churchill, P. Schmid, K. J. Carlson, P. H. G. M. Dirks, and J. M. Kibii. "Australopithecus Sediba: A New Species of Homo-Like Australopith from South Africa." Science 328.5975 (2010): 195-204. Web. 18 Apr. 2017. <http://science.sciencemag.org/content/328/5975/195.full>.