Brain Morphology Of Homo Liujiang Cranium Fossil Detailed With 3-D CT Scan

High-resolution industrial computed tomography was used to scan the Homo Liujiang cranium fossil, and the three-dimensional virtual brain image was reconstructed. More information for the phyletic evaluation of the Homo Liujiang was derived from this new research.

Hominin fossils are the most important materials to explore human origins and evolution. Since most hominin fossils are incomplete, or filled with a heavy calcified matrix, it is difficult or often impossible to reconstruct the endocast in a real fossil without destroying it. Accordingly, traditional methods limited the study of human brain evolution.

CT can explore fossils in a noninvasive way by transforming a real fossil into a virtual object, and make it possible for paleoanthropologists to extend the study of fossil specimens from the exterior to the interior. Using high-resolution industrial CT, the Homo Liujiang brain image was reconstructed.

The Liujiang cranium is the most complete and well-preserved late Pleistocene human fossils ever unearthed in South China. Because the endocranial cavity is filled with hard stone matrix, earlier studies focused only on the exterior morphology of the specimen using the traditional methods. Arguments about the phyletic evaluation of the Liujiang hominin fossil have existed for a long time.

The new research was led by Wu Xiujie from Institute of Vertebrate Paleontology and Paleoanthropology (IVPP).

In this study, the authors used high-resolution industrial CT to scan the Liujiang cranium, and reconstruct the three-dimensional (3-D) brain image. Compared with the endocasts of the hominin fossils and modern Chinese, most morphological features of the Liujiang brain are in common with modern humans, including a round brain shape, bulged and wide frontal lobes, an enlarged brain height, a full orbital margin and long parietal lobes.

There are a few differences between Liujiang and the modern Chinese in our sample, including a strong posterior projection of the occipital lobes, and a reduced cerebellar lobe. The measurement of the virtual endocast shows that the endocranial capacity of Liujiang is 1567 cc, which is in the range of Late Homo sapiens and much beyond the mean of modern humans. The brain morphology of Liujiang is assigned to Late Homo sapiens.

IVPP is the only special institute mainly dealing with the research of origin and evolutionary history of hominin fossils. In the past 80 years, a few complete hominin crania fossila were found in China. "With CT scanning and 3D visualization techniques to reconstruct virtual specimens, it is now possible for Chinese hominin paleontologists to conduct paleoneurological studies of our national treasures", said Dr. Wu Xiujie.

The study is supported by the National Natural Science Foundation of China.

SOURCE : Science in China Press