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SKULL IX

It is a name of a fossilized cranium of Homo erectus found in kampung Tanjung, Sangiran on May 1993. Therefore, it is also labeled as Tjg-1993.05. The announcement of this find had been carried out by Sartono and Tyler in the International conference on Human Paleoecology held at Jakarta on October 1993. The comparison of this cranium with other Homo erectus’s cranium from Sangiran, Ngandong, Trinil as well as Zhoukoudian from China had been done and it was published by Arif et.al., in 2001 and 2002. Currently, Skull IX is housed at the Department of Geology, Institute of Technology Bandung (ITB), Indonesia.

Late Professor Sartono said that Skull IX was found by Mr.Sugeng, a local farmer (now he has passed away), at kampung Tanjung when he was walking down a cliff. Although Skull IX was a surface find, Sartono and Tyler (1993) claimed that it possibly came from the level of Upper Tuff of the Bapang (Kabuh) formation.

The Skull IX is the second best Homo erectus cranium ever found in Java after S-17. It consists of three separated parts, namely, the vault, most of part of the maxilla and the right temporal bone. The maxilla consists of seven crowns, that are, complete right upper first, second and third molars (UM1-UM3), a lingual half of the right upper forth premolar (UP4), a disto-lingual quarter of the right upper third premolar (UP3), a distal half of the left upper second molar (UM2) and lingual two thirds of the left upper third molar (UM3).

The Skull IX was reconstructed after the discovery, using the glue mixed with epoxy resin and sand. But the reconstructed skull is distorted, especially on the left side of the vault. Furthermore, some of the teeth were glued in wrong position. The left upper third molar (UM3) was moved to the position between the left upper forth premolar (UP4) and the left upper first molar (UM1). In the occlusal aspect, the left upper third molar (UM3) was turned clock wise about 90 degrees and the left upper second molar (UM2) was also turned anti-clock wise about 90 degrees.

On behalf the reconstruction of vault, we firstly made a plaster cast of Skull IX on March 1997 at the Department of Geology, Institute of Technology Bandung (ITB), Indonesia. The the cast of the vault was cut into 16 pieces and they were joined together in appropriate positions in order to adjust distortion of the original.

We encountered some difficulties when interpreted the sex of Skull IX. Relatively small overall vault size (the endocranial volume of the cast was about 840 ml), rounded frontal aquama and slight projection of the occipital torus suggested that the Skull IX was a female individual. But, strong development of the supraorbital torus (SOT) and robust maxilla suggested the Skull IX was a male.

The interpretation of age of Skull IX was based on the sutures on the vault, the dental wear and the UM3’s eruption. The sutures of the vault were mostly closed or obscure but still open in the posterior part of the sagittal suture. The lingual cusps of the right first molar (UM1) was worn and a dentine island was exposed. The third molars (UM3) had already erupted and were worn moderately. These features suggested that Skull IX was a young adult at the age of death.

References
Arif, J., H. Baba, M.E. Suparka, Y. Zaim, T. Setoguchi. 2001. Preliminary study of Homo erectus Skull IX (Tjg-1993.05) from Sangiran, Central Java., Indonesia. Bulletin of Natural Science Museum, Tokyo, Ser.D, 27: 1-17.

Arif, J., Y. Kaifu, H. Baba, M.E. Suparka, Y. Zaim, T. Setoguchi. 2002. Preliminary observation of a new cranium of Homo erectus (Tjg-1993.05) from Sangiran, Central Jawa. Anthropological Science, 110(2): 165-177.

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Posted in Uncategorized 7 years, 11 months ago at 9:46 pm.

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