Dr. T. Tóth szerk.: Studia historico-anthropologica (Anthropologia Hungarica 20. Budapest, 1988)

With the aid of the vertical section of the maxilla it can also be demonstrated that in Rudapithecus the sagittal axes of the M

ù teeth converge toward the mandible while in all other extinct or recent apes investigated so far they diverge. At the same time they are more or less parallel in man and in the "Taung baby" (Fig. 6). The very strong lingual attrition on the M

1 and M

2 teeth of the RUD-77 skull is by all means due to this. It is highly probable that the converging type was the more archaic one. The "Asian" type had already abandoned this trait by 6-8 myrs. Probably the same development took place in the chimpanzee+gorilla line from 5-6 myrs onwards. However, strongly diverging axes did not develop during the process of hominization. THE MAXILLARY DENTAL ARCH The maxillary dental arch - in accordance with changes in the cerebral part of the skull - is a characteristically changing morphological trait, though it does not denote specific differences. A very probable reconstruction of the maxillary dental arch of Rudapithecus had already been carried out before by using RUD-12 and RUD-77 finds (KORDOS 1987b). The result is a regular "U-shaped" arch. The M

3-P^ teeth are situated in a straight line and the two dental rows are parallel to each other. The curvature of the dental row begins at the canine. The dental arch of the female Sivapithecus lufengensis (P.A. 677) had not been reconstructed so far, because as a result of compression the bones of the maxilla, together with the teeth, had moved from their original position. After a detailed study of this find one may try to reconstruct the original dental arch. During this reconstruction the starting point was given by the horizontal part of the palatine with the M

2-M

3 teeth on both sides (Fig. 7), because they have remained in their original form. The fragment of the right-side bony palate with the M*-P

3 teeth has slightly shifted over this part. Taking into consideration the contact surfaces of M* and M

2

, this fragment could be joint to the earlier separated fragment of the palatine. The original find has been broken and removed in the line of the right canine and it is distorted at the incisive teeth. Taking into account other Lufeng finds during the reconstruction process, it became clear that the jointing of this part resulted a diasteme between the canine and the lateral incisives. I made several possible reconstructions for the dental arch but they differ from each other only in insignificant details. In all these versions the P

3-M^ teeth are in the same axis and the two dental rows slightly diverge toward the M

3

. They became considerably narrower at the frontal arch. Therefore the maxillary dental arch does not show the regular "U" form but it is a transitional form between "U" and "V" shapes. It is only the frontal part of the maxillary bone of the Lufeng male skull (P.A. 644) (Fig. 7) which has remained without distortion. This part (together with the canines and incisive teeth) shows the same reduced form which appears in the female specimen. The P

3-M

2 toothrows diverge considerably. All these phenomena suggest the existence of a marked sexual dimorphism within the same taxa among Chinese finds. Summarizing the present knowledge of the maxillary dental arch of Rudapithecus hungaricus and Sivapithecus lufengensis, one may state that the Rudapithecus find, which is 3-4 million years older than the Lufeng one, seems to be more "modernized". In addition there are fundamental morphological differences in the frontal arches of the two finds. COMPARISON OF TEETH FROM RUDABÁNYA AND LUFENG While the anatomical analysis of the Lufeng teeth has been already published (WU RUKANG al. 1985, 1986), only part of the Rudabánya teeth have already been described (KRETZOI 1975, KORDOS 1987b). However, even this comparison, based on a relatively few finds, is enough to draw attention to some morphological peculiarities. The central incisor of Sivapithecus indicus is twice as large as the lateral incisor. At the same time this difference is not observable in Rudapithecus hungaricus, where the incisors are practically of the same measurements. The sagittal measurement of the alveole of RUD-12 is 7.7 mm for the central incisor and 7.0 mm for the lateral one. Consequently, the latter tooth is smaller only by 9-10% than the central incisor.