关键词: 森林古猿类;江淮宽齿猿;中新世;江苏

Abstract: This paper deals with a new form o￡ Dryopithecini represented by 3 isolated upper mo_x001f_lars and 2 lower molars found in Songlin Village, Sihong County, Jiangsu Province. Based on the morphological characters of these materials, new generic and specific names (Platodonto- pith ecus jianghuaiensis) have been proposed by the authors. Because of the fact that this site has yielded many other fossil mammals (including Dionysopithecus shuangouensis; Li 1978), its geological age may be middle/later miocene according to previous analyses.
The criteria used in defining the new genus are tentatively given as follows:there are four cusps on first two molars; the protocone is the largest, while the other three cusps are equal in size on M2; the metacone of M1 is smaller than the paracone and hypocone; a buccal groove on M1 is clearly present; distal and lingual grooves can be slightly seen; on the first two molars the lingual cingulum is strong and extends backward to the posterior margin of the crown. There is a buccal cingulum between the paracone and the metacone on M1; the buccal cingulum of M2 is quite well developed, and a Carabelli cusp projects on the buccal cingulum; the protocone of M3 is the largest, but the metacone is greatly reduced in size; the metacone may be lacking so that the distal end of the teeth are abbreviated; there is a slight cuspule on the distal cingulum which may represent the metacone; both crista obliqua are present, one runs from the protocone, with many breaks, to the buccal border of the teeth; the other runs from the protocone to the mesial cingulum; the mesial lingual and distal development of the cingulum are the same as on M1 and M2. The upper molars, the first two molars particularly, are relatively broad in relation to their length； the width of M2 is larger than that of M3; M3 is longer than M2, but their average values are similar to each other, thus we have the following sequence of sizes of upper molars: M3 M2 > M1. The lower molars include an M3 and a fragmentary M2 or M3. They are five-cusped and have a low crown and a distinct cingulum on the buccal border.
Platodontopithecus Jianghuaiensis differs from fossil anthropoids found in Kaiyuan County and Lufeng County, Yunnan Province, n size and thickness of enamel on the crown. The cingula of the Sihong specimens are extremely well developed in the upper molars and in the buccal aspect of the lower molar, but upper and lower molars found in Yunnan Province lack this feature.
The teeth found in Sihong County also differ from those of Dionysopithecus shuangou- ensis found at the same site. The upper molars of D. shuangouensis are smaller and rounder than those found in Sihong County. The sequence of upper molars of the former is M2 A M1 2 M3; while the latter is M2 > Ml.
The upper molars of P. jianghuaiensis have some features in common with the African Dryopithecinae. For example, Proconsul and Limnopithecus both possess lingual cigulum on the upper molars and buccal cingulum on the lower molars, but they are different in size and in the sequence of the upper molars. P. jianghuaiensis is M2 > M1, while Procon_x001F_sul and Limnopithecus .are M2 > M3 > Ml. In size P. jianghuaiensis. falls between Proconsul africanus and Dendropithecus macinnesi (see bivariate plot, Fig. 5—8). P. jianghuaiensis may be distinguished from D. macinnesi by the following features: M3M2M1 hypocone, paracone and metacone of equal size on upper molars; on lower molars the cusps lie close to one another and lack a well developed ridge system.
It is important to note that P. jianghuaiensis is the first Miocene ape recorded in eastern China, therefore the erection of a new genus and species may be appropriate.
That Dryopithecus is an ancestor of both recent apes and of Sivapithecus appears to be the consensus of opinion today. Undoubtedly, P. jianghuaiensis, from the Miocene deposits of Asia, provides the evidence that DryopUhecus-like forms had already come into existence in that epoch, although the relationships between the Miocene apes of Asia and Africa await explanation. One factor that must be taken into consideration is that a new form of Dryopi-thecus in eastern China had emerged by the middle Miocene.

Key words: Dryopithecinae; Platodonto pith ecus jianghuaiensis; Miocene; Jiangsu