Middle Miocene dispersals of apes

The earliest record of fossil apes outside Africa is in the latest early Miocene of Turkey and eastern Europe. There were at least 2, and perhaps 4, species of ape, which were found associated with subtropical mixed environments of forest and more open woodland. Postcranial morphology is similar to that of early Miocene primates and indicates mainly generalized arboreal quadrupedal behaviours similar to those of less specialized New World monkeys such as Cebus. Robust jaws and thick enamelled teeth indicate a hard fruit diet. The 2 best known species of fossil ape are known from the site of Pa?alar in Turkey. They have almost identical molar and jaw morphology. Molar morphology is also similar to that of specimens from Germany and Slovakia, but there are significant differences in the anterior teeth of the 2 Pa?alar species. The more common species, Griphopithecus alpani, shares mainly primitive characters with early and middle Miocene apes in Africa, and it is most similar phenetically to Equatorius africanus from Maboko Island and Kipsaramon. The second species is assigned to a new species of Kenyapithecus, an African genus from Fort Ternan in Kenya, on the basis of a number of shared derived characters of the anterior dentition, and it is considered likely that there is a phylogenetic link between them. The African sites all date from the middle Miocene, similar in age to the Turkish and European ones, and the earliest emigration of apes from Africa coincides with the closure of the Tethys Sea preceding the Langhian transgression. Environments indicated for the African sites are mixtures of seasonal woodlands with some forest vegetation. The postcrania of both African taxa again indicate generalized arboreal adaptation but lacking specialized arboreal function. This middle Miocene radiation of both African and non-African apes was preceded by a radiation of arboreal catarrhine primates in the early Miocene, among which were the earliest apes. The earliest Miocene apes in the genus Proconsul and Rangwapithecus were arboreal, and because of their association with the fruits of evergreen rain forest plants at Mfwangano Island, it would appear that they were forest adapted, i.e. were living in multi-storied evergreen forest. The same or similar species of the same genera from Rusinga Island, together with other genera such as Nyanzapithecus and the small ape Limnopithecus, were associated with plants and animals indicating seasonal woodland environments, probably with gallery forest forming corridors alongside rivers. While the stem ancestors of the Hominoidea were almost certainly forest adapted, the evidence of environments associated with apes in the later part of the early Miocene and the middle Miocene of East Africa indicates more seasonal woodlands, similar to those reconstructed for the middle Miocene of Pa?alar in Turkey. This environmental shift was probably a requisite for the successful emigration of apes out of Africa and made possible later movement between the continents for much of the middle Miocene, including possible re-entry of at least one ape lineage back into Africa.     

Paleosols and paleoenvironments of the middle Miocene,Maboko Formation,Kenya

The middle Miocene (15 Ma) Maboko Formation of Maboko Island and Majiwa Bluffs, southwestern Kenya, has yielded abundant fossils of the earliest known cercopithecoid monkey (Victoriapithecus macinnesi), and of a kenyapithecine hominoid (Kenyapithecus africanus), as well as rare proconsuline (Simiolus leakeyorum, cf. Limnopithecus evansi) and oreopithecine apes (Mabokopithecus clarki, M. pickfordi), and galagids (Komba winamensis). Specific habitat preferences can be interpreted from large collections of primate fossils in different kinds of paleosols (pedotypes). Fossiliferous drab-colored paleosols with iron-manganese nodules (Yom pedotype) are like modern soils of seasonally waterlogged depressions (dambo). Their crumb structure and abundant fine root-traces, as well as scattered large calcareous rhizoconcretions indicate former vegetation of seasonally wet, wooded grassland. Other fossiliferous paleosols are evidence of nyika bushland (Ratong), and early-successional riparian woodland (Dhero). No fossils were found in Mogo paleosols interpreted as saline scrub soils. Very shallow calcic horizons (in Yom, Ratong, and Mogo paleosols) and Na-montmorillonite (in Mogo) are evidence of dry paleoclimate (300-500 mm MAP=mean annual precipitation). This is the driest paleoclimate and most open vegetation yet inferred as a habitat for any Kenyan Miocene apes or monkeys. Victoriapithecus was abundant in dambo wooded grassland (Yom) and riparian woodland (Dhero), a distribution like that of modern vervet monkeys. Kenyapithecus ranged through all these paleosols, but was the most common primate in nyika bushland paleosols (Ratong), comparable to baboons and macaques today. Mabokopithecus was virtually restricted to riparian woodland paleosols (Dhero), and Simiolus had a similar, but marginally wider, distribution. Habitat preferences of Mabokopithecus and Simiolus were like those of modern colobus monkeys and mangabeys. A single specimen of Komba was found in dambo wooded grassland paleosol (Yom), a habitat more like that of the living Senegal bushbaby than of rainforest galagids. A shift to non-forest habitats may explain the terrestrial adaptations of Victoriapithecus, basal to the cercopithecid radiation, and of Kenyapithecus, basal to the hominoid radiation. Both taxa are distinct from earlier Miocene arboreal proconsulines, oreopithecines and galagids.     

Geology and fauna of the middle Miocene hominoid site at Muruyur,Baringo district,Kenya

The middle Miocene sediments assigned to the Muruyur Beds have yielded abundant faunal remains which indicate an age somewhere near the early part of the middle Miocene, perhaps being earlier in time than Fort Ternan but probably coeval or slightly later than Maboko. Available radioisotopic age determinations suggest that the beds are between 13.5 and 14 m.y. old, which seems to be too young when compared with the biostratigraphic estimate. The importance of Muruyur Beds lies in their rich fossil content which includes hominoids of an age which is in general poorly represented in East Africa’s fossil record. This article places the fossil discoveries on record, and discusses their geological context.     

A new hominoid species from the middle Miocene site of Paşalar, Turkey

A new species of fossil hominoid is described from the middle Miocene deposits at Pa?alar, Turkey. It is the less common of the two Pa?alar species discussed by Martin and Andrews (1993), making up approximately 10% of the individuals in the Pa?alar hominoid sample according to analyses of the minimum number of individuals. To the diagnostic features of I(1) described by Alpagut et al. (1990) and Martin and Andrews (1993) can now be added further diagnostic features of all the anterior teeth, as well as both upper premolars and P(3). These include discrete, nonmetric features and metric differences at all the noted tooth positions. Attempts to distinguish the upper and lower molars of the two species have so far been unsuccessful, with the possible exception of M(3). The morphology of the new species is similar in most respects to that of Kenyapithecus wickeri from Fort Ternan, especially concerning maxillary morphology. They share robust and moderately deep maxillary alveolar processes, a restricted maxillary sinus with an elevated and uncomplicated floor, lacking the compartmentalization evident to varying degrees in many other taxa, and a zygomatic process that originates and turns laterally fairly high above the alveolar margin. There are also a number of distinctive similarities in the dentition, particularly for I(1), C(1), P(4) and P(3). The I(1) morphology in particular, with greatly hypertrophied lingual marginal ridges bounding a uniformly thickened basal crown area, is distinctive among Miocene hominoids. All of these similarities serve to reinforce the differences noted by others between the derived morphology of K. wickeri and the more primitive morphology of Equatorius africanus from Maboko and Kipsaramon. The new species differs from K. wickeri in morphological details of most of the anterior and premolar teeth that are known for both species, despite the general morphological similarity, and in the size of I(1) versus I(2). One striking feature of the new species is a relatively large incisive fossa, although it cannot be determined if this is associated with an open palatine fenestra, as in many early Miocene hominoids, or a minimally overlapping palate and nasoalveolar clivus, as in some middle and late Miocene hominoids.     

A New Rhinoceros, Victoriaceros kenyensis gen. et sp. nov., and Other Perissodactyla from the Middle Miocene of Maboko, Kenya

The middle Miocene site of Maboko (Lake Victoria, Kenya), dated to ca. 15 Ma, has yielded one of the best collection of rhinos in Africa. The most common taxon, Victoriaceros kenyensis n.gen., n.sp., is represented by an almost perfect skull (whose main features are the large nasal horn, an orbit located very anteriorly and with a prominent border, and very broad zygomatic arches) and numerous limb bones, probably belonging to only a few individuals. Characters of the teeth and skull support an assignment to the subfamily Elasmotheriinae, a group best known in the middle and upper Miocene, but whose monophyly is disputable, as some of their tooth characters could be adaptations to a grazing diet (in agreement with their distribution in the Maboko beds). In any case, Victoriaceros clearly differs from other East African middle Miocene rhinos, whose diversity is far greater than currently assumed. A few other specimens attest to the occurrence at Maboko of at least one other species, perhaps close to the brachypotheres; a single calcaneum is tentatively assigned to the Chalicotheriidae.     

Hominoid phalanges from the middle Miocene site of Paşalar, Turkey

Eleven proximal and ten intermediate partial or complete hominoid phalanges have been recovered from the middle Miocene site of Pa?alar in Turkey. Based on species representation at Pa?alar, it is likely that most or all of the phalanges belong to Griphopithecus alpani rather than Kenyapithecus kizili, but both species may be represented. All of the complete or nearly complete phalanges appear to be manual, so comparisons to extant and other fossil primate species were limited to manual phalanges. Comparisons were made to extant hominoid and cercopithecoid primate genera expressing a variety of positional repertoires and varying degrees of arboreality and terrestriality. The comparisons consisted of a series of bivariate indices derived from previous publications on Miocene catarrhine phalangeal morphology. The proximal phalanges have dorsally expanded proximal articular surfaces, which is characteristic of cercopithecoids and most other Miocene hominoids, and indicates that the predominant positional behaviors involved pronograde quadrupedalism. Among the extant primates, many of the proximal and intermediate phalangeal indices clearly distinguish more habitually terrestrial taxa from those that are predominantly arboreal, and especially from taxa that commonly engage in suspensory activities. For nearly every index, the values of the Pa?alar phalanges occupy an intermediate position-most similar to values for Pan and, to a lesser extent, Macaca-indicating a generalized morphology and probably the use of both arboreal and terrestrial substrates. At least some terrestrial activity is also compatible with reconstructions of the Pa?alar habitat. Most proximal and intermediate phalanges of other middle and late Miocene hominoids have similar index values to those of the Pa?alar specimens, revealing broadly similar manual phalangeal morphology among many Miocene hominoids.     

On the Middle Miocene avifauna of Maboko Island,Kenya

The Middle Miocene sediments of Maboko Island (Lake Victoria) in western Kenya yielded numerous avian bones, which remained, however, little studied. The significance of this material is shown by the recent identification of an opisthocomiform bird. In the present study, further avian remains from Maboko Island are described. Most of the specimens belong to aquatic or semi-aquatic groups, of which some are closely related to taxa known from Early and Middle Miocene European avifaunas, that is, Nectornis cormorants (N. africanus nov. sp.) and Laricola-like Laromorphae. The fossil material also includes Ciconiidae (cf. Ciconia), Pelecanidae, Phoenicopteridae (Leakeyornis aethiopicus), Musophagidae, and a species of Ardeidae, which closely resembles the taxon Pikaihao from the Early Miocene of New Zealand. Some avian remains from Maboko Island belong to higher-level taxa unknown from the Middle Miocene of Europe. The occurrence of a giant Jacanidae (?Nupharanassa mabokoensis nov. sp.) is of particular interest, because these are globally absent in extant avifaunas and were previously only known from the Late Eocene/Early Oligocene of Egypt. Further unknown from contemporaneous European sites are small representatives of Jacanidae, Bucerotidae, and Alcedinidae, with the fossils of the latter two taxa being among the earliest published records of their respective groups. Several of the taxa that are common in contemporaneous European avifaunas have not been found in Maboko, and in spite of less pronounced climatic differences, Middle Miocene Afrotropical avifaunas already appear to have been distinct from contemporaneous European ones.     

An oreopithecid proximal humerus from the middle miocene of Maboko Island,Kenya

A proximal humerus, recently recovered from the middle Miocene of Maboko Island, Kenya, provides the earliest evidence of postcranial structure and adaptation of Oreopithecidae. Provisionally attributed toNyanzapithecus pickfordi (Harrison, 1986), the specimen manifests a globose head, subequally large tuberosities, and a board, shallow bicipital groove. Although readily distinguished from the fundamentally cercopithecoid proximal humeral morphology ofVictoriapithecus (Senut, 1986), the Maboko Island oreopithecid, shows none of the derived features that are characteristic of the proximal humeri of extant hominoids. It is inferred from proximal humeral anatomy that the Maboko Island oreopithecid was an active arboreal scansor with moderate mobility at the shoulder but lacking adaptations for circumduction of the arm. In combination with craniodental evidence, proximal humeral morphology indicates that Oreopithecidae was a clade of hominoids which originated before the last common ancestor of extant apes and went extinct, without issue, in the later Miocene.     

Afrochoerodon nov. gen. kisumuensis (MacInnes) (Proboscidea,Mammalia) from Cheparawa,Middle Miocene,Kenya

A proboscidean skull from Cheparawa, (Muruyur Formation, Kenya), differs markedly from those of Eurasian Choerolophodon (C. pentelici, C. dhokpathanensis). It is morphologically and metrically close to the holotype of Choerolophodon kisumuensis (MacInnes) a partial skull from Maboko, much of which has been reconstructed in plaster of Paris. The more complete remains of this species now available indicate that it should be placed in a genus separate from Choerolophodon. The new genus Afrochoerodon is erected for it. Choerolophodon ngorora from Ngorora and Fort Ternan (Kenya), Choerolophodon zaltaniensis from Gebel Zelten (Libya) and Choerolophodon chioticus from Chios, Greece, should be transferred to the genus Afrochoerodon. Late Miocene specimens from Nakali, Kenya are probably referrable to the genus Choerolophodon. Fossils from Burji-Soyama (Ethiopia) hitherto assigned to Choerolophodon sp. are excluded from the subfamily Choerolophodontinae.     

New fossil anthropoids from the middle Miocene of East Africa and their bearing on the origin of the oreopithecidae

Recent paleontological collections at the middle Miocene locality of Maboko Island in Kenya, dated at 15-16 million years, have yielded numerous new specimens belonging to at least five species of fossil anthropoids. The most common species of ape at the site, a medium-sized primate with a very distinctive dental morphology, clearly represents a previously undescribed taxon. When compared with other Miocene anthropoids from East Africa, it has its closest affinities with the poorly known species Rangwapithecus vancouveringi from the early Miocene locality of Rusinga Island. The species from Maboko Island is described here as belonging to a new genus of fossil anthropoid, to which "Rangwapithecus" vancouveringi is also referred. The new genus has a highly distinctive suite of derived characters of its molars and premolars, which it shares with Oreopithecus bambolii from the late Miocene of Europe. These synapomorphies indicate a close phyletic relationship between the East African species and Oreopithecus and form the basis for the inclusion of these taxa in a single family, the Oreopithecidae Schwalbe, 1915. In many respects, however, the East African forms are more conservative than Oreopithecus, and in a general sense they can be regarded as an intermediate grade between Oreopithecus and the more generalized early Miocene catarrhines, the proconsuloids. There is, therefore, good fossil evidence to indicate that the origins of the Oreopithecidae can be traced back to the early Miocene of Africa.     

5. JIMMY THE CROW

Harrison, C. J. O. 1980. Fossil birds from Afrotropical Africa in the collection of the British Museum (Natural History). Ostrich 51:92-98.

Although it has a rich avifauna, few fossil birds are know from Africa south of the Sahara. In the present paper 22 species are identified from three Miocene and two Pleistocene localities, 20 being additions to the existing list. A new touraco Apopempsis africanus sp. nov. is described from the Lower Miocene of Songhor, Kenya; and from the same period on Rusinga Island, Kenya, a new stork Ciconia minor sp. nov., in addition to a small flamingo, a hawk and a francol-in. There is evidence of a bustard and a Ciconia stork from the Middle Miocene of Maboko Island, Kenya. In the Pleistocene nine species are listed for Olduvai, Tanzania, and seven for Broken Hill, Zambia. There is some evidence of a shared Afro-tropicai/Palaearctic fuana in the Miocene, and of a larger inland lake bird fauna in the Early Pleistocene of Olduvai, but the Broken Hill material is purely Afrotropical.     

New species of bushbaby from the middle Miocene of Maboko Island, Kenya.

A mandible recovered from ca. 15 million year old deposits of Maboko Island, Kenya, represents the first bushbaby known from the middle Miocene. The specimen is from a new species of Komba, a genus previously known from early Miocene occurrences in western Kenya and northeastern Uganda. Komba is revised, with emended diagnoses proposed for the genus, type-species, and referred species. Komba sp. nov. is distinguished by its larger size and differences of molar cusp acuity, buccal cingulum expression, and mental foramen configuration. Contrary to previous opinion, species of Komba probably diverged prior to the last common ancestor of extant Galaginae, and it is unlikely that they represent early stages of living bushbaby species lineages. Although contemporary Progalago is widely regarded as a galagine, aspects of upper molar, lower premolar, and mandibular corpus morphology indicate that it is more closely related to lorisines. Unlike the greater success currently enjoyed by bushbabies, lorisines were more diverse and almost as abundant as galagines in the early Miocene of eastern Africa.     

Comparative assessment of the ischial morphology of Victoriapithecus macinnesi

An almost complete primate ischium was recovered from middle Miocene (ca. 15 ma) deposits of Maboko Island (Kenya) in 1987. The specimen shows numerous similarities to the ischial morphology of extant cercopithecids and is attributed to Victoriapithecus macinnesi (Von Koenigswald, 1969), the early Old World monkey best known from Maboko Island. The Victoriapithecus ischium provides the first evidence of early Old World monkey pelvic girdle anatomy. The ischium is characterized by an obliquely oriented and broadly flaring tuberosity, a relatively small acetabulum with little ventrally directed curvature of its caudal portion, a long ischial body and a flange-like ischial spine positioned caudal to the rim of the acetabulum. In these features, Victoriapithecus most closely resembles the vervet monkey, Cercopithecus aethiops. The fossil specimen indicates that Victoriapithecus possessed ischial callosities, a mobile tail and adaptations for (possibly cursorial) quadrupedalism with an adducted posture of the thigh. The occurrence of ischial callosities in Victoriapithecus extends the documented antiquity of this feature in catarrhines by more than 12 million years and shows that the distinctive “sitting-sleeping” adaptations of Old World monkeys (Washburn, 1957) originated prior to the divergence of Colobinae and Cercopithecinae. Differences of developmental sequence and tissue composition indicate that the ischial pads of cercopithecids, hylobatids, and pongids may have arisen independently, through parallel evolution. Contrary to Strasser and Delson (1987), discontinuity of ischial callosities was probably the primitive condition for male cercopithecids.     

A new pliopithecoid genus from the early Miocene of Uganda

A partial face and mandible from the early Miocene site of Napak IX in Uganda are described here as a new genus and species of catarrhine primate, Lomorupithecus harrisoni gen. et sp. nov. The face is among the most complete specimens known for a Miocene small-bodied catarrhine. Several aspects of its anatomy indicate that the new species is a stem catarrhine, and as such, it may provide valuable information pertaining to the primitive catarrhine cranial morphotype. Lomorupithecus is most similar in its facial anatomy to members of the Pliopithecoidea, and these similarities could be interpreted in three ways. They could be symplesiomorphies, which would support the traditional view of the primitive catarrhine cranial morphotype; they could be synapomorphies reflecting a phylogenetic position of Lomorupithecus within Pliopithecoidea; or they could represent convergence. Phylogenetic analysis of Lomorupithecus along with 35 other primates indicates that it is a pliopithecoid. As such, it would be the oldest and only Afro-Arabian member of this otherwise Eurasian clade.     

The paleoenvironment of Sivapithecus parvada

Remains of the hominoid Sivapithecus parvada and a diversity of mammalian taxa are preserved at locality Y311 (ca. 10 Ma) in the Siwalik Nagri Formation of northern Pakistan. Bovids (Bovidae, Artiodactyla) are the most abundant mammals next to tragulids (Tragulidae, Artiodactyla) at locality Y311 and provide a means for reconstructing the paleoenvironments that would have been available to Sivapithecus parvada. A functional model indicates a linkage between habitat and several femoral characters among extant bovids. Based on this model, we infer that forested habitats predominated at locality Y311 but that some less densely covered areas may also have been present. Paleoenvironments in the earlier Chinji Formation appear comparable to those at locality Y311, although the presence of a continuous canopy in the former is more certain. Thus, adaptive changes in the bovid fauna from the Chinji through the Nagri Formations appear to have preceded the shift to predominantly C4 grasslands which, based on other lines of evidence, occurred locally (and possibly globally) between 8 and 6 Ma. The paleoenvironments of locality Y311 and the Chinji Formation localities appear different from the paleoenvironment of Kenyapithecus at Fort Ternan in Kenya, where the presence of continuous canopy is unlikely. The Fort Ternan fauna is dominated by two genera of bovids. One of these is adapted to light cover while the other appears better adapted to heavy cover. Sivapithecus and Kenyapithecus lived in different ecological settings probably characterized by varying degrees of vegetative cover.     

Fossil wood flora of the early Miocene Nawamata formation of Monzen,Noto Peninsula,central Japan

Silicified wood collected from the Lower Miocene Nawamata Formation at two localities, Nakaya and Nigoriike, Monzen-machi, Noto Peninsula, central Japan, were identified. Among the 58 specimens there are two species of conifers and eleven species of dicotyledons:Taxodioxylon cunninghamioides (Watari) Watari andT. sequoianum (Merckl.) Gothan (both Taxodiaceae),Carya protojaponica Watari (Juglandaceae),Pterocarya rhoifolia Siebold et Zucc. (Juglandaceae),Ostrya monzenensis sp. nov. (Betulaceae),Quercus anataiensis (Watari) Watari (Fagaceae),Liquidambar hisauchii comb. nov. (Hamamelidaceae),Prunus iwatense (Watari) Takahashi et Suzuki (Rosaceae),Gleditsia paleojaponica comb. nov. (Leguminosae),Acer watarianum Takahashi et Suzuki (Aceraceae),Meliosma mio-oldhami sp. nov. (Sabiaceae),Reevesia miocenica Watari (Sterculiaceae), andFraxinus notoensis sp. nov. (Oleaceae). The fossil wood floras at the two localities are compared to the Daijima Flora, and warm-and/or cool-temperate mesic forests are suggested to occur in the Early Miocene of Monzen.     

Victoriapithecus: The key to Old World monkey and catarrhine origins

The past ten years have witnessed major changes in reconstructions of the history of Old World monkeys, most of them driven by new material of the Miocene monkey Victoriapithecus from Maboko Island, Kenya. Before the mid-1980s, predictions about the morphological and ecological adaptations of the earliest cercopithecoids relied heavily on evidence from extant colobine and cercopithecine monkeys. It was argued that the earliest cercopithecoids were largely or at least partly folivorous, had short colobine-like faces, and were arboreal. The only studies suggesting that some of these arguments were not true were based on limited knowledge of the anatomy of Victoriapithecus. The presence of semi-terrestrial adaptations in middle Miocene monkeys hinted to some that early monkeys may not have been arboreal. Others attempted to cope with the discrepancy between neontological predictions and the fossil evidence by proposing that limb bones with stronger terrestrial adaptations within the Maboko sample were derived cercopithecine remains, while those with more arboreal features belonged in the subfamily Colobinae and should be regarded as primitive.     

Tooth microwear and premaxillary shape of an archaic antelope

Extant ungulates can be divided into three dietary categories: browsing feeders, grazing feeders, and mixed feeders. Dietary adaptations can be differentiated in extinct ruminants based upon tooth microwear analysis as well as evaluation of premaxillary morphology. Tooth microwear shows that the extinct bovid Kipsigicerus labidotus from the Miocene of Fort Ternan in Kenya (14 million years old) was most likely a grazing feeder, with mixed-feeder tendencies, while morphologically the premaxilla most closely resembles that of a mixed feeder. Because the paleoenvironment at Fort Ternan was likely to have been forested, as shown by paleosol isotopic studies, grazing in this particular ruminant evolved within a forested environment preceding the origin of savanna. □ Tooth microwear, premaxilla, Miocene, Kenya, bovid, paleodiet.     

A new cave-dwelling and endemic species of the genus Pholeuonopsis (Coleoptera, Leiodidae) from Serbia

In the present study, a new species of a cavernicolous beetle is described from Serbia: Pholeuonopsis (Pholeuonopsis) zlatiborensis sp. n. (Leptodirini, Cholevinae, Leiodidae). All important taxonomic features have been thoroughly analyzed and illustrated. The new species probably belongs to an old phyletic lineage of mesogeid origin, like other known Pholeuonopsis species inhabiting cave and endogean habitats in the western part of the Balkan Peninsula. Therefore, the species is both relict and endemic inhabitant of cave habitats in Serbia.     

Problems in the interpretation of Ramapithecus: with special reference to anterior tooth reduction

The dental proportions of Ramapithecus specimen FT 1271-2 (from Fort Ternan, Kenya) have been compared with undoubted fossil pongids from the Miocene of East Africa. Compared to its Miocene pongid contemporaries, Ramapithecus exhibits distinct anterior tooth reduction both in its incisor and canine dimensions. This distinction is most clearly seen in comparisons of Ramapithecus with pongids of similar cheek tooth size, i.e., Dryopithecus africanus and Pan paniscus. The differences in dental proportions between the phylogenetic lines of D. africanus to Pan and Ramapithecus to Homo are discussed in terms of various dietary hypotheses. The similarities in dental proportions of Gorilla and Ramapithecus illustrate their non-frugivorous dietary preferences, but have little or no value as far as the taxonomic assessment of Ramapithecus is concerned.