Paleoenvironmental reconstruction of middle Miocene paleosols bearing Kenyapithecus and Victoriapithecus, Nyakach Formation, southwestern Kenya

Paleosols in the middle Miocene (15 Ma) Nyakach Formation at Kaimogool, near Sondu, southwestern Kenya have yielded specimens of the early cercopithecoid Victoriapithecus macinnesi and the early kenyapithecine Kenyapithecus africanus, and can be used as evidence for the environmental mosaic occupied by these primates. Five distinct types of paleosols (pedotypes) are recognized in the Nyakach Formation section at Kaimogool South. The most common paleosols are reddish brown, silty calcareous profiles with blocky structure and large root traces (Ratong pedotype) which are interpreted as soils of well-drained, dry bushland or thicket (nyika). Weakly developed paleosols associated with paleochannels (Dhero pedotype) represent wooded grassland early in the ecological succession from streamside flooding. One of these paleosols has yielded a fossil flora of grasses and small-leaved dicots like those of modern semi-arid wooded grassland. Crumb structured, calcareous paleosols with iron-manganese nodules (Yom pedotype) are interpreted to represent seasonally waterlogged, wooded grassland (dambo or vlei). Thick, red clayey, calcareous paleosols with blocky ped structure and large root traces (Tut pedotype) are interpreted as soils of well-drained dry woodland. Other blocky-structured, gray to brown calcareous paleosols with iron-manganese nodules (Chido pedotype) are interpreted as soils of seasonally waterlogged, riparian dry woodland. Fossil soils, plants and gastropods are evidence of an unusually dry (300-500 mm mean annual precipitation) habitat for apes, consisting of a vegetational mosaic dominated by dry woodland, bushland and thickets with few areas of seasonally waterlogged grassland. Fossils of V. macinnesi are rare from Nyakach, but were found in paleosols representative of bushland and thicket habitats (Ratong). Fossils of the ape K. africanus were found within paleosols indicative of dry woodland (Tut). Other paleosol types representative of seasonally dry dambo grassland (Yom), colonizing grassland (Dhero) or riparian woodland (Chido) are also represented, but have not yet produced primate fossils.     

A reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhines from fort Ternan,Kenya

This paper presents a reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhine primates from the important middle Miocene site of Fort Ternan in Kenya. Although the sample of specimens is rather small, the material can be attributed to at least five different species, identified here asKenyapithecus wickeri, Proconsul sp., a large species of oreopithecid,Simiolus sp., and a small species of catarrhine of indeterminate status.Kenyapithecus wickeri probably represents a conservative sister-taxon of the extant large hominoids. It is more derived than“Sivapithecus” africanus from Maboko Island, from which it can be distinguished at the generic level. A small species of catarrhine from Fort Ternan can be attributed toSimiolus. It is probably a different species fromSimiolus enjiessi from the early Miocene of East Africa, but additional material is needed to confirm its taxonomic distinctiveness. The occurrence of at least five species of catarrhine primates at Fort Ternan confirms that species diversity levels were as high during the middle Miocene as they had been during the early Miocene. However, the overall taxonomic and ecological composition of the middle Miocene catarrhine community was quite different, evidently due to a significant change in the local ecological setting. Taxonomic differences between the catarrhine faunas at Fort Ternan and Maboko Island can probably be explained as a consequence of a chronological separation between the two sites, and, to a lesser degree, to paleoecological differences.     

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.     

Stratigraphy, artefact industries and hominid associations for Sterkfontein, member 5

A revised stratigraphy for the early hominid site of Sterkfontein (Gauteng Province, South Africa) reveals a complex distribution of infills in the main excavation area between 2.8 and 1.4 m.y.a, as well as deposits dating to the mid to late Pleistocene. New research now shows that the Member 4 australopithecine breccia (2.8-2.6 Ma) extends further west than was previously thought, while a late phase of Member 4 is recognized in a southern area. The artefact-bearing breccias were defined sedimentologically as Member 5, but one supposed part of these younger breccias, the StW 53 infill, lacks in situ stone tools, although it does appear to post-date 2.6 Ma when artefacts first appear in the archaeological record. The StW 53 hominid, previously referred to Homo habilis, is here argued to be Australopithecus. The first artefact-bearing breccia of Member 5 is the Oldowan Infill, estimated at 2-1.7 Ma. It occupies a restricted distribution in Member 5 east and contains an expedient, flake-based tool industry associated with a few fossils of Paranthropos robustus. An enlarged cave opening subsequently admitted one or more Early Acheulean infills associated in Member 5 west with Homo ergaster. The artefacts attest to a larger site accumulation between ca. 1.7 and 1.4 Ma, with more intensive use of quartzite over quartz and a subtle but important shift to large flakes and heavier-duty tools. The available information on palaeoenvironments is summarized, showing an overall change from tropical to sub-tropical gallery forest, forest fringe and woodland conditions in Member 4 to more open woodland and grassland habitats in the later units, but with suggestions of a wet localized topography in the Paranthropus -bearing Oldowan Infill.     

Upperlimb skeletal elements of miocene cercopithecoids from east Africa: Implications for function and taxonomy

Old collections and unpublished newly-discovered specimens of Miocene cercopithecoids studied here include humeri and proximal ulnae from Maboko (KNM MB 2, KNM MB 3, KNM MB 19, KNM MB 32, KNM MB 12038, KNM MB 12044), Nyakach (KNM NC 9824) in Kenya and from Napak (NAP V-8.85) in Uganda. This work leads to the conclusion that two different groups of monkeys may have co-existed in East Africa in the Middle Miocene. After comparison with extant cercopithecoids (Colobus polykomos, Colobus badius, Colubus angolensis, Colobus guereza, Cercopithecus aethiops, Cercopithecus ascanius, Nasalis larvatus, Presbytis entellus and severalPapio andMacaca), the fossils can be divided into two morphological groups. In the distal humerus, the shape of thetrochlea humeri and the orientation of theepicondylus medialis are distinctive; in the ulnae, the distinction is mainly based on the morphology of theincisura trochlearis. Thus, we would have a more terrestrial group and a more arboreal one. The differences (not linked with sex) are large enough to indicate a taxonomic difference (as proposed on the teeth collected to the same sites, by several authors). At this stage, we cannot assign with certainty the specimens to one taxon or the other (Victoriapithecus macinnesi orVictoriapithecus leakeyi).     

Tooth Wear Difference Between the Yuanmou Hominoid and <Emphasis Type="Italic">Lufengpithecus</Emphasis>

The Late Miocene hominoids recovered from Lufeng (Lufengpithecus) and Yuanmou of Yunnan Province, China, are among the most numerous hominoid fossils in Eurasia. They have yielded critical evidence for the evolutionary history, biogeography and paleobiology of Miocene hominoids. We examined and compared the wear pattern and differences of 804 molars of the Yuanmou hominoid and Lufengpithecus. Our results indicate that both the upper and lower molars of the Yuanmou hominoids were more heavily worn than those of Lufengpithecus. The wear patterns of the individual molars between the Yuanmou hominoid and Lufengpithecus also are different. The heaviest wear of lower molars of the Yuanmou hominoid occur in M₂, followed by M₁ and M₃. In Lufengpithecus, M₁ and M₃ were more heavily worn than M₂. There are differences in wear between the upper and lower molars for the two hominoids. Among the various factors related to tooth wear, we suggest that the main reason for the tooth wear differences between the Yuanmou hominoid and Lufengpithecus may be that they had different diets. More soft dietary items like leaves and berries were probably consumed by Lufengpithecus, and the Yuanmou hominoid may mainly have feed on harder or frugivorous diets. This result complements findings from previous studies of tooth size proportion, and the development of lower molar shearing crests in the 2 samples. Enamel thickness, living environment, behavior patterns, and population structure also might account for dental wear differences between the Yuanmou hominoid and Lufengpithecus.     

云南元谋古猿生活时期自然环境的讨论

元谋古猿生活时期的自然环境是森林草原或疏林-草原,还是茂密的森林? 气候是凉干还是温暖潮湿? 本文试图从云南6个最具代表性中新世沉积盆地取得的丰富植物大化石和孢粉资料分析, 论证了中新世时期云南曾广泛分布热带或亚热带常绿阔叶林或落叶阔叶和常绿阔叶混交林。气候温暖湿润。至中新世最晚期, 落叶阔叶林和针叶林分布面积扩大, 气候变得凉干。与元谋古猿相邻的禄丰古猿生活时期及其前后正是经历了相同的环境变迁过程。由此推论元谋古猿生活时期的自然环境为茂密的森林, 气候温暖湿润。最后, 就《元谋古猿》专著对古猿生活时期的自然环境分析存在的问题进行了讨论。     

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.     

Reassessment of the paleoenvironment and preservation of hominid fossils from Hadar, Ethiopia.

Samples of paleosols from locality AL-333, known for numerous specimens of Australopithecus afarensis, were analyzed in order to reconstruct the original soils and environment of burial of the associated fossil hominids. The bones were found in swale-like features, within the calcareous and coarse-grained basal portion of a paleosol. This is more like an assemblage of bones buried during a single depositional episode, such as a flood, than an assemblage accumulated on a soil over a long period of time by carnivores or other means of death. What killed the hominids remains unclear, but considering the association of originally disarticulated bones of such hydraulically distinct types as phalanges and maxillae, it is very likely that they died and partially rotted at or very near this site. The paleosols at AL-333, here named the Fo and Go clay paleosols, have calcareous rhizoconcretions, granular surface horizons, prismatic peds, and shallow calcareous nodules and stringers like soils now supporting grassy woodland in semiarid regions. Although this group of hominids was buried in streamside gallery woodland, there is evidence from Laetoli, Tanzania, that A. afarensis ventured out into open wooded grassland as well. Evidence for this should be sought from other paleosols at Hadar.     

Plio-Pleistocene cercopithecids from Kanam East, western Kenya

This paper describes cercopithecid craniodental and postcranial fossils recovered by L. S. B. Leakey at Kanam East, Kenya during the early 1930s. These fossil monkeys have been generally assumed to have been derived from early Pliocene horizons, but their exact geographical and stratigraphical provenience is unknown. Although the question of the evolutionary significance of these specimens must await the recovery of more securely dated material from Kanam East, some general conclusions can be drawn concerning their taxonomic affinities and paleobiology. Based on comparative studies of the craniodental material, at least three extant genera are represented—Colobus,Lophocebus, andCercopithecus. The postcranial fossils include a number of hindlimb specimens, as well as the manubrium of a sternum and a caudal vertebra. Identification of the postcranial remains to particular genera is not possible, but they are similar in morphology to modern arboreal and semiterrestrial cercopithecid monkeys of small to medium size. It is evident that Kanam East had a diverse cercopithecid community, similar to those found today in forested and woodland habitats, and this may be of some significance in reconstructing the paleoecology of the site. Because the fossil record of most extant cercopithecid genera is rather sparse at Plio-Pleistocene sites in Africa, Kanam East represents one of only a few sites that has yielded material that can be assigned toColobus,Lophocebus, orCercopithecus. The fossil monkeys from the site, therefore, provide additional evidence to help reconstruct the paleobiology, as well as the patterns of species diversity and community structure that characterized the cercopithecid radiation during the Plio-Pleistocene.     

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.     

Structure, floristic composition, and vegetation forming factors of three vegetation types in Senegal

Six 1 ha plots were established in a coastal savanna, called Fathala Forest, in Delta du Saloum National Park, Senegal. Two plots were placed in woodland, two in wooded grassland, and two in transition woodland in order to describe structure and floristic composition of the vegetation. All trees ≥ 5 cm dbh were sampled. The three selected vegetation types showed distinct differences in structure as well as in species composition. Woodland had high density (440–449 individuals per ha), many small trees, and high basal area (13.4 m²per ha). Transition woodland was characterised by low density (54–118 individuals per ha) but many large trees and a relatively large basal area (8.6–12.8 m² per ha). Wooded grassland was characterised by medium sized trees, it had low density (86–102 individuals per ha) and low basal area (3.8–5.7 m² per ha). Species richness ranged between 17 and 27 species per ha in the six plots. Only two species were found in all plots, Daniellia oliveri (Caesalpiniaceae) and Prosopis africana (Mimosaceae). Legumes dominated all plots. Wooded grassland and transition woodland had many characteristics of fire-affected vegetation in contrast to woodland. Today wooded grassland encroaches on woodland and transition woodland. Management of the latter two vegetation types should be given priority as they maintain structural and floristic characteristics that are essential to conserve biodiversity and original features of the vegetation, and they are also important for local people who are allowed to make sustainable use of the vegetation.     

Exploring methods for rapid assessment of woody vegetation in the Batemi Valley, North-central Tanzania

Conservation of local biological resources in remote areas requires efficient data and collection methods. This paper describes part of a local conservation initiative in Northern Tanzania in which an indigenous conservation group enlisted the support of outside scientists to explore means of preparing baseline ecological reports. Two factors are seen as important: one is local use of ecological resources and the other is local availability. This paper focuses on the second of these and considers woody species. A variety of ecological field methods, statistical analysis and remote sensing and mapping techniques are used to generate baseline ecological inventories. The fieldwork identified 101 woody species, representing 54 genera and 37 families in the Batemi area. There are three main vegetation types: Vangueria apiculata-Ficus sycomorus-Trichilia emetica type; Croton dictygamous-Euphorbia tirucalli-Grewia bicolor type; and Acacia tortilis-Balanites aegyptica-Euphorbia candelabrum type. The Landsat TM map identified four main land-cover classes: (1) bushland and woodland thicket, (2) woodland (3) wooded grassland, and (4) grassland with scattered trees, which includes agricultural areas and villages. The combination of these data and methods can be useful for conservation planning and long-term monitoring, but it is clear that ground-level local assessment is necessary to detect subtleties of human-environment interaction that are required for conservation planning.     

The deciduous lower dentition of Ouranopithecus macedoniensis (Primates, Hominoidea) from the late Miocene deposits of Macedonia, Greece

Two mandibular fragments with associated milk teeth assigned to the late Miocene hominoid primate Ouranopithecus macedoniensis are analyzed. The fossils, which belong to a single individual, were found in the Vallesian locality of "Ravin de la Pluie" of the Axios Valley (Macedonia, Greece). The material is described here and compared with extant and extinct hominoids, allowing assessment of the evolutionary trends in the deciduous lower dentition within the Hominoidea. Hylobatids represent the more primitive pattern. Gorilla is slightly more derived than hylobatids, but less derived than Pongo and Pan, the latter being the most derived. With relatively smaller deciduous canines and more molarized deciduous premolars, Ouranopithecus is more derived than both Pan and Gorilla. Among the fossil hominoids, Proconsul, representing the primitive condition, has a very simple dp(3)and a dp(4)that has a trigonid that is taller than the talonid and which lacks a hypoconulid. Griphopithecus is more derived than Proconsul in having a dp(4) with a lower trigonid, a hypoconulid, and a less oblique cristid obliqua. Australopithecus and Paranthropus possess a similar morphology to that of Homo, while Ardipithecus appears to be more primitive than the latter genera. Ouranopithecus has a more derived lower milk dentition than Proconsul and Griphopithecus, but less derived than Australopithecus and Paranthropus. The comparison of the lower milk dentition of Ouranopithecus confirms our previous conclusions suggesting that this fossil hominoid shares derived characters with Australopithecus and Homo.     

The Pleistocene archaeology and environments of the Wasiriya Beds, Rusinga Island, Kenya

Western Kenya is well known for abundant early Miocene hominoid fossils. However, the Wasiriya Beds of Rusinga Island, Kenya, preserve a Pleistocene sedimentary archive with radiocarbon age estimates of >33–45 ka that contains Middle Stone Age artifacts and abundant, well-preserved fossil fauna: a co-occurrence rare in eastern Africa, particularly in the region bounding Lake Victoria. Artifacts and fossils are associated with distal volcanic ash deposits that occur at multiple localities in the Wasiriya Beds, correlated on the basis of geochemical composition as determined by electron probe microanalysis. Sediment lithology and the fossil ungulates suggest a local fluvial system and associated riparian wooded habitat within a predominantly arid grassland setting that differs substantially from the modern environment, where local climate is strongly affected by moisture availability from Lake Victoria. In particular, the presence of oryx (Oryx gazella) and Grevy’s zebra (Equus grevyi) suggest a pre-Last Glacial Maximum expansion of arid grasslands, an environmental reconstruction further supported by the presence of several extinct specialized grazers (Pelorovis antiquus, Megalotragus sp., and a small alcelaphine) that are unknown from Holocene deposits in eastern Africa. The combination of artifacts, a rich fossil fauna, and volcaniclastic sediments makes the Wasiriya Beds a key site for examining the Lake Victoria basin, a biogeographically important area for understanding the diversification and dispersal of Homo sapiens from Africa, whose pre-Last Glacial Maximum history remains poorly understood.     

Species composition,abundance and habitat association of non-volant small mammals in Gibe Sheleko National Park,southwestern Ethiopia

The objective of this study was to assess the species composition, abundance and habitat association of non-volant small mammals from grassland, Acacia woodland, farmland, riverine forest, bushland and wooded grassland habitats in Gibe Sheleko National Park, southwestern Ethiopia. Data were collected using 49 Sherman live traps in 70 × 70 m sized girds and visual observations from December 2018 to August 2020. A total of 937 small mammals belonging to 10 species were captured and directly identified. The identified small mammal species and their relative abundance include Arvicanthis niloticus (7.04%), Crocidura olivieri (1.92%), Grammomys dolichurus (3.84%), Lemniscomys striatus (10.25%), Mastomys awashensis (24.55%), Mastomys natalensis (33.83%), Mus tenellus (0.85%), Myomys fumatus (6.30%), Rattus rattus (4.70%) and Stenocephalemys albipes (6.72%). Hystrix cristata, Xerus rutilus and Tachyoryctes splendens were documented through observation. The highest number of species (6) was registered at farmland and wooded grassland followed by bushland and riverine forest (5) and Acacia woodland and grassland (4). Lemniscomys striatus, M. awashensis and M. natalensis were common in all habitats. More, 216 (23.05%) individuals were recorded in farmland, while the least, 111 (11.85%) were recorded in Acacia woodland. The study area has various topographical land settings additional study is needed using different traps.     

New wrist bones of Proconsul africanus and P. nyanzae from Rusinga Island, Kenya

The anatomy of the wrist of two species of the early Miocene hominoid Proconsul is described based on new material collected on Rusinga Island, Kenya. These fossils generally confirm previous findings that the wrist of Proconsul is monkey-like in much of its morphology. However, the structure of the ulnar side of the wrist, particularly the ulnocarpal joint, is significantly different from that of extant monkeys and suggests some functional affinities with extant hominoids. Thus the wrist of Proconsul is neither monkey-like nor ape-like in its total morphology. Instead, it shows a unique combination of features which once again point to the oversimplicity of forcing fossil forms into categories based only on extant taxa.     

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.     

Faunal correlation of Wadi Moghara, Egypt: implications for the age of Prohylobates tandyi

Wadi Moghara, Egypt, is an early Miocene fossil locality with a mammalian fauna that includes Prohylobates tandyi, one of the earliest known representatives of the Cercopithecoidea. Faunal correlations were conducted between Moghara, Gebel Zelten (Libya) and a series of East African fossil sites with established radiometric dates in order to estimate the age of the Moghara mammals, including P. tandyi. Results confirm hypotheses proposed in some previous studies that: (1) Moghara is about 18-17 Ma, approximately the same age as the Hiwegi fauna from Rusinga Island (Kenya); (2) Moghara is slightly older than Gebel Zelten (Libya) (17-15 Ma); and (3) the cercopithecoid tooth presently identified as Victoriapithecus sp. from Napak V (ca. 19 Ma) is currently the oldest known record of a fossil Old World monkey, followed by P. tandyi from Moghara (Egypt) (18-17 Ma) and Prohylobates sp. from Buluk (Kenya) (>17.2 Ma), P. simonsi from Gebel Zelten (Libya) (ca. 17-15 Ma), and V. macinnesi from Maboko (Kenya) (ca. 16-14.7 Ma).     

Palaeoenvironment examination of the terminal Miocene hominoid locality of the Zhaotong Basin,southwestern China,based on the rhinocerotid remains

Anatomic modification in evolution process of mammals was closely correlated with the environmental changes, and become the powerful evidence for reconstructing the palaeoenvironment shaped their evolution. Rhinocerotid fossils are important indicators of the ecosystems inhabited by the mammalian faunas. Here, we first described remains of two rhinocerotids from the terminal Miocene Zhaotong Basin, the most recent hominoid locality in South China, including Acerorhinus lufengensis and Rhinocerotini gen. et sp. indet. New remains of A. lufengensis display a short crochet and antecrochet, expanded lingual cones, and rounded labial wall of the trigonid and talonid. These characteristics demonstrate its feeding habits of grazing brush and high grass. The limb bones of Rhinocerotini gen. et sp. indet. enable to live in an open habitat in having the following characteristics: the Mc II facet of Mc III is large, oval, flattened, and nearly vertical in direction; the femur exhibits a very large trochanter tertius and two nearly parallel asymmetrical ridges of the distal patella trochlea. The rhinocerotid fossils described herein provide a substantial evidence of the presence of mosaic environment, and the grassland should patches within or along the margin of the forest in the terminal Miocene Shuitangba locality.