African Anthropoids Research Articles

A New Humerus of Homunculus patagonicus, a Stem Platyrrhine from the Santa Cruz Formation (Late Early Miocene), Santa Cruz Province, Argentina

We describe a well-preserved humerus of Homunculus patagonicus, a stem platyrrhine from the late early Miocene of the Santa Cruz Formation, Santa Cruz Province, Argentina. The distal part of a humerus was collected by Carlos Ameghino and figured in the 19th Century, but is now lost. Other described postcranial elements, also collected by him include a femur and a partial radius. Comparative observations are made with living and extinct platyrrhines, Oligocene African anthropoids, and extant strepsirrhines. Homunculus patagonicus was a robustly built arboreal quadruped that weighed between 2.2 and 2.6 kg. There is no evidence that the elbow could be fully extended as in living suspensory platyrrhines like Ateles. The medial orientation of the epicondyle suggests that the finger and wrist flexors were not aligned with the long axis of the limb, a distinction from more cursorial monkeys (extant cercopithecoids and the Cuban Pleistocene fossil platyrrhine Paralouatta have retroflexed medial epicondyles). Overall, the morphology is typically platyrrhine although the bone is quite robust. The robustness of the humerus is most comparable to that of early anthropoids from Africa rather than any extant platyrrhine.

A new parapithecine (Primates: Anthropoidea) from the early Oligocene of Libya supports parallel evolution of large body size among parapithecids

Parapithecines are an extinct subfamily of stem anthropoid primates previously known only from the Jebel Qatrani Formation in Egypt. Here, we describe isolated teeth pertaining to Simonsius harujensis sp. nov., a relatively small-bodied parapithecine from strata near Zallah Oasis in the Sirt Basin of central Libya that is estimated to date to ∼31 Ma on the basis of mammalian biostratigraphy. The dental morphology of S. harujensis sp. nov. is generally intermediate between that of the closely related parapithecines Parapithecus fraasi and Simonsius grangeri, highlighting some of the anatomical features distinguishing the latter taxa and providing further support for their generic separation. A phylogenetic analysis using parsimony methods was performed on a character-taxon matrix incorporating data from the new Libyan parapithecine, virtually all other parapithecids and the proteopithecid Proteopithecus sylviae. Results of this analysis suggest that parapithecids comprise a basal clade consisting of three species of Biretia and a more derived clade including Parapithecinae (Parapithecus and Simonsius) and Qatraniinae (Qatrania, Ucayalipithecus, and Apidium). Body mass estimates for parapithecids were calculated on the basis of regression equations generated to predict body mass from the occlusal area of upper and lower cheek teeth in extant anthropoids. The relatively small body mass of S. harujensis sp. nov. and its reconstructed phylogenetic position as the sister group of S. grangeri, which is the largest known parapithecid, support the convergent acquisition of body mass larger than 500 g among multiple clades of early Oligocene African anthropoids. The new Libyan parapithecine augments previously reported evidence supporting a substantial degree of faunal provincialism across northern Africa/Arabia during the early Oligocene.

Upper molar morphology of the early oligocene egyptian anthropoid Qatrania wingi.

Qatrania wingi is a poorly documented fossil anthropoid known only from Quarry E in the Jebel Qatrani Formation, Fayum Depression, Egypt. This report augments our knowledge of the dental morphology of Qatrania in order to clarify its phylogenetic relationships with other early African anthropoids. YPM 18008 from Quarry E is the first example of an upper molar fragment that can reasonably be assigned to Qatrania wingi. Maximum parsimony phylogenetic analyses incorporating the new data from YPM 18008 were performed. If YPM 18008 is treated as a separate OTU, it is reconstructed as a member of Qatraniinae (the parapithecid clade containing Qatrania and Apidium). The only qatraniine known to occur at Quarry E is Qatrania wingi, and YPM 18008 is allocated to this species based on its size, provenance, and morphology. Despite its small size and early stratigraphic occurrence, the upper molar morphology of Qatrania wingi is highly derived with respect to that of other parapithecids aside from Apidium. Like that of Apidium, the upper molar morphology of Qatrania bears multiple neomorphic cusps and cuspules. These features appear to be synapomorphies linking Apidium and Qatrania to the exclusion of other parapithecids for which upper molar morphology is known, namely Simonsius grangeri and Biretia spp. YPM 18008 supports the recent proposal of a Qatrania + Apidium clade within Parapithecidae. This conflicts with earlier hypotheses, in which Qatrania was reconstructed as being phylogenetically basal to a clade including the younger, larger-bodied parapithecid taxa Apidium, Parapithecus, and Simonsius.

Eocene primates of South America and the African origins of New World monkeys.

The platyrrhine primates, or New World monkeys, are immigrant mammals whose fossil record comes from Tertiary and Quaternary sediments of South America and the Caribbean Greater Antilles. The time and place of platyrrhine origins are some of the most controversial issues in primate palaeontology, although an African Palaeogene ancestry has been presumed by most primatologists. Until now, the oldest fossil records of New World monkeys have come from Salla, Bolivia, and date to approximately 26million years ago, or the Late Oligocene epoch. Here we report the discovery of new primates from the ?Late Eocene epoch of Amazonian Peru, which extends the fossil record of primates in South America back approximately 10million years. The new specimens are important for understanding the origin and early evolution of modern platyrrhine primates because they bear little resemblance to any extinct or living South American primate, but they do bear striking resemblances to Eocene African anthropoids, and our phylogenetic analysis suggests a relationship with African taxa. The discovery of these new primates brings the first appearance datum of caviomorph rodents and primates in South America back into close correspondence, but raises new questions about the timing and means of arrival of these two mammalian groups.

New Apterodontinae (Hyaenodontida) from the Eocene locality of Dur At-Talah (Libya): systematic, paleoecological and phylogenetical implications.

The African Hyaenodontida, mainly known from the Late Eocene and Early Oligocene Fayum depression in Egypt, show a very poor diversity in oldest Paleogene localities. Here we report new hyaenodontidans found in the late Middle Eocene deposits of Dur At-Talah (Central Libya), known to have recorded the earliest radiation of African anthropoids. The new hyaenodontidan remains are represented by dental and postcranial specimens comprising the historical material discovered by R.J.G. Savage in the last century and that of the recent Franco-Libyan campaigns. This material includes two apterodontines, in particular a subcomplete skeleton of Apterodon langebadreae nov. sp., bringing new postcranial elements to the fossil record of the genus Apterodon. Anatomical analysis of the postcranial remains of Dur At-Talah suggests a semi-aquatic lifestyle for Apterodon, a completely unusual locomotion pattern among hyaenodontidans. We also perform the first cladistic analysis of hyaenodontidans including apterodontines: Apterodon and Quasiapterodon appear close relatives to “hyainailourines”, in particular to the African Oligo-Miocene Metasinopa species. Apterodon langebadreae nov. sp. could be the most primitive species of the genus, confirming an African origin of the Apterodontinae and a further dispersion event to Europe before the early Oligocene. These data enhance our knowledge of early hyaenodontidan diversification into Africa and underline how crucial is the understanding of their evolutionary history for the improvement of Paleogene paleobiogeographic scenarii.

Late Middle Eocene primate from Myanmar and the initial anthropoid colonization of Africa

Reconstructing the origin and early evolutionary history of anthropoid primates (monkeys, apes, and humans) is a current focus of paleoprimatology. Although earlier hypotheses frequently supported an African origin for anthropoids, recent discoveries of older and phylogenetically more basal fossils in China and Myanmar indicate that the group originated in Asia. Given the Oligocene-Recent history of African anthropoids, the colonization of Africa by early anthropoids hailing from Asia was a decisive event in primate evolution. However, the fossil record has so far failed to constrain the nature and timing of this pivotal event. Here we describe a fossil primate from the late middle Eocene Pondaung Formation of Myanmar, Afrasia djijidae gen. et sp. nov., that is remarkably similar to, yet dentally more primitive than, the roughly contemporaneous North African anthropoid Afrotarsius. Phylogenetic analysis suggests that Afrasia and Afrotarsius are sister taxa within a basal anthropoid clade designated as the infraorder Eosimiiformes. Current knowledge of eosimiiform relationships and their distribution through space and time suggests that members of this clade dispersed from Asia to Africa sometime during the middle Eocene, shortly before their first appearance in the African fossil record. Crown anthropoids and their nearest fossil relatives do not appear to be specially related to Afrotarsius, suggesting one or more additional episodes of dispersal from Asia to Africa. Hystricognathous rodents, anthracotheres, and possibly other Asian mammal groups seem to have colonized Africa at roughly the same time or shortly after anthropoids gained their first toehold there.

Timing the origin of human malarias: the lemur puzzle

BackgroundTiming the origin of human malarias has been a focus of great interest. Previous studies on the mitochondrial genome concluded that Plasmodium in primates, including those parasitic to humans, radiated relatively recently during a process where host switches were common. Those investigations, however, assumed constant rate of evolution and tightly bound (fixed) calibration points based on host fossils or host distribution. We investigate the effect of such assumptions using different molecular dating methods. We include parasites from Lemuroidea since their distribution provides an external validation to time estimates allowing us to disregard scenarios that cannot explain their introduction in Madagascar.ResultsWe reject the assumption that the Plasmodium mitochondrial genome, as a unit or each gene separately, evolves at a constant rate. Our analyses show that Lemuroidea parasites are a monophyletic group that shares a common ancestor with all Catarrhini malarias except those related to P. falciparum. However, we found no evidence that this group of parasites branched with their hosts early in the evolution of primates. We applied relaxed clock methods and different calibrations points to explore the origin of primate malarias including those found in African apes. We showed that previous studies likely underestimated the origin of malarial parasites in primates.ConclusionsThe use of fossils from the host as absolute calibration and the assumption of a strict clock likely underestimate time when performing molecular dating analyses on malarial parasites. Indeed, by exploring different calibration points, we found that the time for the radiation of primate parasites may have taken place in the Eocene, a time consistent with the radiation of African anthropoids. The radiation of the four human parasite lineages was part of such events. The time frame estimated in this investigation, together with our phylogenetic analyses, made plausible a scenario where gorillas and humans acquired malaria from a Pan lineage.

Late middle Eocene epoch of Libya yields earliest known radiation of African anthropoids

Reconstructing the early evolutionary history of anthropoid primates is hindered by a lack of consensus on both the timing and biogeography of anthropoid origins. Some prefer an ancient (Cretaceous) origin for anthropoids in Africa or some other Gondwanan landmass, whereas others advocate a more recent (early Cenozoic) origin for anthropoids in Asia, with subsequent dispersal of one or more early anthropoid taxa to Africa. The oldest undoubted African anthropoid primates described so far are three species of the parapithecid Biretia from the late middle Eocene Bir El Ater locality of Algeria and the late Eocene BQ-2 site in the Fayum region of northern Egypt. Here we report the discovery of the oldest known diverse assemblage of African anthropoids from the late middle Eocene Dur At-Talah escarpment in central Libya. The primate assemblage from Dur At-Talah includes diminutive species pertaining to three higher-level anthropoid clades (Afrotarsiidae, Parapithecidae and Oligopithecidae) as well as a small species of the early strepsirhine primate Karanisia. The high taxonomic diversity of anthropoids at Dur At-Talah indicates either a much longer interval of anthropoid evolution in Africa than is currently documented in the fossil record or the nearly synchronous colonization of Africa by multiple anthropoid clades at some time during the middle Eocene epoch.

Diurnality, nocturnality, and the evolution of primate visual systems.

Much of the recent research on the evolution of primate visual systems has assumed that a minimum number of shifts have occurred in circadian activity patterns over the course of primate evolution. The evolutionary origins of key higher taxonomic groups have been interpreted by some researchers as a consequence of a rare shift from nocturnality to diurnality (e.g., Anthropoidea) or from diurnality to nocturnality (e.g., Tarsiidae). Interpreting the evolution of primate visual systems with an ecological approach without parsimony constraints suggests that the evolutionary transitions in activity pattern are more common than what would be allowed by parsimony models, and that such transitions are probably less important in the origin of higher level taxa. The analysis of 17 communities of primates distributed widely around the world and through geological time shows that primate communities consistently contain both nocturnal and diurnal forms, regardless of the taxonomic sources of the communities. This suggests that primates in a community will adapt their circadian pattern to fill empty diurnal or nocturnal niches. Several evolutionary transitions from one pattern to the other within narrow taxonomic groups are solidly documented, and these cases probably represent a small fraction of such transitions throughout the Cenozoic. One or more switches have been documented among platyrrhine monkeys, Malagasy prosimians, Eocene omomyids, Eocene adapoids, and early African anthropoids, with inconclusive but suggestive data within tarsiids. The interpretation of living and extinct primates as fitting into one of two diarhythmic categories is itself problematic, because many extant primates show significant behavioral activity both nocturnally and diurnally. Parsimony models routinely interpret ancestral primates to have been nocturnal, but analyses of morphological and genetic data indicate that they may have been diurnal, or that early primate radiations were likely to have generated both nocturnal and diurnal forms, especially given the unusual annual light regimes faced by Early Tertiary primates living outside today's latitudinal tropics. We review the essential morphology and physiology of the primate visual system to look for features that might constrain evolutionary switches, and we find that the pattern of variation within and among primate groups in eye size, corneal size, retinal morphology, and opsin distribution are all consistent with the idea that there is considerable evolutionary flexibility in the visual system. These results suggest that primate lineages may evolve from diurnal to nocturnal, and vice versa, more readily and more rapidly than has been suggested by the use of strict parsimony models. This has implications for interpreting the fossil record and reconstructing key evolutionary events in primate evolution.

Shaking the Earliest Branches of Anthropoid Primate Evolution

Primates living today are believed to share a common ancestor that originated in either Africa or Asia. Fossil examples of such anthropoid ancestors have been found in both continents, so pushing back the origins to a single location has been controversial. In their Perspective, Jaeger and Marivaux discuss results reported in the same issue by Seiffert et al. that may put part of the controversy to rest. Seiffert et al. describe the earliest and most complete African anthropoid fossils from the Fayum desert region of Egypt. Cranial and dental fossils of two different small species were found, and their character, especially the features of the fossil teeth, suggests an ancient evolutionary history in Africa. At the same time, the phylogenetic analysis of Seiffert et al. is consistent with the view that African anthropoids immigrated from Asia at a very early date, probably before the late Paleocene (60 million years ago), possibly followed by later waves of immigration.

The Primate Fossil Record

W. C. Hartwig (ed.). 2002. The Primate Fossil Record. Cambridge University Press, Cambridge, United Kingdom, 530 + xiv pp. ISBN 0-521-66315-6, price (cloth), $175.00. This valuable new volume challenges significant components of the normal view of primate history. In Chapter 1, the editor briefly comments that “… fossil primates have always been interpreted in light of how they might relate to living ones. Whether this tendency stems from scientific insight or myopia, a framework of closely related forms and conservative phylogenies has persevered.” In the normal view (e.g., Clark 1959; Eisenberg 1981; Fleagle 1999), the earliest primates were Plesiadapiformes (or were closely related to them) that “took to the trees” at the end of the Cretaceous. The suborder Prosimii emerged in the Eocene, and ancestral Anthropoidea diverged in the Late Eocene in Africa. Derived African anthropoids of the Oligocene that retained only 2 premolars founded our infraorder Catarrhini. The super-family Hominoidea radiated in East Africa and Eurasia beginning in the early Miocene, but by the Pliocene, specialized Cercopithecoidea (Old World monkeys) had replaced most hominoids. A bipedal African hominoid begat the family Hominidae during climatic perturbations of the Plio-Pleistocene. Fieldwork and analysis by the contributors to this book over the last 2 decades have revised several key points of this view, but the editor (Chapter 1) makes it clear that the volume is not a new synthesis of fossil and living primate sys-tematics. Instead, multiple systematic inferences coexist, supported by conflicting interpretations of the same evidence. Following the brief introduction, Rasmus sen reviews current functional models for the origin of the primates by reprising his observations of Caluromys derbianus to address 2 competing hypotheses, that primates were initially successful “visual predators” (Cartmill 1972) and that primates initially exploited fruits at terminal branches of …

Chronology of primate discoveries in Myanmar: influences on the anthropoid origins debate.

The history of primate paleontology in Asia is long and complex, beginning with the first discoveries of fossil primates on the Indian subcontinent in the early 1830's. The first Eocene mammals from Asia were collected in Myanmar and described in 1916, while the first primates, Pondaungia and Amphipithecus, were described in 1927 and 1937, respectively, both from the Pondaung Formation in Myanmar. For the next 60 years, these two Pondaung taxa remained as the only known Eocene primates from Myanmar and one of the few records of Eocene primates from all of Asia. Taxonomically, Pondaungia and Amphipithecus were linked with a number of different groups, including archaic, hoofed ungulates (condylarths), adapiform primates, omomyid primates, and anthropoids. While no consensus existed, Pondaungia and Amphipithecus were most commonly compared with anthropoids. Beginning in the late 1990s, new primates were discovered in Myanmar, including smaller-bodied forms such as Bahinia and Myanmarpithecus. Also, new and better specimens of the larger-bodied Pondaungia and Amphipithecus began to appear, including the first cranial and postcranial fragments. Evaluations based on these new specimens, especially the postcrania, indicate that the two larger-bodied Myanmar taxa are adapiform primates that show their closest affinities to North American notharctines. The smaller-bodied taxa remain enigmatic, but may share their closest affinities with North American and Asian omomyid primates and Asian Tarsius. None of the known Asian primate taxa appear closely related to African anthropoids, which suggests that true anthropoids did not reach Asia until the latest Oligocene or earliest Miocene. These facts make an Asian origin for Anthropoidea unlikely. Additional and earlier evidence from both Asia and Africa is required before the ultimate origin of anthropoids can be determined. It appears possible that true anthropoids were an ancient radiation that may have been part of a Gondwanan (southern hemisphere) community that is, at present, poorly sampled and little understood.

Diets of fossil primates from the Fayum Depression of Egypt: a quantitative analysis of molar shearing

Over the last 90 years, Eocene and Oligocene aged sediments in the Fayum Depression of Egypt have yielded at least 17 genera of fossil primates. However, of this diverse sample the diets of only four early Oligocene anthropoid genera have been previously studied using quantitative methods. Here we present dietary assessments for 11 additional Fayum primate genera based on the analysis of body mass and molar shearing crest development. These studies reveal that all late Eocene Fayum anthropoids were probably frugivorous despite marked subfamilial differences in dental morphology. By contrast, late Eocene Fayum prosimians demonstrated remarkable dietary diversity, including specialized insectivory (Anchomomys), generalized frugivory (Plesiopithecus), frugivory+insectivory (Wadilemur), and strict folivory (Aframonius). This evidence that sympatric prosimians and early anthropoids jointly occupied frugivorous niches during the late Eocene reinforces the hypothesis that changes in diet did not form the primary ecological impetus for the origin of the Anthropoidea. Early Oligocene Fayum localities differ from late Eocene Fayum localities in lacking large-bodied frugivorous and folivorous prosimians, and may document the first appearance of primate communities with trophic structures like those of extant primate communities in continental Africa. A similar change in primate community structure during the Eocene–Oligocene transition is not evident in the Asian fossil record. Putative large anthropoids from the Eocene of Asia, such as Amphipithecus mogaungensis,Pondaungia cotteri , and Siamopithecus eocaenus, share with early Oligocene Fayum anthropoids derived features of molar anatomy related to an emphasis on crushing and grinding during mastication. However, these dental specializations are not seen in late Eocene Fayum anthropoids that are broadly ancestral to the later-occurring anthropoids of the Fayum's upper sequence. This lack of resemblance to undisputed Eocene African anthropoids suggests that the “progressive” anthropoid-like dental features of some large-bodied Eocene Asian primates may be the result of dietary convergence rather than close phyletic affinity with the Anthropoidea.

Origin of anthropoidea: dental evidence and recognition of early anthropoids in the fossil record, with comments on the Asian anthropoid radiation.

Among the earliest fossil anthropoid primates known are Catopithecus browni, Serapia eocaena, Arsinoea kallimos, and Proteopithecus sylviae, from the late Eocene quarry L-41, Fayum Depression, Egypt. Two of these taxa, C. browni and S. eocaena, may be the oldest known members of the Propliopithecidae and Parapithecidae, respectively, while A. kallimos and P. sylviae are archaic anthropoids of less certain familial affiliation. Dental features of C. browni, S. eocaena, A. kallimos, and P. sylviae are compared with those of younger propliopithecids and parapithecids from the Fayum in order to determine the morphocline polarities of dental features among these early anthropoids. From this, a basal African anthropoid dental morphotype is constructed. Among the features of this morphotype are: dental formula of 2.1.3.3; incisors subvertically implanted and somewhat spatulate; p2 as large as p3, both lacking paraconids; p4 weakly obliquely oriented but not exodaenodont; all lower molars with small paraconids present; upper anterior premolars lacking protocone; upper molars with small, cingular hypocones, all cheek teeth nonbunodont; and canines projecting but not necessarily sexually dimorphic. Comparisons are made between this African anthropoid morphotype and two of the best-represented proposed basal anthropoids, Eosimias and Djebelemur, with the result that neither appears to be a good candidate to have been ancestral to the African anthropoids. Other possible basal simians such as Algeripithecus, Tabelia, and Biretia also are evaluated but are too poorly known for adequate analysis. The larger-bodied Asian primates Pondaungia, Amphipithecus, and Siamopithecus also are not likely ancestors for African anthropoids, but like Eosimias they may share a common ancestry. Despite many recent claims of an Asian origin for anthropoids, the evidence remains far from compelling. The true origins of Anthropoidea remain obscure.

The origin of platyrrhines: An evaluation of the Antarctic scenario and the floating island model.

This paper evaluates whether 1) protoplatyrrhines could have migrated to South America via Antarctica, and 2) the floating island model is a plausible transoceanic mode of dispersal for land vertebrates like protoplatyrrhines. Results show that Eocene Antarctica and Australia supported large and dense forests, and that the Antarctic fauna was comprised of many species of vertebrates, including placental and marsupial land mammals. However, no primate remains have ever been reported from these continents. Antarctica and South America were connected until the Middle Eocene (i.e., after the oldest Asian anthropoids), but two major water barriers existed between Antarctica and Asia since the Early Eocene. The Eocene and Oligocene water gap separating Africa and Antarctica was excessively large. Thus, all scenarios involving an Antarctic route have been rejected. The African scenario is difficult to falsify because only one water barrier existed, both paleowinds and paleocurrents were favorable, and Paleogene African anthropoids show phylogenetic affinities to platyrrhines. I tested whether a journey on a hypothetical floating island over the Paleogene Atlantic Ocean exceeds the survival limit of a genetically viable group of animals such as protoplatyrrhines. Studies of water deprivation suggest that they could have been able, with a body weight averaging 1 kg, to survive without water for at least 13 days. I have used the present Atlantic Ocean as a model for the velocity of Paleogene paleowinds and paleocurrents. Considering winds as the key accelerating force of floating islands, the Paleogene Atlantic water barrier could have been crossed, in the most conservative scenario, in 8 days at 50 Mya, 11 days at 40 Mya, and 15 days at 30 Mya. In order to survive a transoceanic journey, however, protoplatyrrhines had to be preadapted to strong seasonal variations in water availability in their original (African) environment. Once on the sea, their brains would have physiologically interpreted the rarity of water as the beginning of the dry season, and the group would have switched its diet to alternative foods, i.e., everything available on the floating island.

Age of the Earliest African Anthropoids

The earliest fossil record of African anthropoid primates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher primates from Egypt accords well with their primitive morphology compared with later Old World higher primates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America.

Puncture marks on early African anthropoids.

Field studies of living primates have shown that primate predation is a rare event. This must also have been true for past primate communities. In the Fayum Oligocene of Egypt, specimens of all four species of Upper Fossil Wood Zone primates show evidence of tooth puncture marks. Of the four potential groups of primate predators--the snakes, the raptors, the crocodiles, and the primitive carnivores or creodonts--only the crocodiles and the creodonts could have made these puncture marks. When one compares the feeding habits of living crocodiles and mammalian carnivores with the evidence from the Fayum, it appears that the Fayum primates were preyed upon and/or scavenged by mammalian carnivore-like animals. The dismemberment of the Fayum primates by Oligocene predators indicates, in part, why the Fayum fossil material is rarely articulated. Bone damage by predators may well set limits on what bone associations can be discovered in the Fayum even before the bones are scattered and buried by depositional processes.

Qatrania, new basal anthropoid primate from the Fayum, Oligocene of Egypt

Recent excavations in Egypt organized by the Geological Survey of Egypt and Duke University have recovered many fossil primate specimens, most of which come from upper levels of the Jebel Qatrani Formation (early Oligocene) including Aegyptopithecus, Propliopithecus, Parapithecus and Apidium1–3. Screening at Quarry E in lower levels of the formation has also revealed a new small anthropoid described as Qatrania wingi. Qatrania is a primitive member of the Parapithecidae and possibly most closely allied to Parapithecus fraasi. This new species is the earliest African anthropoid known, equal in age and from the same quarry as Oligopithecus4. Its small size and details of molar structure point to a mainly frugivorous diet like some extant African prosimians and South American callithrichids.

Comments on the adaptive strategy of the first African anthropoids

Fayum anthropoids ranged in body size from about 600 g to about 6,000 g. A similar range of body size is found among extant Cebidae. The Fayum primates are larger than any extant insectivorous primates; this fact probably rules out a predomi nantly insectivorous diet. The molar morphology of these animals is consistant with a frugivorous diet. Parapithecus grangeri stands apart from the other species in having better developed molar shearing, possibly indicating that it had more plant fiber in its diet. Relative orbit size suggests that Apidium may have been diurnal; orbit size for the other species is either unknown or cannot be interpreted. Aegyptopithecus had a relatively small brain by comparison with extant anthropoids, but had considerably reduced olfactory bulbs, and enhanced visual cortex, at a grade of organization comparable to that of extant anthropoids.

The ecology of oligocene African anthropoidea

African anthropoids are first recorded in Early Oligocene deposits of the Fayum Province, Egypt. Six genera and nine species are recognized. Estimated body weights for these taxa are based on the regression equation log10(B) = 2.86log10(L) + 1.37, whereB is the bodyweight in grams, and Lis the M2length in millimeters. The equation is derived from 106 species of living primates. Fayum species range in body weight from about 600 g (Apidium moustafai)to about 6000 g (Aegyptopithecus zeuxis).A similar range of body weight is found among extant Cebidae. The Fayum primates are larger than any extant insectivorous primates;this fact probably rules out a predominantly insectivorous diet. Extant frugivorous hominoids can be separated from folivorous hominoids on the basis of molar morphology. Folivorous apes (gorilla and siamang) have proportionately more shearing on their molars than do frugivorous species. Based on the hominoid analogy, the molar morphology of the Fayum species is consistent with a frugivorous diet. Parapithecus grangeristands apart from other Fayum species in having better developed molar shearing, possibly indicating that it had more fiber in its diet. Terrestrial species of Old World monkeys tend to have significantly higher molar crowns than do more arboreal species. This difference may relate to an increased amount of grit in the diet of the more terrestrial species, selecting for greater resistance to wear. Oligocene primates have molar crown heights consistent with a primarily arboreal mode of existence. However, the particularly high molar crowns of Parapithecus grangerisuggest that this species may have foraged on the ground to a considerable degree. Other evidence is advanced suggesting that Apidiummay have had a diurnal activity pattern.