Christopher C Gilbert

City University of New York - Hunter College | Hunter CUNY · Department of Anthropology

Although there have been a few reports of macromammals from the Siwalik site of Dunera, no micromammals have yet been described. Recently, a diverse micromammal fossil assemblage represented by isolated teeth has been recovered from Dunera. The specimens are identified as a murine similar to Progonomys hussaini (Progonomys cf. hussaini), the ctenod...

Despite recent advances in chronometric techniques (e.g., Uranium-Lead [U-Pb], cosmogenic nuclides, electron spin resonance spectroscopy [ESR]), considerable uncertainty remains regarding the age of many Plio-Pleistocene hominin sites, including several in South Africa. Consequently, biochronology remains important in assessments of Plio-Pleistocen...

The fossil record of treeshrews, hedgehogs, and other micromammals from the Lower Siwaliks of India is sparse. Here, we report on a new genus and species of fossil treeshrew, specimens of the hedgehog Galerix , and other micromammals from the middle Miocene (Lower Siwalik) deposits surrounding Ramnagar (Udhampur District, Jammu and Kashmir), at a f...

The Early Pleistocene was a critical time period in the evolution of eastern African mammal faunas, but fossil assemblages sampling this interval are poorly known from Ethiopia’s Afar Depression. Field work by the Hadar Research Project in the Busidima Formation exposures (~2.7–0.8 Ma) of Hadar in the lower Awash Valley, resulted in the recovery of...

The Colobines are a group of Afroeurasian monkeys that exhibit extraordinary behavioural and ecological diversity. With long tails and diverse colourations, they are medium-sized primates, mostly arboreal, that are found in many different habitats, from rain forests and mountain forests to mangroves and savannah. Over the last two decades, our unde...

The living guenons (Cercopithecini, Cercopithecidae) are speciose and widely distributed across sub-Saharan Africa but are poorly represented in the fossil record. In addition, the craniodental and skeletal similarity of the guenons has hampered the identification of fragmentary material, likely obscuring the taxonomic diversity represented in the...

Fossil primates of the Baynunah Formation are represented by only two cercopithecoid specimens: AUH 35, a male lower canine of an indeterminate cercopithecid from site JDH-3, and AUH 1321, a lower molar of a guenon from site SHU 2–2. Although rare, these cercopithecoid primates are significant in terms of their age and biogeographic implications. A...

Fossil primates of the Baynunah Formation are represented by only two cercopithecoid specimens: AUH 35, a male lower canine of an indeterminate cercopithecid from site JDH-3, and AUH 1321, a lower molar of a guenon from site SHU 2-2. Although rare, these cercopithecoid primates are significant in terms of their age and biogeographic implications. A...

Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relat...

Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relat...

Old World monkeys, or cercopithecoids, are a diverse and widespread group of primates found throughout Africa and Asia. They are characterised by their specialised molar teeth, quadrupedal posture and locomotor behaviour, often spending more time on the ground than other primates, as well as their frequently large and complex social groups. They su...

Objectives: The little known guenon Cercopithecus dryas has a controversial taxonomic history with some recognizing two taxa (C. dryas and C. salongo) instead of one. New adult specimens from the TL2 region of the central Congo Basin allow further assessment of C. dryas morphology and, along with CT scans of the juvenile holotype, provide ontogene...

This chapter examines hypothesized dispersal events between Africa and Eurasia involving non-cercopithecoid catarrhines, particularly hominoid apes, and reviews the tectonic and climatic events that may have had a role in shaping them. All available evidence points to hominoid origins in Africa by the latest Oligocene, and the earliest evidence for...

The fossil record of ‘lesser apes’ (i.e. hylobatids = gibbons and siamangs) is virtually non-existent before the latest Miocene of East Asia. However, molecular data strongly and consistently suggest that hylobatids should be present by approximately 20 Ma; thus, there are large temporal, geographical, and morphological gaps between early fossil ap...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Objectives: The guenons (tribe Cercopithecini) are a diverse and primarily arboreal radiation of Old World monkeys from Africa. However, preliminary behavioral observations of the lesula (Cercopithecus lomamiensis), a little-known guenon species described in 2012, report it spending substantial amounts of time on the ground. New specimens allow us...

A Sivapithecus m3 from Ramnagar is described and the taxonomy of all Sivapithecus specimens from Ramnagar is reviewed.

African papionins are a highly successful subtribe of Old World monkeys with an extensive fossil record. On the basis of both molecular and morphological data, crown African papionins are divided into two clades: Cercocebus/Mandrillus and Papio/Lophocebus/Rungwecebus/Theropithecus (P/L/R/T), though phylogenetic relationships in the latter clade, am...

Cribra orbitalia is one of the most frequent pathological lesions seen in ancient and historic human skeletal remains. The biological causes of this abnormality have been debated, but they are almost always linked to malnutrition and disease. The purpose of this project is to determine if cribra orbitalia also correlates with craniofacial fluctuati...

Baboons (Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi, Papio robinsoni and Papio angusticeps. Because of their derived...

An M3 of a catarrhine primate was recently recovered from Lower Siwalik deposits (~14-11 Ma) at the site of Sunetar near Ramnagar, India. Preliminary studies have shown that this Hylobates agilis-size tooth is distinct from the M3s of other primates found in the area, including Sivapithecus and Sivaladapis, and broader morphological comparisons ind...

Despite sporadic fieldwork for nearly a century, the Middle Miocene hominoid locality of Ramnagar (Jammu and Kashmir, India) is still not well understood in terms of its taphonomy and paleoecology. Between 2010–2015, we collected a large number of vertebrate, invertebrate and plant fossil remains from seven sites in the Ramnagar area: Bassi, Kulwan...

The living guenons (Tribe Cercopithecini) are largely an arboreal radiation, but the recognition of patas, vervets, and L’Hoest’s monkeys as a clade suggests a single evolutionary transition to terrestriality within the tribe. Recently, a new guenon species was discovered in the TL2 region of the Democratic Republic of the Congo, the lesula (Cercop...

Objective Ecological niche modeling (ENM) has been used to assess how abiotic variables influence species distributions and diversity. Baboons are broadly distributed throughout Africa, yet the degree of climatic specialization is largely unexplored for individual taxa. Also, the influence of climate on baboon phylogenetic divergence is unknown. In...

The evolutionary history of extant hominoids (humans and apes) remains poorly understood. The African fossil record during the crucial time period, the Miocene epoch, largely comprises isolated jaws and teeth, and little is known about ape cranial evolution. Here we report on the, to our knowledge, most complete fossil ape cranium yet described, re...

Ecological niche modeling (ENM) has been used to assess species diversity and delineation in relation to abiotic factors. In this study, we use ENM to investigate how niches vary across Papio species in an attempt to understand the ecological or climatic variables that have influenced their taxonomic diversity. Using Maxent to generate niche models...

John Fleagle (1948–) has been a leading primatologist, paleoprimatologist, and functional anatomist for the past four decades. A 1988 MacArthur Fellowship Awardee, his research has spanned all major subfields in evolutionary anthropology, including primate behavior, primate evolution, and human evolution, with major contributions in each area. Draw...

Over the past century, numerous vertebrate fossils collected near the town of Ramnagar, India, have proven to be important for understanding the evolution and biogeography of many mammalian groups. Primates from Ramnagar, though rare, include a number of hominoid specimens attributable to Sivapithecus, as well as a single published mandibular fragm...

In 1922, on the advice of prominent geologist and local Superintendent Charles Middlemiss, Barnum Brown began systematic collection of vertebrate fossils from Lower Siwalik deposits surrounding the town of Ramnagar (Jammu and Kashmir), India. Brown immediately discovered a partial jaw belonging to a large hominoid ape and described it as a new spec...

Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy of the canals for the promontorial and stapedial branc...

Objectives: Extant primate crania represent a small subset of primate crania that have existed. The main objective here is to examine how the inclusion of fossil crania changes our understanding of primate cranial diversity relative to analyses of extant primates. We hypothesize that fossil taxa will change the major axes of cranial shape, occupy...

Fossil monkeys have long been used as important faunal elements in studies of African Plio-Pleistocene biochronology, particularly in the case of the South African karst cave sites. Cercopithecoid fossils have been known from Tanzania's Olduvai Gorge for nearly a century, with multiple taxa documented including Theropithecus oswaldi and Cercopithec...

Paradolichopithecus is a large, terrestrially-adapted Pliocene fossil cercopithecine from Europe and Central Asia. While many previous studies have noted that Paradolichopithecus shares a number of craniofacial features with Macaca (e.g., rounded muzzle, lack of facial fossae, lack of anteorbital drop), a few others have instead suggested it shares...

This study investigates the taxonomic and morphometric affinities of a newly catalogued fossil papionin from Kromdraai A. The juvenile specimen (KA 5993), which preserves the face and cranial base anterior to the spheno-occipital synchondrosis, is notable for its small size and well-developed maxillary fossae. Geometric morphometric analyses were c...

Although variation in cranial arterial presence, route and development has been shown to provide indications of phylogenetic relationship in primates, information on relative area of the promontorial and stapedial bony canals has never been comprehensively quantified. Among fossil euprimates, some genera (notably Mahgarita, Notharctus, and Rooneyia...

A new partial cranium (UW 88-886) of the Plio-Pleistocene baboon Papio angusticeps from Malapa is identified, described and discussed. UW 88-886 represents the only non-hominin primate yet recovered from Malapa and is important both in the context of baboon evolution as well as South African hominin site biochronology. The new specimen may represen...

The African papionin primates commonly known as mangabeys form a diphyletic group with white-eyelid mangabeys (Cercocebus) being most closely related to drills and mandrills (Mandrillus). However, the phylogenetic relationships among members of the Cercocebus-Mandrillus clade have not been investigated in detail, particularly from a morphological p...

In his recent article “Primates in the Eocene”, Gingerich (2012) presented a broad review of Eocene primate radiations and their place in the primate evolutionary tree, with a particular focus on Adapoidea. While synthetic reviews of early primate evolution are always welcome additions to the literature, within his larger analysis Gingerich (2012)...

Thumb reduction is among the most important features distinguishing the African and Asian colobines from each other and from other Old World monkeys. In this study we demonstrate that the partial skeleton KNM-ER 4420 from Koobi Fora, Kenya, dated to 1.9 Ma and assigned to the Plio-Pleistocene colobine species Cercopithecoides williamsi, shows marke...

The fossil colobine genus Cercopithecoides is temporally, geographically, and morphologically diverse. There are currently six species recognized from Late Miocene to Pleistocene sites in Africa with a possible seventh form present at Kromdraai B and Swartkrans in South Africa, for which the name C. coronatus (Freedman, 1957) is available. We focus...

Phylogeny is associated with most aspects of the biology of primates and other animals, such as body form, locomotion, gross diet, and social behavior. Closely related organisms tend to be similar to one another. In this article we examine the extent to which the dietary overlap of individual primate species within a community reflects their phylog...

Significance The primate subfamily Cercopithecinae represents the most diverse and successful living Old World primate group, with a current distribution throughout Africa and Asia. However, how and when these monkeys dispersed out of Africa is not well understood. This paper is significant in its description of a ∼6.5–8.0 million-y-old fossil guen...

Significance Mammalian extinction during the past several hundred thousand years has been a major focus for evolutionary biologists, geologists, and archaeologists, often being linked to climate change and human overhunting. Until relatively recently, study has been largely restricted to the Americas, Europe, and Australasia. We present the oldest...

The taxonomy of the fossil colobine genus Cercopithecoides has been debated by paleoprimatologists for decades. Currently, six species of Cercopithecoides are recognized in the Late Miocene to Plio-Pleistocene of South and East Africa. C. williamsi, found at Koobi Fora, Leba, Makapansgat, Sterkfontein, Swartkrans, Bolt’s Farm, and Kromdraai, is one...

Over the past century, numerous specimens collected near Ramnagar (Jammu and Kashmir Province, India) have proven important in understanding the evolution and biogeography of many mammalian groups, including hominoid apes. The precise geochronology of the Ramnagar-area deposits, however, remains uncertain and is an active topic of research. Since 2...

Taxonomy of the South African fossil colobine Cercopithecoides williamsi has been debated by paleoprimatologists for decades. It has been suggested that the cranial morphology of specimens from Makapansgat (MP), Sterkfontein (STS/W), and Bolt's Farm (BF) shows more variation than expected for a single species. Thirty-seven three-dimensional landmar...

The modern Old World Monkeys (Superfamily Cercopithecoidea, Family Cercopithecidae) can be traced back into the late Miocene, but their origin and subsequent diversification is obscured by the scarcity of terrestrial fossil sites in Africa between 15 and 6 Ma. Here, we document the presence of cercopithecids at 12.5 Ma in the Tugen Hills of Kenya....

This study examines African papionin phylogenetic history through a comprehensive cladistic analysis of extant and fossil craniodental morphology using both quantitative and qualitative characters. To account for the well-documented influence of allometry on the papionin skull, the general allometric coding method was applied to characters determin...

Recently, we described ~12.5 million year old fossil colobine teeth from the Tugen Hills, Kenya. These specimens represent the earliest colobine and the earliest cercopithecid specimens in the fossil record by ~3 million years. In addition, recent expeditions to the Baynunah Formation, Emirate of Abu Dhabi, UAE, have resulted in the recovery of a f...

In June 2007, a previously undescribed monkey known locally as "lesula" was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC). We describe this new species as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted...

Maximum likelihood tree, TSPY. Phylogram and bootstrap support values (500 replicates) were inferred using GARLI 0.951. The topology is identical to that inferred using a Bayesian approach (Fig. S2). Cercopithecus lomamiensis and C. hamlyni are reciprocally monophyletic. The scale at the bottom is in units of nucleotide substitutions per site. (PDF...

Bayesian tree, TSPY. Phylogram and clade credibility scores were obtained using MRBAYES 3.11. The topology is identical to the ML tree. The scale at the bottom is in units of nucleotide substitutions per site. (PDF)

Maximum likelihood tree, Xq13.3 homolog. The scale at the bottom is in units of nucleotide substitutions per site. (PDF)

Bayesian tree, Xq13.3 homolog. The scale at the bottom is in units of nucleotide substitutions per site. (PDF)

Specimens of Cercopithecus lomamiensis and Cercopithecus hamlyni examined for this study. (PDF)

Genetic samples list. (PDF)

Acoustic parameters measured for each sampled boom. (PDF)

Brief descriptions of Cercopithecus lomamiensis crania examined (by specimen). (PDF)

Comparative craniodental measurements between Cercopithecus lomamiensis and Cercopithecus hamlyni . (PDF)

Parameters of boom calls of Cercopithecus hamlyni and Cercopithecus lomamiensis . (PDF)

DNA sequence alignment for the Xq13.3 homolog. (NEX)

Selected cranial measurements of Cercopithecus lomamiensis (to the nearest tenth of a millimeter). (PDF)

Cranial landmarks used in the 3-dimensional comparative analysis of cranial morphology. (PDF)

Estimated divergence dates (million years ago) in Cercopithecid lineages A) TSPY, B) Xq13.3 homolog. Constrained nodes are marked with *. (PDF)

Information and references on divergence date calibration methods. (PDF)

Exemplars of booms by Cercopithecus hamlyni . (AIF)

DNA sequence alignment for TSPY. (NEX)

Exemplars of booms by Cercopithecus lomamiensis . (AIF)

Among fossil primates, the Eocene adapiforms have been suggested as the closest relatives of living anthropoids (monkeys, apes, and humans). Central to this argument is the form of the second pedal digit. Extant strepsirrhines and tarsiers possess a grooming claw on this digit, while most anthropoids have a nail. While controversial, the possible p...